基本情報

所属

• 理学研究院　物理学部門　量子物理学分野

職名

• 講師

学位

• 博士(理学)（新潟大学）

J-Global ID

• 201301090468845881

研究分野

• 自然科学一般 / 素粒子、原子核、宇宙線、宇宙物理にする理論

研究活動情報

論文

• Utility of antiproton-nucleus scattering for probing nuclear surface density distributions

  K. Makiguchi, W. Horiuchi, A. Kohama

  PHYSICAL REVIEW C 102 3 2020年09月 [査読有り][通常論文]
   

  Antiproton-nucleon ((p) over barN) total cross sections are typically 3-4 times larger than the NN ones at incident energies from a few hundreds to thousands MeV. We investigate antiproton-nucleus scattering as it could work as a probe of the nuclear structure giving the sensitivity differently from a proton probe. High-energy antiproton-nucleus reactions are reasonably described by the Glauber model with a minimal profile function that reproduces the (p) over barN and (p) over bar-C-12 cross section data. In contrast to the proton-nucleus scattering, we find that the complete absorption occurs even beyond the nuclear radius due to the large (p) over barN elementary cross sections, which shows stronger sensitivity to the nuclear density distribution in the tail region. This sensitivity is quantified in the total reaction cross sections with various density profiles for future measurement including neutron-rich unstable nuclei.
• The(29)F nucleus as a lighthouse on the coast of the island of inversion

  L. Fortunato, J. Casal, W. Horiuchi, Jagjit Singh, A. Vitturi

  COMMUNICATIONS PHYSICS 3 1 2020年07月 [査読有り][通常論文]
   

  The exotic, neutron-rich and weakly-bound isotope(29)F stands out as a waymarker on the southern shore of the island of inversion, a portion of the nuclear chart where the effects of nuclear forces lead to a reshuffling of the single particle levels and to a reorganization of the nuclear structure far from stability. This nucleus has become very popular, as new measurements allow to refine theoretical models. We review the latest developments and suggest how to further assess the structure by proposing predictions on electromagnetic transitions that new experiments of Relativistic Coulomb Excitation should soon become able to measure.The neutron-rich, weakly bound fluorine isotope(29)F has been extensively investigated theoretically, but its significance has been revived by recent experiments. The authors present the latest developments and make prediction on the electromagnetic transitions occurring in this isotope that may be observed in the near future.
• Core swelling in spherical nuclei: An indication of the saturation of nuclear density

  W. Horiuchi, T. Inakura

  PHYSICAL REVIEW C 101 6 2020年06月 [査読有り][通常論文]
   

  Background: Nuclear radius is one of the most important and basic properties of atomic nuclei and its evolution is closely related to the saturation of the nuclear density in the internal region but the systematics of the nuclear radii for the neutron-rich unstable nuclei is not well known.Purpose: Motivated by the recent interaction cross section measurement which indicates the Ca-48 core swelling in the neutron-rich Ca isotopes, we explore the mechanism of the enhancement of the neutron and proton radii for spherical nuclei.Methods: Microscopic Hartree-Fock calculations with three sets of Skyrme-type effective interactions are performed for the neutron-rich Ca, Ni, and Sn isotopes. The total reaction cross sections for the Ca isotopes are evaluated with the Glauber model to compare them with the recent cross section data.Results: We obtain good agreement with the measured cross sections and charge radii. The neutron and proton radii of the various "core" configurations are extracted from the full Hartree-Fock calculation and discuss the core swelling mechanism.Conclusions: The core swelling phenomena occur depending on the properties of the occupying valence single-neutron states to minimize the energy loss that comes from the saturation of the densities in the internal region, which appears to be prominent in light nuclei such as Ca isotopes.
• Two-Neutron Halo is Unveiled in F-29

  S. Bagchi, R. Kanungo, Y. K. Tanaka, H. Geissel, P. Doornenbal, W. Horiuchi, G. Hagen, T. Suzuki, N. Tsunoda, D. S. Ahn, H. Baba, K. Behr, F. Browne, S. Chen, M. L. Cortes, A. Estrade, N. Fukuda, M. Holl, K. Itahashi, N. Iwasa, G. R. Jansen, W. G. Jiang, S. Kaur, A. O. Macchiavelli, S. Y. Matsumoto, S. Momiyama, Murray, I, T. Nakamura, S. J. Novario, H. J. Ong, T. Otsuka, T. Papenbrock, S. Paschalis, A. Prochazka, C. Scheidenberger, P. Schrock, Y. Shimizu, D. Steppenbeck, H. Sakurai, D. Suzuki, H. Suzuki, M. Takechi, H. Takeda, S. Takeuchi, R. Taniuchi, K. Wimmer, K. Yoshida

  PHYSICAL REVIEW LETTERS 124 22 2020年06月 [査読有り][通常論文]
   

  We report the measurement of reaction cross sections (sigma(ex)(R)) of F-27,F-29 with a carbon target at RIKEN. The unexpectedly large sigma(ex)(R) and derived matter radius identify F-29 as the heaviest two-neutron Borromean halo to date. The halo is attributed to neutrons occupying the 2p(3/2) orbital, thereby vanishing the shell closure associated with the neutron number N = 20. The results are explained by state-of-the-art shell model calculations. Coupled-cluster computations based on effective field theories of the strong nuclear force describe the matter radius of F-27 but are challenged for F-29.
• Two-neutron halo structure of F-31 and a novel pairing antihalo effect

  H. Masui, W. Horiuchi, M. Kimura

  PHYSICAL REVIEW C 101 4 2020年04月 [査読有り][通常論文]
   

  Background: A newly identified drip-line nucleus F-31 offers a unique opportunity to study the two-neutron (2n) correlation at the east shore of the island of inversion where the N = 28 shell closure is lost. Purpose: We aim to present the first three-body theoretical results for the radius and total reaction cross sections of F-31. This will further help to investigate how the pairing and the breakdown of the N = 28 shell closure influence the formation of the 2n-halo structure and the antihalo effect in this mass region.Methods: A F-29+n + n three-body system is described by the cluster orbital shell model, and its total reaction cross section is calculated by the Glauber theory.Results: Our three-body calculations predict 3.48-3.70 fm for the root-mean-square radius of F-31, which corresponds to the total reaction cross section of 1530 (1410) to 1640 (1500) mb for a carbon target at 240 (900) MeV/nucleon. The binding mechanism and halo formation in F-31 are discussed.Conclusions: The present study suggests a novel antihalo effect in this mass region: When the pairing overcomes the energy gap between the p(3/2) and f(7/2) orbits, the inversion of the occupation number of these orbits takes place, and it diminishes the 2n-halo structure.
• Swelling of Doubly Magic Ca-48 Core in Ca Isotopes beyond N=28

  M. Tanaka, M. Takechi, M. Homma, M. Fukuda, D. Nishimura, T. Suzuki, Y. Tanaka, T. Moriguchi, D. S. Ahn, A. Aimaganbetov, M. Amano, H. Arakawa, S. Bagchi, K-H Behr, N. Burtebayev, K. Chikaato, H. Du, S. Ebata, T. Fujii, N. Fukuda, H. Geissel, T. Hori, W. Horiuchi, S. Hoshino, R. Igosawa, A. Ikeda, N. Inabe, K. Inomata, K. Itahashi, T. Izumikawa, D. Kamioka, N. Kanda, Kato, I, Kenzhina, I, Z. Korkulu, Y. Kuk, K. Kusaka, K. Matsuta, M. Mihara, E. Miyata, D. Nagae, S. Nakamura, M. Nassurlla, K. Nishimuro, K. Nishizuka, K. Ohnishi, M. Ohtake, T. Ohtsubo, S. Omika, H. J. Ong, A. Ozawa, A. Prochazka, H. Sakurai, C. Scheidenberger, Y. Shimizu, T. Sugihara, T. Sumikama, H. Suzuki, S. Suzuki, H. Takeda, Y. K. Tanaka, Tanihata, I, T. Wada, K. Wakayama, S. Yagi, T. Yamaguchi, R. Yanagihara, Y. Yanagisawa, K. Yoshida, T. K. Zholdybayev

  PHYSICAL REVIEW LETTERS 124 10 2020年03月 [査読有り][通常論文]
   

  Interaction cross sections for Ca42-51 on a carbon target at 280 MeV/nucleon have been measured for the first time. The neutron number dependence of derived root-mean-square matter radii shows a significant increase beyond the neutron magic number N = 28. Furthermore, this enhancement of matter radii is much larger than that of the previously measured charge radii, indicating a novel growth in neutron skin thickness. A simple examination based on the Fermi-type distribution, and mean field calculations point out that this anomalous enhancement of the nuclear size beyond N = 28 results from an enlargement of the core by a sudden increase in the surface diffuseness of the neutron density distribution, which implies the swelling of the bare Ca-48 core in Ca isotopes beyond N = 28.
• Energy dependence of total reaction cross sections for Ne-17 on a proton target

  T. Moriguchi, M. Amano, A. Ozawa, W. Horiuchi, Y. Abe, T. Fujii, R. Kagesawa, D. Kamioka, A. Kitagawa, M. Mukai, D. Nagae, M. Sakaue, S. Sato, S. Suzuki, T. Suzuki, T. Yamaguchi, K. Yokota

  NUCLEAR PHYSICS A 994 2020年02月 [査読有り][通常論文]
   

  We measured the energy dependence of the total reaction cross sections (sigma(R)) for the proton drip-line nucleus of neon isotopes, Ne-17, with a solid hydrogen target. The sigma(R) on a proton target in the low- and intermediate-energy regions were provided, where only a few values are available for unstable nuclei. The new data were compared with theoretical calculations using the Glauber model. In the low-energy region (similar to 100A MeV), the theoretical cross sections overestimate the experimental ones, whereas the theoretical ones significantly underestimate the experimental data in the intermediate energy region (similar to 300-500A MeV). We discuss several possibilities for solving this discrepancy. This work suggests the necessity of more careful investigations of the energy dependence of sigma(R) for various nuclei on a proton target to determine the nuclear size properties precisely. (C) 2019 Elsevier B.V. All rights reserved.
• Exploring two-neutron halo formation in the ground state of F-29 within a three-body model

  Jagjit Singh, J. Casal, W. Horiuchi, L. Fortunato, A. Vitturi

  PHYSICAL REVIEW C 101 2 2020年02月 [査読有り][通常論文]
   

  Background: The F-29 system is located at the lower-N boundary of the "island of inversion" and is an exotic, weakly bound system. Little is known about this system beyond its two-neutron separation energy (S-2n) with large uncertainties. A similar situation is found for the low-lying spectrum of its unbound binary subsystem F-28.Purpose: We investigate the configuration mixing, matter radius, and neutron-neutron correlations in the ground-state of F-29 within a three-body model, exploring the possibility of F-29 to be a two-neutron halo nucleus.Method: The F-29 ground-state wave function is built within the hyperspherical formalism by using an analytical transformed harmonic oscillator basis. The Gogny-Pires-Tourreil (GPT) nn interaction with central, spin-orbit, and tensor terms is employed in the present calculations, together with different core + n potentials constrained by the available experimental information on F-28.Results: The F-29 ground-state configuration mixing and its matter radius are computed for different choices of the F-28 structure and S-2n value. The admixture of d waves with pf components is found to play an important role, favoring the dominance of dineutron configurations in the wave function. Our computed radii show a mild sensitivity to the F-27+n potential and S-2n values. The relative increase of the matter radius with respect to the F-27 core lies in the range 0.1-0.4 fm depending upon these choices.Conclusions: Our three-body results for F-29 indicate the presence of a moderate halo structure in its ground state, which is enhanced by larger intruder components. This finding calls for an experimental confirmation.
• Two-Neutron Correlations in a Borromean 20C+n+n System: Sensitivity of Unbound Subsystems

  Singh Jagjit, Horiuchi W, Fortunato L, Vitturi A

  FEW-BODY SYSTEMS 60 3 2019年09月 [査読有り][通常論文]
  
• Emergence of nuclear clustering in electric-dipole excitations of Li-6

  Satsuka S, Horiuchi W

  PHYSICAL REVIEW C 100 2 2019年08月29日 [査読有り][通常論文]
  
• Complete Glauber calculations for proton-nucleus inelastic cross sections

  Hatakeyama S, Horiuchi W

  NUCLEAR PHYSICS A 985 20 - 37 2019年05月 [査読有り][通常論文]
  
• Neutron skin and signature of the N=14 shell gap found from measured proton radii of N17-22

  Bagchi S, Kanungo R, Horiuchi W, Hagen G, Morris T. D, Stroberg S. R, Suzuki T, Ameil F, Atkinson J, Ayyad Y, Cortina-Gil D, Dillmann I, Estrade A, Evdokimov A, Farinon F, Geissel H, Guastalla G, Janik R, Kaur S, Knoebel R, Kurcewicz J, Litvinov Yu A, Marta M, Mostazo M, Mukha I, Nociforo C, Ong H. J, Pietri S, Prochazka A, Scheidenberger C, Sitar B, Strmen P, Takechi M, Tanaka J, Tanaka Y, Tanihata I, Terashima S, Vargas J, Weick H, Winfield J. S

  PHYSICS LETTERS B 790 251 - 256 2019年03月10日 [査読有り][通常論文]
  
• Microscopic global optical potential for nucleon-nucleus systems in the energy range 50-400 MeV

  Furumoto T, Tsubakihara K, Ebata S, Horiuchi W

  PHYSICAL REVIEW C 99 3 2019年03月06日 [査読有り][通常論文]
  
• Measurement of proton-distribution radii of neutron-rich nitrogen isotopes

  Soumya Bagchi, Rituparna Kanungol, Wataru Horiuchi, Gaute Hagen, Titus D. Morris, Steven Ragnar Stroberg, Toshio Suzuki, Frederic Amei, Joel Atkinson, Yassid Ayyad, Dolores Cortina-Gil, Iris Dillmann, Alfredo Estrade, Alexey Evdokimov, Fabio Farinon, Hans Geissel, Giulia Guastalla, Rudolf Janik, Satbir Kaur, Ronja Knoebel, Jan Kurcewicz, Yury Litvinov, Michele Marta, Magdalena Mostazo, Ivan Mukha, Chiara Nociforo, Hooi Jin Ong, Stephane Pietri, Andrej Prochazka, Christoph Scheidenberger', Branislav Sitar, Peter Strmen, Maya Takechi, Junki Tanaka, Yoshiki Tanaka-, Isao Tanihata-, Satoru Terashima, Jossitt Vargas, Helmut Weick, John Stuart Winfield

  IV INTERNATIONAL CONFERENCE ON NUCLEAR STRUCTURE AND DYNAMICS (NSD2019) 223 2019年 [査読有り][通常論文]
   

  Measurement of root-mean-square radii of proton distributions of N17-22 from charge-changing cross section shows the emergence of thick neutron skin towards the neutron-drip line. Signature of N = 14 shell gap has been found in nitrogen isotopes along with the emergence of neutron halo in N-22. The measured radii are in good agreement with the shell model calculations.
• Analyzing supersymmetric transformed α-nucleus potentials with electric-multipole transitions

  T. Arai, W. Horiuchi, D. Baye

  Nuclear Physics A 977 82 - 100 2018年09月01日 [査読有り][通常論文]
   

  Alpha(4He or α)-cluster models have often been used to describe light nuclei. Towards the application to multi-cluster systems involving heavy clusters, we study the relative wave functions of the α+16O and α+40Ca systems generated from phase-shift-equivalent potentials. In general, a potential between clusters is deep accommodating several redundant bound states which should be removed in an appropriate way. To avoid such a complicated computation, we generate a shallow-singular potential by using supersymmetric transformations from the original deep potential. Changes in the relative wave functions by the transformations are quantified with electric-multipole transitions which give a different radial sensitivity to the wave function depending on their multipolarity. Despite the fact that the original and transformed potentials give exactly the same phase shift, some observables are unfavorably modified. A possible way to obtain a desired supersymmetric potential is proposed.
• Examination of the C 22 radius determination with interaction cross sections

  T. Nagahisa, W. Horiuchi

  Physical Review C 97 5 2018年05月23日 [査読有り][通常論文]
   

  A nuclear radius of C22 is investigated with the total reaction cross sections at medium- to high-incident energies in order to resolve the radius puzzle in which two recent interaction cross-section measurements using H1 and C12 targets show the quite different radii. The cross sections of C22 are calculated consistently for these target nuclei within a reliable microscopic framework, the Glauber theory. To describe appropriately such a reaction involving a spatially extended nucleus, the multiple scattering processes within the Glauber theory are fully taken into account, that is, the multidimensional integration in the Glauber amplitude is evaluated using a Monte Carlo technique without recourse to the optical-limit approximation. We discuss the sensitivity of the spatially extended halo tail to the total reaction cross sections. The root-mean-square matter radius obtained in this study is consistent with that extracted from the recent cross-section measurement on C12 target. We show that the simultaneous reproduction of the two recent measured cross sections is not feasible within this framework.
• Nuclear surface diffuseness revealed in nucleon-nucleus diffraction

  S. Hatakeyama, W. Horiuchi, A. Kohama

  Physical Review C 97 5 2018年05月18日 [査読有り][通常論文]
   

  The nuclear surface provides useful information on nuclear radius, nuclear structure, as well as properties of nuclear matter. We discuss the relationship between the nuclear surface diffuseness and elastic scattering differential cross section at the first diffraction peak of high-energy nucleon-nucleus scattering as an efficient tool in order to extract the nuclear surface information from limited experimental data involving short-lived unstable nuclei. The high-energy reaction is described by a reliable microscopic reaction theory, the Glauber model. Extending the idea of the black sphere model, we find one-to-one correspondence between the nuclear bulk structure information and proton-nucleus elastic scattering diffraction peak. This implies that we can extract both the nuclear radius and diffuseness simultaneously, using the position of the first diffraction peak and its magnitude of the elastic scattering differential cross section. We confirm the reliability of this approach by using realistic density distributions obtained by a mean-field model.
• Constraining the (K)over-barN interaction from the 1S level shift of kaonic deuterium

  Tsubasa Hoshino, Shota Ohnishi, Wataru Horiuchi, Tetsuo Hyodo, Wolfram Weise

  PHYSICAL REVIEW C 96 4 2017年10月 [査読有り][通常論文]
   

  Motivated by the precise measurement of the 1S level shift of kaonic hydrogen, we perform accurate three-body calculations for the spectrum of kaonic deuterium using a realistic antikaon-nucleon ((K) over barN) interaction. In order to describe both short- and long-range behaviors of the kaonic atomic states, we solve the three-body Schrodinger equation with a superposition of a large number of correlated Gaussian basis functions covering distances up to several hundreds of fm. Transition energies between 1S, 2P, and 2S states are determined with high precision. The complex energy shift of the 1S level of kaonic deuterium is found to be Delta E - i Gamma/2 = (670 - i 508) eV. The sensitivity of this level shift with respect to the isospin I = 1 component of the (K) over barN interaction is examined. It is pointed out that an experimental determination of the kaonic deuterium level shift within an uncertainty of 25% will provide a constraint for the I = 1 component of the (K) over barN interaction significantly stronger than that from kaonic hydrogen.
• Neutron-skin thickness determines the surface tension of a compressible nuclear droplet

  W. Horiuchi, S. Ebata, K. Iida

  PHYSICAL REVIEW C 96 3 2017年09月 [査読有り][通常論文]
   

  We systematically investigate the neutron-skin thickness of neutron-rich nuclei within a compressible droplet model, which includes several parameters characterizing the surface tension and the equation of state (EOS) of asymmetric nuclear matter as well as corrections due to the surface diffuseness. Such a systematic analysis helps towards constraining the EOS parameters of asymmetric nuclear matter and the poorly known density dependence of the surface tension; the latter is estimated with help of available experimental data for the neutron and proton density distributions and the nuclear masses. Validity of the present approach is confirmed by calculating realistic density distributions of Ca, Ni, Zr, Sn, Yb, and Pb isotopes within a microscopic Skyrme-Hartree-Fock+BCS method for various sets of the effective nuclear force. Our macroscopic model accompanied by the diffuseness corrections works well in the sense that it well reproduces the evolution of the microscopically deduced neutron-skin thickness with respect to the neutron number for selected sets of the effective nuclear force. We find that the surface tension of the compressible nuclear droplet is a key to bridging a gap between microscopic and macroscopic approaches.
• Clustering in Light Nuclei with the Correlated Gaussian Approach

  Suzuki Yasuyuki, Horiuchi Wataru

  Emergent Phenomena in Atomic Nuclei from Large Scale Modeling: A Symmetry-Guided Perspective 199 - 227 2017年08月 [査読有り][招待有り]
  
• Low-lying electric-dipole strengths of Ca, Ni, and Sn isotopes imprinted on total reaction cross sections

  W. Horiuchi, S. Hatakeyama, S. Ebata, Y. Suzuki

  PHYSICAL REVIEW C 96 2 2017年08月 [査読有り][通常論文]
   

  Low-lying electric-dipole (E1) strength of a neutron-rich nucleus contains information on neutron-skin thickness, deformation, and shell evolution. We discuss the possibility of making use of total reaction cross sections on Ca-40, Sn-120, and Pb-208 targets to probe the E1 strength of neutron-rich Ca, Ni, and Sn isotopes. They exhibit large enhancement of the E1 strength at neutron number N > 28, 50, and 82, respectively, due to a change of the single-particle orbits near the Fermi surface participating in the transitions. The density distributions and the electric-multipole strength functions of those isotopes are calculated by the Hartree-Fock+BCS and the canonical-basis-time-dependent-Hartree-Fock-Bogoliubov methods, respectively, using three kinds of Skyrme-type effective interaction. The nuclear and Coulomb breakup processes are respectively described with the Glauber model and the equivalent photon method in which the effect of finite-charge distribution is taken into account. The three Skyrme interactions give different results for the total reaction cross sections because of different Coulomb breakup contributions. The contribution of the low-lying E1 strength is amplified when the low-incident energy is chosen. With an appropriate choice of the incident energy and target nucleus, the total reaction cross section can be complementary to the Coulomb excitation for analyzing the low-lying E1 strength of unstable nuclei.
• Few-body approach to the structure of K̄-nuclear quasibound states FEW-BODY APPROACH to the STRUCTURE of K̄-.. OHNISHI, HORIUCHI, HOSHINO, MIYAHARA, and HYODO

  Shota Ohnishi, Wataru Horiuchi, Tsubasa Hoshino, Kenta Miyahara, Tetsuo Hyodo

  Physical Review C 95 6 2017年06月06日 [査読有り][通常論文]
   

  The structure of light antikaon-nuclear quasibound states, which consist of an antikaon (K̄=K-,K̄0) and a few nucleons (N=p,n), such as K̄NN, K̄NNN, K̄NNNN, and K̄NNNNNN systems, is studied with full three-to seven-body calculations. Employing a realistic K̄N potential based on the chiral SU(3) effective field theory with the SIDDHARTA constraint, we show that the central nucleon densities of these systems increase when the antikaon is injected, by about factor of 2 at maximum. The K̄NNNN system shows the largest central density, about 0.74 fm-3 even with the phenomenological K̄N potential, which is not as high as those suggested in previous studies with approximate treatments of the few-body systems. We find that the spin of the ground state of the K̄NNNNNN system depends on the strength of the K̄N attraction. Thus, the quantum number of the ground state can be another constraint on the K̄N interaction.
• Few-body approach to the structure of (K)over-bar-nuclear quasibound states

  Shota Ohnishi, Wataru Horiuchi, Tsubasa Hoshino, Kenta Miyahara, Tetsuo Hyodo

  PHYSICAL REVIEW C 95 6 2017年06月 [査読有り][通常論文]
   

  The structure of light antikaon-nuclear quasibound states, which consist of an antikaon ((K) over barK= K-,(K) over bar (0)) and a few nucleons (N = p, n), such as (K) over bar NN, (K) over bar NNN, (K) over bar NNNN, and (K) over bar NNNNNN systems, is studied with full three- to seven-body calculations. Employing a realistic (K) over barN potential based on the chiral SU(3) effective field theory with the SIDDHARTA constraint, we show that the central nucleon densities of these systems increase when the antikaon is injected, by about factor of 2 at maximum. The (K) over bar NNNN system shows the largest central density, about 0.74 fm(-3) even with the phenomenological (K) over barN potential, which is not as high as those suggested in previous studies with approximate treatments of the few-body systems. We find that the spin of the ground state of the (K) over bar NNNNNN system depends on the strength of the (K) over barN attraction. Thus, the quantum number of the ground state can be another constraint on the (K) over barN interaction.
• Towards a unified model of neutrino-nucleus reactions for neutrino oscillation experiments

  S. X. Nakamura, H. Kamano, Y. Hayato, M. Hirai, W. Horiuchi, S. Kumano, T. Murata, K. Saito, M. Sakuda, T. Sato, Y. Suzuki

  REPORTS ON PROGRESS IN PHYSICS 80 5 2017年05月 [査読有り][招待有り]
   

  A precise description of neutrino-nucleus reactions will play a key role in addressing fundamental questions such as the leptonic CP violation and the neutrino mass hierarchy through analyzing data from next-generation neutrino oscillation experiments. The neutrino energy relevant to the neutrino-nucleus reactions spans a broad range and, accordingly, the dominant reaction mechanism varies across the energy region from quasi-elastic scattering through nucleon resonance excitations to deep inelastic scattering. This corresponds to transitions of the effective degree of freedom for theoretical description from nucleons through meson-baryon to quarks. The main purpose of this review is to report our recent efforts towards a unified description of the neutrino-nucleus reactions over the wide energy range; recent overall progress in the field is also sketched. Starting with an overview of the current status of neutrino-nucleus scattering experiments, we formulate the cross section to be commonly used for the reactions over all the energy regions. A description of the neutrino-nucleon reactions follows and, in particular, a dynamical coupled-channels model for meson productions in and beyond the Delta(1232) region is discussed in detail. We then discuss the neutrino-nucleus reactions, putting emphasis on our theoretical approaches. We start the discussion with electroweak processes in few-nucleon systems studied with the correlated Gaussian method. Then we describe quasi-elastic scattering with nuclear spectral functions, and meson productions with a Delta-hole model. Nuclear modifications of the parton distribution functions determined through a global analysis are also discussed. Finally, we discuss issues to be addressed for future developments.
• Correlated-Gaussian approach to linear-chain states: Case of four alpha particles

  Y. Suzuki, W. Horiuchi

  PHYSICAL REVIEW C 95 4 2017年04月 [査読有り][通常論文]
   

  We show that correlated Gaussians with good angular momentum and parity provide flexible basis functions for specific elongated shape. As an application we study linear-chain states of four a particles in variation-after-projection calculations in which all the matrix elements are evaluated analytically. We find possible chain states for J(pi) = 0(+), 2(+), 4(+) and perhaps 6(+) with the bandhead energy being about 33 MeV from the ground state of O-16. No chain states with J >= 8 are found. The nature of the rotational sequence of the chain states is clarified in contrast to a rigid-body rotation. The quadrupole deformation parameters estimated from the chain states increase from 0.59 to 1.07 for 2(+) to 6(+). This work suggests undeveloped fields for the correlated Gaussians beyond those problems which have hitherto been solved successfully.
• Proton Distribution Radii of C12-19 Illuminate Features of Neutron Halos

  R. Kanungo, W. Horiuchi, G. Hagen, G. R. Jansen, P. Navratil, F. Ameil, J. Atkinson, Y. Ayyad, D. Cortina-Gil, I. Dillmann, A. Estrade, A. Evdokimov, F. Farinon, H. Geissel, G. Guastalla, R. Janik, M. Kimura, R. Knoebel, J. Kurcewicz, Yu. A. Litvinov, M. Marta, M. Mostazo, I. Mukha, C. Nociforo, H. J. Ong, S. Pietri, A. Prochazka, C. Scheidenberger, B. Sitar, P. Strmen, Y. Suzuki, M. Takechi, J. Tanaka, I. Tanihata, S. Terashima, J. Vargas, H. Weick, J. S. Winfield

  PHYSICAL REVIEW LETTERS 117 10 6  2016年09月 [査読有り][通常論文]
   

  Proton radii of C12-19 densities derived from first accurate charge changing cross section measurements at 900A MeV with a carbon target are reported. A thick neutron surface evolves from similar to 0.5 fm in C-15 to similar to 1 fm in C-19. The halo radius in C-19 is found to be 6.4 +/- 0.7 fm as large as Li-11. Ab initio calculations based on chiral nucleon-nucleon and three-nucleon forces reproduce the radii well.
• Parameter-free calculation of charge-changing cross sections at high energy

  Y. Suzuki, W. Horiuchi, S. Terashima, R. Kanungo, F. Ameil, J. Atkinson, Y. Ayyad, D. Cortina-Gil, I. Dillmann, A. Estrade, A. Evdokimov, F. Farinon, H. Geissel, G. Guastalla, R. Janik, R. Knoebel, J. Kurcewicz, Yu. A. Litvinov, M. Marta, M. Mostazo, I. Mukha, C. Nociforo, H. J. Ong, S. Pietri, A. Prochazka, C. Scheidenberger, B. Sitar, P. Strmen, M. Takechi, J. Tanaka, I. Tanihata, J. Vargas, H. Weick, J. S. Winfield

  PHYSICAL REVIEW C 94 1 5  2016年07月 [査読有り][通常論文]
   

  Charge-changing cross sections at high energies are expected to provide useful information on nuclear charge radii. No reliable theory to calculate the cross section has yet been available. We develop a formula using Glauber and eikonal approximations and test its validity with recent new data on carbon isotopes measured at around 900A MeV. We first confirm that our theory reproduces the cross sections of C-12,C-13,C-14+C-12 consistently with the known charge radii. Next we show that the cross sections of C12-19 on a proton target are all well reproduced provided the role of neutrons is accounted for. We also discuss the energy dependence of the charge-changing cross sections.
• He-3(alpha, gamma)Be-7 and H-3(alpha, gamma)Li-7 astrophysical S factors from the no-core shell model with continuum

  Jeremy Dohet-Eraly, Petr Navratil, Sofia Quaglioni, Wataru Horiuchi, Guillaume Hupin, Francesco Raimondi

  PHYSICS LETTERS B 757 430 - 436 2016年06月 [査読有り][通常論文]
   

  The He-3(alpha, gamma)Be-7 and H-3(alpha, gamma)Li-7 astrophysical S factors are calculated within the no-core shell model with continuum using a renormalized chiral nucleon-nucleon interaction. The He-3(alpha, gamma)Be-7 astrophysical S factors agree reasonably well with the experimental data while the H-3(alpha, gamma)Li-7 ones are overestimated. The seven-nucleon bound and resonance states and the alpha + He-3/H-3 elastic scattering are also studied and compared with experiment. The low-lying resonance properties are rather well reproduced by our approach. At low energies, the s-wave phase shift, which is non-resonant, is overestimated. (C) 2016 The Authors and Lawrence Livermore National Laboratory. Published by Elsevier B.V.
• Extracting nuclear sizes of medium to heavy nuclei from total reaction cross sections

  W. Horiuchi, S. Hatakeyama, S. Ebata, Y. Suzuki

  PHYSICAL REVIEW C 93 4 16  2016年04月 [査読有り][通常論文]
   

  Background: Proton and neutron radii are fundamental quantities of atomic nuclei. To study the sizes of short-lived unstable nuclei, there is a need for an alternative to electron scattering. Purpose: The recent paper by Horiuchi et al. [Phys. Rev. C 89, 011601(R) (2014)] proposed a possible way of extracting the matter and neutron-skin thickness of light-to medium-mass nuclei using total reaction cross section, sigma(R). The analysis is extended to medium to heavy nuclei up to lead isotopes with due attention to Coulomb breakup contributions as well as density distributions improved by paring correlation. Methods: We formulate a quantitative calculation of sigma(R) based on the Glauber model including the Coulomb breakup. To substantiate the treatment of the Coulomb breakup, we also evaluate the Coulomb breakup cross section due to the electric dipole field in a canonical-basis-time-dependent-Hartree-Fock-Bogoliubov theory in the three-dimensional coordinate space. Results: We analyze sigma(R) 's of 103 nuclei with Z = 20, 28, 40, 50, 70, and 82 incident on light targets, (1,2) H, He-4, and (12) C. Three kinds of Skyrme interactions are tested to generate those wave functions. To discuss possible uncertainty due to the Coulomb breakup, we examine its dependence on the target, the incident energy, and the Skyrme interaction. The proton is a most promising target for extracting the nuclear sizes as the Coulomb excitation can safely be neglected. We find that the so-called reaction radius, sigma(R) = root sigma(R)/pi, for the proton target is very well approximated by a linear function of two variables, the matter radius and the skin thickness, in which three constants depend only on the incident energy. We quantify the accuracy of sigma(R) measurements needed to extract the nuclear sizes. Conclusions: The proton is the best target because, once the incident energy is set, its a(R) is very accurately determined by only the matter radius and neutron-skin thickness. If sigma(R) 's at different incident energies are measured, one can determine both the proton and neutron radii for unstable nuclei as well. The total reaction cross sections calculated in this paper are given as Supplemental Material for the sake of future measurements.
• Nonquenched Isoscalar Spin-M1 Excitations in sd-Shell Nuclei

  H. Matsubara, A. Tamii, H. Nakada, T. Adachi, J. Carter, M. Dozono, H. Fujita, K. Fujita, Y. Fujita, K. Hatanaka, W. Horiuchi, M. Itoh, T. Kawabata, S. Kuroita, Y. Maeda, P. Navratil, P. von Neumann-Cosel, R. Neveling, H. Okamura, L. Popescu, I. Poltoratska, A. Richter, B. Rubio, H. Sakaguchi, S. Sakaguchi, Y. Sakemi, Y. Sasamoto, Y. Shimbara, Y. Shimizu, F. D. Smit, K. Suda, Y. Tameshige, H. Tokieda, Y. Yamada, M. Yosoi, J. Zenihiro

  PHYSICAL REVIEW LETTERS 115 10 1 - 102501 2015年09月 [査読有り][通常論文]
   

  Differential cross sections of isoscalar and isovector spin-M1 (0(+) -> 1(+)) transitions are measured using high-energy-resolution proton inelastic scattering at E-p = 295 MeV on Mg-24, Si-28, S-32, and Ar-36 at 0 degrees-14 degrees. The squared spin-M1 nuclear transition matrix elements are deduced from the measured differential cross sections by applying empirically determined unit cross sections based on the assumption of isospin symmetry. The ratios of the squared nuclear matrix elements accumulated up to E-x = 16 MeV compared to a shell-model prediction are 1.01(9) for isoscalar and 0.61(6) for isovector spin-M1 transitions, respectively. Thus, no quenching is observed for isoscalar spin-M1 transitions, while the matrix elements for isovector spin-M1 transitions are quenched by an amount comparable with the analogous GamowTeller transitions on those target nuclei.
• Short-range correlations in nuclei with similarity renormalization group transformations

  T. Neff, H. Feldmeier, W. Horiuchi

  PHYSICAL REVIEW C 92 2 1 - 24003 2015年08月 [査読有り][通常論文]
   

  Background: Realistic nucleon-nucleon interactions induce short-range correlations in nuclei. To solve the many-body problem unitary transformations like the similarity renormalization group (SRG) are often used to soften the interactions. Purpose: Two-body densities can be used to illustrate how the SRG eliminates short-range correlations in the wave function. The short-range information can however be recovered by transforming the density operators. Method: The many-body problem is solved for He-4 in the no core shell model (NCSM) with SRG transformed AV8' and chiral N3LO interactions. The NCSM wave functions are used to calculate two-body densities with bare and SRG transformed density operators in two-body approximation. Results: The two-body momentum distributions for AV8' and N3LO have similar high-momentum components up to relative momenta of about 2.5 fm(-1), dominated by tensor correlations, but differ in their behavior at higher relative momenta. The contributions of many-body correlations are small for pairs with vanishing pair momentum but not negligible for the momentum distributions integrated over all pair momenta. Many-body correlations are induced by the strong tensor force and lead to a reshuffling of pairs between different spin-isospin channels. Conclusions: When using the SRG it is essential to use transformed operators for observables sensitive to short-range physics. Back-to-back pairs with vanishing pair momentum are the best tool to study short-range correlations.
• Proton radius of Be-14 from measurement of charge-changing cross sections

  S. Terashima, I. Tanihata, R. Kanungo, A. Estrade, W. Horiuchi, F. Ameil, J. Atkinson, Y. Ayyad, D. Cortina-Gil, I. Dillmann, A. Evdokimov, F. Farinon, H. Geissel, G. Guastalla, R. Janik, M. Kimura, R. Knoebel, J. Kurcewicz, Yu. A. Litvinov, M. Marta, M. Mostazo, I. Mukha, T. Neff, C. Nociforo, H. J. Ong, S. Pietri, A. Prochazka, C. Scheidenberger, B. Sitar, Y. Suzuki, M. Takechi, J. Tanaka, J. Vargas, J. S. Winfield, H. Weick

  PROGRESS OF THEORETICAL AND EXPERIMENTAL PHYSICS 2014 10 2  2014年10月 [査読有り][通常論文]
   

  The charge-changing cross sections of Be-7,Be-9-12,Be-14 have been measured at 900A MeV on a carbon target. These cross sections are discussed both in terms of a geometrical and a Glauber model. From several different analyses of the cross sections, the proton distribution radius (proton radius) of Be-14 is determined for the first time to be 2.41 +/- 0.04 fm. A large difference in the proton and neutron radii is found. The proton radii are compared to the results of fermionic molecular dynamics (FMD) and antisymmetrized molecular dynamics (AMD) calculations.
• Proton Radii of B12-17 Define a Thick Neutron Surface in B-17

  A. Estrade, R. Kanungo, W. Horiuchi, F. Ameil, J. Atkinson, Y. Ayyad, D. Cortina-Gil, I. Dillmann, A. Evdokimov, F. Farinon, H. Geissel, G. Guastalla, R. Janik, M. Kimura, R. Knoebel, J. Kurcewicz, Yu. A. Litvinov, M. Marta, M. Mostazo, I. Mukha, C. Nociforo, H. J. Ong, S. Pietri, A. Prochazka, C. Scheidenberger, B. Sitar, P. Strmen, Y. Suzuki, M. Takechi, J. Tanaka, I. Tanihata, S. Terashima, J. Vargas, H. Weick, J. S. Winfield

  PHYSICAL REVIEW LETTERS 113 13 2014年09月 [査読有り][通常論文]
   

  The first determination of radii of point proton distribution (proton radii) of B12-17 from charge-changing cross sections (sigma(CC)) measurements at the FRS, GSI, Darmstadt is reported. The proton radii are deduced from a finite-range Glauber model analysis of the sCC. The radii show an increase from B-13 to B-17 and are consistent with predictions from the antisymmetrized molecular dynamics model for the neutron-rich nuclei. The measurements show the existence of a thick neutron surface with neutron-proton radius difference of 0.51(0.11) fm in B-17.
• Harmonic-oscillator excitations of precise few-body wave functions

  W. Horiuchi, Y. Suzuki

  PHYSICAL REVIEW C 90 3 1 - 34001 2014年09月 [査読有り][通常論文]
   

  A method for calculating the occupation probability of the number of harmonic-oscillator (HO) quanta is developed for a precise few-body wave function obtained in a correlated Gaussian basis. The probability distributions of two- to four-nucleon wave functions obtained by using different nucleon-nucleon (NN) interactions are analyzed to gain insight into the characteristic behavior of the various interactions. Tensor correlations as well as short-range correlations play a crucial role in enhancing the probability of high HO excitations. For the excited states of He-4, the interaction dependence is much less because high HO quanta are mainly responsible for describing the relative-motion function between the 3N + N (H-3 + p and He-3 + n) clusters.
• Mean-field analysis of ground-state and low-lying electric dipole strength in C-22

  T. Inakura, W. Horiuchi, Y. Suzuki, T. Nakatsukasa

  PHYSICAL REVIEW C 89 6 1 - 64316 2014年06月 [査読有り][通常論文]
   

  Properties of neutron-rich C-22 are studied using the mean-field approach with Skyrme energy density functionals. Its weak binding and large total reaction cross section, which are suggested by recent experiments, are simulated by modifying the central part of Skyrme potential. Calculating E1 strength distribution by using the random-phase approximation, we investigate developments of low-lying electric dipole ( E1) strength and the contribution of core excitations of C-20. As the neutron Fermi level approaches the zero-energy threshold (epsilon(F) greater than or similar to -1 MeV), we find that the low-lying E1 strength exceeds the energy-weighted cluster sum rule, which indicates the importance of core excitations with the 1d(5/2) orbit.
• Electric dipole response of He-6: Halo-neutron and core excitations

  D. Mikami, W. Horiuchi, Y. Suzuki

  PHYSICAL REVIEW C 89 6 1 - 64303 2014年06月 [査読有り][通常論文]
   

  Electric dipole (E1) response of He-6 is studied with a fully microscopic six-body calculation. The wave functions for the ground and excited states are expressed as a superposition of explicitly correlated Gaussians. Final state interactions of three-body decay channels are explicitly taken into account. The ground state properties and the low-energy E1 strength are obtained consistently with observations. Two main peaks as well as several small peaks are found in the E1 strength function. The peak at the high-energy region indicates a typical macroscopic picture of the giant dipole resonance, the out-of-phase proton-neutron motion. The transition densities of the lower-lying peaks exhibit in-phase proton-neutron motion in the internal region, out-of-phase motion near the surface region, and spatially extended neutron oscillation, indicating a soft-dipole mode and its vibrationally excited mode. The compressional dipole strength is also examined in relation to the soft-dipole mode.
• Tests of a Deformable Core Plus Few-Nucleon Model

  W. Horiuchi, Y. Suzuki

  FEW-BODY SYSTEMS 55 2 121 - 133 2014年02月 [査読有り][通常論文]
   

  We formulate a core plus few-nucleon model allowing for a rotational excitation of the core. Three and four-body systems including a C-12 core nucleus are studied using an explicitly correlated Gaussian basis. Effects of the core excitation are tested by investigating energy levels and electric quadrupole transition probabilities. Though some improvements are obtained, we realize that the Pauli principle for the nucleon-deformable core motion has to be appropriately defined for better understanding.
• Correlated-basis description of alpha-cluster and delocalized 0(+) states in O-16

  W. Horiuchi, Y. Suzuki

  PHYSICAL REVIEW C 89 1 1 - 11304 2014年01月 [査読有り][通常論文]
   

  A five-body calculation of C-12+ n + n + p + p is performed to take a step towards solving an outstanding problem in nuclear theory: the simultaneous and accurate description of the ground and first excited 0(+) states of O-16. The interactions between the constituent particles are chosen consistently with the energies of bound subsystems, especially C-12+ n, C-12+ p, and the alpha particle. The five-body dynamics is solved with the stochastic variational method on correlated Gaussian basis functions. No restriction is imposed on the four-nucleon configurations except for the Pauli principle excluding the occupied orbits in C-12. The energies of both the ground and first excited states of O-16 are obtained in excellent agreement with experiment. Analysis of the wave functions indicates a spatially localized alpha-particle-like cluster structure for the excited state and a shell-model-like delocalized structure for the ground state.
• Probing neutron-skin thickness with total reaction cross sections

  W. Horiuchi, Y. Suzuki, T. Inakura

  PHYSICAL REVIEW C 89 1 1 - 11601 2014年01月 [査読有り][通常論文]
   

  We analyze total reaction cross sections, sigma(R), to explore their sensitivity to the neutron-skin thickness of nuclei. We cover 91 nuclei of O, Ne, Mg, Si, S, Ca, and Ni isotopes. The cross sections are calculated in the Glauber theory using the density distributions obtained with the Skyrme-Hartree-Fock method in three-dimensional coordinate space. Defining a reaction radius, a(R) = root alpha(R)/pi, to characterize the nuclear size and target (proton or C-12) dependence, we find an empirical formula for expressing a(R) with the point matter radius and the skin thickness, and assess two practical ways of determining the skin thickness from proton-nucleus sigma(R) values measured at different energies or from sigma(R) values measured for different targets.
• Excited States and Strength Functions of He-4 in Correlated Gaussians

  W. Horiuchi, Y. Suzuki

  FEW-BODY SYSTEMS 54 12 2407 - 2418 2013年12月 [査読有り][通常論文]
   

  Resonances and continuum states of He-4 are studied using correlated Gaussians. Applicability of the square-integrable functions is tested with use of a complex scaling method. All the known levels of He-4 up to the excitation energy of 26 MeV are well understood with a realistic nucleon-nucleon potential. The importance of the tensor force is stressed. Strength functions for isoscalar monopole and spin-dipole tensor operators are investigated.
• Theory and application of explicitly correlated Gaussians

  Jim Mitroy, Sergiy Bubin, Wataru Horiuchi, Yasuyuki Suzuki, Ludwik Adamowicz, Wojciech Cencek, Krzysztof Szalewicz, Jacek Komasa, D. Blume, Kalman Varga

  REVIEWS OF MODERN PHYSICS 85 2 693 - 749 2013年05月 [査読有り][招待有り]
   

  The variational method complemented with the use of explicitly correlated Gaussian basis functions is one of the most powerful approaches currently used for calculating the properties of few-body systems. Despite its conceptual simplicity, the method offers great flexibility, high accuracy, and can be used to study diverse quantum systems, ranging from small atoms and molecules to light nuclei, hadrons, quantum dots, and Efimov systems. The basic theoretical foundations are discussed, recent advances in the applications of explicitly correlated Gaussians in physics and chemistry are reviewed, and the strengths and weaknesses of the explicitly correlated Gaussians approach are compared with other few-body techniques.
• Spin-dipole strength functions of 4He with realistic nuclear forces

  W. Horiuchi, Y. Suzuki

  Physical Review C - Nuclear Physics 87 3 1 - 34001 2013年03月11日 [査読有り][通常論文]
   

  Both isoscalar and isovector spin-dipole excitations of 4He are studied using realistic nuclear forces in the complex scaling method. The ground state of 4He and discretized continuum states with Jπ=0-,1 -,2- for A=4 nuclei are described in explicitly correlated Gaussians reinforced with global vectors for angular motion. Two- and three-body decay channels are specifically treated to take into account final state interactions. The observed resonance energies and widths of the negative-parity levels are all in fair agreement with those calculated from both the spin-dipole and electric-dipole strength functions as well as the energy eigenvalues of the complex scaled Hamiltonian. Spin-dipole sum rules, both non-energy-weighted and energy-weighted, are discussed in relation to tensor correlations in the ground state of 4He. © 2013 American Physical Society.
• Glauber-model analysis of total reaction cross sections for Ne, Mg, Si, and S isotopes with Skyrme-Hartree-Fock densities

  W. Horiuchi, T. Inakura, T. Nakatsukasa, Y. Suzuki

  PHYSICAL REVIEW C 86 2 1 - 24614 2012年08月 [査読有り][通常論文]
   

  A systematic analysis is made on the total reaction cross sections for Ne, Mg, Si, and S isotopes. The high-energy nucleus-nucleus collision is described based on the Glauber model. Using the Skyrme-Hartree-Fock method in the three-dimensional grid-space representation, we determine the nuclear density distribution for a wide range of nuclei self-consistently without assuming any spatial symmetry. The calculated total reaction cross sections consistently agree with the recent cross section data on the Ne+C-12 collision at 240 AMeV, which makes it possible to discuss the radius and deformation of the isotopes. The total reaction cross sections for Mg+C-12, Si+C-12, and S+C-12 cases are predicted for future measurements. We also find that the high-energy cross section data for O, Ne, and Mg isotopes on a C-12 target at around 1000 AMeV can not be reproduced consistently with the corresponding data at 240 AMeV.
• Ab initio study of the photoabsorption of 4He

  W. Horiuchi, Y. Suzuki, K. Arai

  Physical Review C - Nuclear Physics 85 5 2012年05月03日 [査読有り][通常論文]
   

  There are some discrepancies in the low-energy data on the photoabsorption cross section of 4He. We calculate the cross section with realistic nuclear forces and explicitly correlated Gaussian functions. Final-state interactions and two- and three-body decay channels are taken into account. The cross section is evaluated using two methods: With the complex scaling method the total absorption cross section is obtained up to the rest energy of a pion, and with the microscopic R-matrix method cross sections for both 4He(γ,p)3H and 4He(γ,n)3He are calculated below 40 MeV. Both methods give virtually the same result. The cross section rises sharply from the 3H+p threshold, reaching a giant resonance peak at 26-27 MeV. Our calculation reproduces almost all the data above 30 MeV. We stress the importance of 3H+p and 3He+n cluster configurations on the cross section as well as the effect of the one-pion exchange potential on the photonuclear sum rule. © 2012 American Physical Society.
• Ab initio study of the photoabsorption of He-4

  W. Horiuchi, Y. Suzuki, K. Arai

  PHYSICAL REVIEW C 85 5 1 - 54002 2012年05月 [査読有り][通常論文]
   

  There are some discrepancies in the low-energy data on the photoabsorption cross section of He-4. We calculate the cross section with realistic nuclear forces and explicitly correlated Gaussian functions. Final-state interactions and two-and three-body decay channels are taken into account. The cross section is evaluated using two methods: With the complex scaling method the total absorption cross section is obtained up to the rest energy of a pion, and with the microscopic R-matrix method cross sections for both He-4(gamma, p)H-3 and He-4(gamma, n)He-3 are calculated below 40 MeV. Both methods give virtually the same result. The cross section rises sharply from the H-3 + p threshold, reaching a giant resonance peak at 26-27 MeV. Our calculation reproduces almost all the data above 30 MeV. We stress the importance of H-3 + p and He-3 + n cluster configurations on the cross section as well as the effect of the one-pion exchange potential on the photonuclear sum rule.
• Global optical potential for nucleus-nucleus systems from 50 MeV/u to 400 MeV/u

  T. Furumoto, W. Horiuchi, M. Takashina, Y. Yamamoto, Y. Sakuragi

  Physical Review C - Nuclear Physics 85 4 2012年04月10日 [査読有り][通常論文]
   

  We present a new global optical potential (GOP) for nucleus-nucleus systems, including neutron-rich and proton-rich isotopes, in the energy range of 50-400 MeV/u. The GOP is derived from the microscopic folding model with the complex G-matrix interaction CEG07 and the global density presented by the São Paulo group. The folding model accounts for realistic complex optical potentials of nucleus-nucleus systems well and reproduces the existing elastic scattering data for stable heavy-ion projectiles at incident energies above 50 MeV/u. We then calculate the folding-model potentials (FMPs) for projectiles of even-even isotopes, 8-22C, 12-24O, 16-38Ne, 20-40Mg, 22-48Si, 26-52S, 30-62Ar, and 34-70Ca, scattered by stable target nuclei of 12C, 16O, 28Si, 40Ca 58Ni, 90Zr, 120Sn, and 208Pb at incident energies of 50, 60, 70, 80, 100, 120, 140, 160, 180, 200, 250, 300, 350, and 400 MeV/u. The calculated FMP is represented, with a sufficient accuracy, by a linear combination of 10-range Gaussian functions. The expansion coefficients depend on the incident energy, the projectile and target mass numbers, and the projectile atomic number, while the range parameters depend only on the projectile and target mass numbers. The adequate mass region of the present GOP by the global density is inspected in comparison with FMP by realistic density. The full set of the range parameters and the coefficients for all the projectile-target combinations at each incident energy are provided on a permanent open-access website together with a fortran program for calculating the microscopic-basis GOP (MGOP) for a desired projectile nucleus by the spline interpolation over the incident energy and the target mass number. © 2012 American Physical Society.
• Global optical potential for nucleus-nucleus systems from 50 MeV/u to 400 MeV/u

  T. Furumoto, W. Horiuchi, M. Takashina, Y. Yamamoto, Y. Sakuragi

  PHYSICAL REVIEW C 85 4 1 - 44607 2012年04月 [査読有り][通常論文]
   

  We present a new global optical potential (GOP) for nucleus-nucleus systems, including neutron-rich and proton-rich isotopes, in the energy range of 50-400 MeV/u. The GOP is derived from the microscopic folding model with the complex G-matrix interaction CEG07 and the global density presented by the Sao Paulo group. The folding model accounts for realistic complex optical potentials of nucleus-nucleus systems well and reproduces the existing elastic scattering data for stable heavy-ion projectiles at incident energies above 50 MeV/u. We then calculate the folding-model potentials (FMPs) for projectiles of even-even isotopes, C8-22, O12-24, Ne16-38, Mg20-40, Si22-48, S26-52, Ar30-62, and Ca34-70, scattered by stable target nuclei of C-12, O-16, Si-28, Ca-40 Ni-58, Zr-90, Sn-120, and Pb-208 at incident energies of 50, 60, 70, 80, 100, 120, 140, 160, 180, 200, 250, 300, 350, and 400 MeV/u. The calculated FMP is represented, with a sufficient accuracy, by a linear combination of 10-range Gaussian functions. The expansion coefficients depend on the incident energy, the projectile and target mass numbers, and the projectile atomic number, while the range parameters depend only on the projectile and target mass numbers. The adequate mass region of the present GOP by the global density is inspected in comparison with FMP by realistic density. The full set of the range parameters and the coefficients for all the projectile-target combinations at each incident energy are provided on a permanent open-access website together with a FORTRAN program for calculating the microscopic-basis GOP (MGOP) for a desired projectile nucleus by the spline interpolation over the incident energy and the target mass number.
• Exploring the anomaly in the interaction cross section and matter radius of 23O

  R. Kanungo, A. Prochazka, M. Uchida, W. Horiuchi, G. Hagen, T. Papenbrock, C. Nociforo, T. Aumann, D. Boutin, D. Cortina-Gil, B. Davids, M. Diakaki, F. Farinon, H. Geissel, R. Gernhäuser, J. Gerl, R. Janik, Jensen, B. Jonson, B. Kindler, R. Knöbel, R. Krücken, M. Lantz, H. Lenske, Y. Litvinov, B. Lommel, K. Mahata, P. Maierbeck, A. Musumarra, T. Nilsson, C. Perro, C. Scheidenberger, B. Sitar, P. Strmen, B. Sun, Y. Suzuki, I. Szarka, I. Tanihata, H. Weick, M. Winkler

  Physical Review C - Nuclear Physics 84 6 2011年12月21日 [査読有り][通常論文]
   

  New measurements of the interaction cross sections of 22,23O at 900A MeV performed at the GSI, Darmstadt are reported that address the unsolved puzzle of the large cross section previously observed for 23O. The matter radii for these oxygen isotopes extracted through a Glauber model analysis are in good agreement with the new predictions of the ab initio coupled-cluster theory reported here. They are consistent with a 22O+neutron description of 23O as well. © 2011 American Physical Society.
• Exploring the anomaly in the interaction cross section and matter radius of O-23

  R. Kanungo, A. Prochazka, M. Uchida, W. Horiuchi, G. Hagen, T. Papenbrock, C. Nociforo, T. Aumann, D. Boutin, D. Cortina-Gil, B. Davids, M. Diakaki, F. Farinon, H. Geissel, R. Gernhaeuser, J. Gerl, R. Janik, O. Jensen, B. Jonson, B. Kindler, R. Knoebel, R. Kruecken, M. Lantz, H. Lenske, Y. Litvinov, B. Lommel, K. Mahata, P. Maierbeck, A. Musumarra, T. Nilsson, C. Perro, C. Scheidenberger, B. Sitar, P. Strmen, B. Sun, Y. Suzuki, I. Szarka, I. Tanihata, H. Weick, M. Winkler

  PHYSICAL REVIEW C 84 6 1 - 61304 2011年12月 [査読有り][通常論文]
   

  New measurements of the interaction cross sections of O-22,O-23 at 900A MeV performed at the GSI, Darmstadt are reported that address the unsolved puzzle of the large cross section previously observed for O-23. The matter radii for these oxygen isotopes extracted through a Glauber model analysis are in good agreement with the new predictions of the ab initio coupled-cluster theory reported here. They are consistent with a O-22 + neutron description of O-23 as well.
• Universality of short-range nucleon-nucleon correlations

  H. Feldmeier, W. Horiuchi, T. Neff, Y. Suzuki

  Physical Review C - Nuclear Physics 84 5 2011年11月09日 [査読有り][通常論文]
   

  Short-range correlations between nucleon pairs in different spin-isospin channels are investigated for light nuclei using the Argonne v8 ′ interaction. At distances below 1 fm a universal behavior is found for the deuteron, 3H, 3He, and for ground and first excited states in 4He. This behavior in coordinate space is reflected by a universal behavior for the high-momentum components in momentum space. The universality indicates that a pairwise renormalization is possible in order to obtain a universal effective two-body interaction that does not scatter to high-momentum states. The exact two-body densities are compared with those obtained using the unitary correlation operator method with simple trial wave functions. The effect of three-body correlations due to the tensor force on the two-body densities is discussed. © 2011 American Physical Society.
• Universality of short-range nucleon-nucleon correlations

  H. Feldmeier, W. Horiuchi, T. Neff, Y. Suzuki

  PHYSICAL REVIEW C 84 5 1 - 54003 2011年11月 [査読有り][通常論文]
   

  Short-range correlations between nucleon pairs in different spin-isospin channels are investigated for light nuclei using the Argonne v8' interaction. At distances below 1 fm a universal behavior is found for the deuteron, H-3, He-3, and for ground and first excited states in He-4. This behavior in coordinate space is reflected by a universal behavior for the high-momentum components in momentum space. The universality indicates that a pairwise renormalization is possible in order to obtain a universal effective two-body interaction that does not scatter to high-momentum states. The exact two-body densities are compared with those obtained using the unitary correlation operator method with simple trial wave functions. The effect of three-body correlations due to the tensor force on the two-body densities is discussed.
• Tests of the discretized-continuum method in three-body dipole strengths

  E. C. Pinilla, D. Baye, P. Descouvemont, W. Horiuchi, Y. Suzuki

  NUCLEAR PHYSICS A 865 1 43 - 56 2011年08月 [査読有り][通常論文]
   

  We investigate the (6)He dipole distribution in a three-body alpha + n + n model. Two approaches are used to describe the three-body 1(-) continuum: the discretized-continuum method, where the scattering wave functions are approximated by square-integrable functions, and the R-matrix formalism, where their asymptotic behaviour is taken into account. We show that some ambiguity exists in the pseudostate method. owing to the smoothing technique. necessary to derive continuous distributions. We show evidence for the important role of the halo structure in the E1 dipole strength. We also address the treatment of Pauli forbidden states in the three-body wave functions. (C) 2011 Elsevier By. All rights reserved.
• Matter radii of Mg32-35

  R. Kanungo, A. Prochazka, W. Horiuchi, C. Nociforo, T. Aumann, D. Boutin, D. Cortina-Gil, B. Davids, M. Diakaki, F. Farinon, H. Geissel, R. Gernhaeuser, J. Gerl, R. Janik, B. Jonson, B. Kindler, R. Knoebel, R. Kruecken, M. Lantz, H. Lenske, Y. Litvinov, B. Lommel, K. Mahata, P. Maierbeck, A. Musumarra, T. Nilsson, C. Perro, C. Scheidenberger, B. Sitar, P. Strmen, B. Sun, Y. Suzuki, I. Szarka, I. Tanihata, Y. Utsuno, H. Weick, M. Winkler

  PHYSICAL REVIEW C 83 2 1 - 21302 2011年02月 [査読有り][通常論文]
   

  The interaction cross sections of Mg32-35 at 900A MeV have been measurmed using the fragment separator at GSI. The deviation from the r(0)A(1/3) trend is slightly larger for Mg-35, signaling the possible formation of a longer tail in the neutron distribution for Mg-35. The radii extracted from a Glauber model analysis with Fermi densities are consistent with models predicting the development of neutron skins.
• Green's Function Method for Strength Function in Three-Body Continuum

  Yasuyuki Suzuki, Wataru Horiuchi, Daniel Baye

  PROGRESS OF THEORETICAL PHYSICS 123 3 547 - 568 2010年03月 [査読有り][通常論文]
   

  Practical methods to compute dipole strengths for a three-body system by using a discretized continuum are analyzed. New techniques involving Green's function are developed, either by correcting the tail of the approximate wave function in a direct calculation of the strength function or by using a solution of a driven Schrodinger equation in a summed expression of the strength. They are compared with the complex scaling method and the Lorentz integral transform, also making use of a discretized continuum. Numerical tests are performed with a hyperscalar three-body potential in the hyperspherical-harmonics formalism. They show that the Lorentz integral transform method is less practical than the other methods because of a difficult inverse transform. These other methods provide in general comparable accuracies.
• Probing the weakly-bound neutron orbit of Ne-31 with total reaction and one-neutron removal cross sections

  W. Horiuchi, Y. Suzuki, P. Capel, D. Baye

  PHYSICAL REVIEW C 81 2 1 - 24606 2010年02月 [査読有り][通常論文]
   

  A candidate of a neutron-halo nucleus, Ne-31, contains a single neutron in the pf shell. Within the Glauber and eikonal models, we analyze reactions used to study Ne-31. We show in a Ne-30 + n model that the magnitudes of the total reaction and above all of the one-neutron removal cross sections of Ne-31 on C-12 and Pb-208 targets strongly depend on the orbital angular momentum of the neutron, thereby providing us with efficient ways to determine both the spin-parity and structure of the ground state of Ne-31. Besides these inclusive observables, we also calculate energy and parallel-momentum distributions for the breakup of Ne-31 and show their strong dependence on the orbital of the valence neutron in the bound state of Ne-31.
• Phase-shift calculation using continuum-discretized states

  Y. Suzuki, W. Horiuchi, K. Arai

  NUCLEAR PHYSICS A 823 1-4 1 - 15 2009年05月 [査読有り][通常論文]
   

  We present a method for calculating scattering phase shifts which utilizes continuum-discretized states obtained in a bound-state type calculation. The wrong asymptotic behavior of the discretized state is remedied by means of the Green's function formalism. Test examples confirm the accuracy of the method. The alpha + n scattering is described using realistic nucleon-nucleon potentials. The 3/2(-) and 1/2(-) phase shifts obtained in a single-channel calculation are too small in comparison with experiment. The 1/2(+) phase shifts are in reasonable agreement with experiment, and gain contributions both from the tensor and central components of the nucleon-nucleon potential. (C) 2009 Elsevier B.V. All rights reserved.
• Elastic and Total Reaction Cross Sections of Oxygen Isotopes in Glauber Theory

  Badawy Abu-Ibrahim, Shohei Iwasaki, Wataru Horiuchi, Akihisa Kohama, Yasuyuki Suzuki

  JOURNAL OF THE PHYSICAL SOCIETY OF JAPAN 78 4 1 - 44201 2009年04月 [査読有り][通常論文]
   

  We systematically calculate the total reaction cross sections of oxygen isotopes, O15-24 on a C-12 target at high energies using the Glauber theory. The oxygen isotopes are described with Slater determinants generated from a phenomenological mean-field potential. The agreement between theoretical and experimental results is generally good, but a sharp increase of the reaction cross sections from O-21 to O-23 remains unresolved. To examine the sensitivity of the diffraction pattern of elastic scattering to the nuclear surface, we study the differential elastic-scattering cross sections of proton-O-20.21.23 at the incident energy of 300 MeV by calculating the full Glauber amplitude.
• Significance and properties of internucleon correlation functions

  Y. Suzuki, W. Horiuchi

  NUCLEAR PHYSICS A 818 3-4 188 - 207 2009年03月 [査読有り][通常論文]
   

  We show that a nuclear Hamiltonian and a set of internucleon correlation functions is in a one-to-one correspondence. The correlation functions for s-shell nuclei interacting via the two-nucleon interaction of AV8 type are calculated to exhibit the importance of tensor correlations as well as short-range central correlation. The asymptotic behavior of the correlation functions is also discussed. (C) 2009 Elsevier B.V. All rights reserved.
• Inversion doublets of 3N+N cluster structure in excited states of (4)He

  W. Horiuchi, Y. Suzuki

  PHYSICAL REVIEW C 78 3 1 - 34305 2008年09月 [査読有り][通常論文]
   

  Excited states of (4)He are studied in four-body calculations with explicitly correlated Gaussian bases. All the levels below E(x) = 26 MeV are reproduced reasonably well using realistic potentials. An analysis is made to show how the 0(2)(+) state becomes a resonance but those having almost the same structure as this state in different spin-isospin channels are not observed as resonances. The role of tensor force is stressed with a particular attention to the level spacing between the two 0(-) states. The calculation of spectroscopic amplitudes, nucleon decay widths, and spin-dipole transition strengths demonstrates that the 0(2)(+) state and the three lowest-lying negative-parity states with 0(-) and 2(-) have (3)H + p and (3)He + n cluster configurations, leading to the interpretation that these negative-parity states are the inversion-doublet partners of the 0(2)(+) state.
• Global-vector representation of the angular motion of few-particle systems II

  Y. Suzuki, W. Horiuchi, M. Orabi, K. Arai

  FEW-BODY SYSTEMS 42 1-4 33 - 72 2008年07月 [査読有り][通常論文]
   

  The angular motion of a few-body system is described with global vectors which depend on the positions of the particles. The previous study using a single global vector is extended to make it possible to describe both natural and unnatural parity states. Numerical examples include three- and four-nucleon systems interacting via nucleon-nucleon potentials of AV8 type and a 3 alpha system with a nonlocal alpha alpha potential. The results using the explicitly correlated Gaussian basis with the global vectors are shown to be in good agreement with those of other methods. A unique role of the unnatural parity component, caused by the tensor force, is clarified in the 0(1)(-) state of He-4. The two-particle correlation function is calculated in the coordinate and momentum spaces to show different characteristics of the interactions employed.
• Two-nucleon momentum distribution and correlation in A=6 systems

  W. Horiuchi, Y. Suzuki

  Journal of Physics: Conference Series 111 1 2008年05月01日 [査読有り][通常論文]
   

  The momentum distribution reflects the two-nucleon correlation in nuclei. The momentum distribution for the valence nucleons is calculated for both 6He and 6Li in a three-body model of α + N + N. The ground state solution for the three-body Hamiltonian is obtained accurately using correlated basis functions. The distribution depends on the type of the N-N interaction. With use of a realistic potential, the 6He momentum distribution exhibits a dip around 2fm-1 characteristic of S-wave motion. In contrast to this, the 6Li momentum distribution is similar to that of the deuteron no dip appears because it is filled with the D-wave component arising from the tensor force. © 2008 IOP Publishing Ltd.
• Reaction cross sections of carbon isotopes incident on a proton

  B. Abu-Ibrahim, W. Horiuchi, A. Kohama, Y. Suzuki

  Physical Review C - Nuclear Physics 77 3 2008年03月17日 [査読有り][通常論文]
   

  We systematically study total reaction cross sections of carbon isotopes with N=6-16 on a proton target for wide range of incident energies. An emphasis is put on the difference from the case of a carbon target. The calculations include the reaction cross sections of C19,20,22 at 40A MeV, the data of which have recently been measured at RIKEN. The Glauber theory is used to calculate the reaction cross sections. To describe the intrinsic structure of the carbon isotopes, we use a Slater determinant generated from a phenomenological mean-field potential, and construct the density distributions. To go beyond the simple mean-field model, we adopt two types of dynamical models: One is a core+n model for odd-neutron nuclei, and the other is a core+n+n model for C16 and C22. We propose empirical formulas which are useful in predicting unknown cross sections. © 2008 The American Physical Society.
• Reaction cross sections of carbon isotopes incident on a proton

  B. Abu-Ibrahim, W. Horiuchi, A. Kohama, Y. Suzuki

  PHYSICAL REVIEW C 77 3 1 - 34607 2008年03月 [査読有り][通常論文]
   

  We systematically study total reaction cross sections of carbon isotopes with N = 6-16 on a proton target for wide range of incident energies. An emphasis is put on the difference from the case of a carbon target. The calculations include the reaction cross sections of C-19,C-20,C-22 at 40A MeV, the data of which have recently been measured at RIKEN. The Glauber theory is used to calculate the reaction cross sections. To describe the intrinsic structure of the carbon isotopes, we use a Slater determinant generated from a phenomenological mean-field potential, and construct the density distributions. To go beyond the simple mean-field model, we adopt two types of dynamical models: One is a core+n model for odd-neutron nuclei, and the other is a core+n+n model for C-16 and C-22. We propose empirical formulas which are useful in predicting unknown cross sections.
• Momentum distribution and correlation of two-nucleon relative motion in He-6 and Li-6

  W. Horiuchi, Y. Suzuki

  PHYSICAL REVIEW C 76 2 1 - 24311 2007年08月 [査読有り][通常論文]
   

  The momentum distribution of relative motion between two nucleons gives information on the correlation in nuclei. The momentum distribution is calculated for both He-6 and Li-6, which are described in a three-body model of alpha+N+N. The ground-state solution for the three-body Hamiltonian is obtained accurately using correlated basis functions. The momentum distribution depends on the potential model for the N-N interaction. With use of a realistic potential, the He-6 momentum distribution exhibits a dip around 2 fm(-1) characteristic of S-wave motion. In contrast to this, the Li-6 momentum distribution is very similar to that of the deuteron; no dip appears because it is filled with the D-wave component arising from the tensor force.
• Systematic analysis of reaction cross sections of carbon isotopes

  W. Horiuchi, Y. Suzuki, B. Abu-Ibrahim, A. Kohama

  Physical Review C - Nuclear Physics 75 4 2007年04月20日 [査読有り][通常論文]
   

  We systematically analyze total reaction cross sections of carbon isotopes with N= 6-16 on a C12 target for wide range of incident energy. The intrinsic structure of the carbon isotope is described by a Slater determinant generated from a phenomenological mean-field potential, which reasonably well reproduces the ground-state properties for most of the even N isotopes. We need separate studies not only for odd nuclei but also for C16 and C22 to improve their wave functions. The density of the carbon isotope is constructed by eliminating the effect of the center-of-mass motion. For the calculations of the cross sections, we take two schemes, the Glauber approximation and the eikonal model using a global optical potential. Both the reaction models successfully reproduce low and high incident energy data on the cross sections of C12, C13, and C16 on C12. The calculated reaction cross sections of C15 are found to be considerably smaller than the empirical values observed at low energy. We find a consistent parametrization of the nucleon-nucleon scattering amplitude, differently from previous ones. Finally, we predict the total reaction cross section of C22 on C12. © 2007 The American Physical Society.
• Systematic analysis of reaction cross sections of carbon isotopes

  W. Horiuchi, Y. Suzuki, B. Abu-Ibrahim, A. Kohama

  PHYSICAL REVIEW C 75 4 1 - 44607 2007年04月 [査読有り][通常論文]
   

  We systematically analyze total reaction cross sections of carbon isotopes with N= 6-16 on a C-12 target for wide range of incident energy. The intrinsic structure of the carbon isotope is described by a Slater determinant generated from a phenomenological mean-field potential, which reasonably well reproduces the ground-state properties for most of the even N isotopes. We need separate studies not only for odd nuclei but also for C-16 and C-22 to improve their wave functions. The density of the carbon isotope is constructed by eliminating the effect of the center-of-mass motion. For the calculations of the cross sections, we take two schemes, the Glauber approximation and the eikonal model using a global optical potential. Both the reaction models successfully reproduce low and high incident energy data on the cross sections of C-12, C-13, and C-16 on C-12. The calculated reaction cross sections of C-15 are found to be considerably smaller than the empirical values observed at low energy. We find a consistent parametrization of the nucleon-nucleon scattering amplitude, differently from previous ones. Finally, we predict the total reaction cross section of C-22 on C-12.
• C-22: An s-wave two-neutron halo nucleus

  W. Horiuchi, Y. Suzuki

  PHYSICAL REVIEW C 74 3 1 - 34311 2006年09月 [査読有り][通常論文]
   

  A dripline nucleus C-22 is studied in a Borromean three-body model of C-20+n+n. The valence neutrons, interacting via a realistic potential, are constrained to be orthogonal to the occupied orbits in C-20. We obtain ample results supporting that C-22 is an ideal s-wave two-neutron halo nucleus: The ground state is bound by 390-570 keV, the root mean square neutron and proton radii are 4.0 and 2.4 fm, and the two neutrons are predominantly in (s(1/2))(2) orbits. The binding mechanism of C-22 is discussed. One- and two-body density distributions elucidate the halo character as well as the correlated motion of the neutrons. The reaction cross sections of C-22+C-12 collisions are predicted.
• Structure of and E2 transition in C-16 in a C-14 + n+n model

  W Horiuchi, Y Suzuki

  PHYSICAL REVIEW C 73 3 1 - 37304 2006年03月 [査読有り][通常論文]
   

  A three-body model of C-14 +n+n is applied to study the energy spectrum and the hindered E2 transition in C-16. A realistic two-nucleon potential is used for the valence neutrons. Both spin-singlet and spin-triplet components for the neutrons are taken into account. The three-body problem with a Pauli constraint is solved in a stochastic variational method. For the n-C-14 potential chosen to reproduce the properties of C-15, the low-lying energy spectrum agrees reasonably well with experiment, but the ground state is predicted to be about 1 MeV high. The calculated B(E2; 2(1)(+)-> 0(1)(+)) value is about twice the measured value if the polarization charge of the valence neutrons is taken to be the same as that required to fit the C-15 data. The correlated motion of the valence neutrons is displayed through the two-neutron density distribution.
• Structure of and E2 transition in C16 in a C14 + n + n model

  W. Horiuchi, Y. Suzuki

  Physical Review C - Nuclear Physics 73 3 2006年 [査読有り][通常論文]
   

  A three-body model of C14 +n+n is applied to study the energy spectrum and the hindered E2 transition in C16. A realistic two-nucleon potential is used for the valence neutrons. Both spin-singlet and spin-triplet components for the neutrons are taken into account. The three-body problem with a Pauli constraint is solved in a stochastic variational method. For the n-C14 potential chosen to reproduce the properties of C15, the low-lying energy spectrum agrees reasonably well with experiment, but the ground state is predicted to be about 1 MeV high. The calculated B(E2 21+→01+) value is about twice the measured value if the polarization charge of the valence neutrons is taken to be the same as that required to fit the C15 data. The correlated motion of the valence neutrons is displayed through the two-neutron density distribution. © 2006 The American Physical Society.

その他活動・業績

• Kaonic deuterium from realistic antikaon-nucleon interaction

  Horiuchi Wataru, Hyodo Tetsuo, Weise Wolfram MESON 2018 - 15TH INTERNATIONAL WORKSHOP ON MESON PHYSICS 199 2019年 [査読有り][通常論文]
  
• Kaonic deuterium and low-energy antikaon-nucleon interaction

  Horiuchi Wataru, Hyodo Tetsuo, Weise Wolfram INTERNATIONAL CONFERENCE ON EXOTIC ATOMS AND RELATED TOPICS - EXA2017 181 2018年 [査読有り][通常論文]
  
• Competition between Nucleon- and (K)over-barNN-Cluster Correlations in Kaonic Nuclear Systems

  Horiuchi W, Hyodo T PROCEEDINGS OF THE 4TH INTERNATIONAL WORKSHOP ON STATE OF THE ART IN NUCLEAR CLUSTER PHYSICS (SOTANCP4) 2038 2018年 [査読有り][通常論文]
  
• Alpha clustering near nuclear surface and harmonic-oscillator excitations

  W. Horiuchi, Y. Suzuki Journal of Physics: Conference Series 863 (1) 2017年07月04日 [査読有り][通常論文]
   

  We quantify how it is difficult to describe an alpha(α)-cluster state with single-particle harmonic-oscillator (HO) bases in the low-lying16O states by counting the number of HO quanta of12 C+n+n+p+p five-body wave functions. We also discuss how many HO quanta are needed for describing a localized α cluster near the nuclear surface towards understanding of the shell and cluster coexistence in heavier nuclei.
• Time-Dependent Correlated Gaussian Approach to the Nuclear Response of Few-Nucleon Systems

  Rie Sekine, Wataru Horiuchi FEW-BODY SYSTEMS 58 (3) 2017年06月 [査読有り][通常論文]
   

  Nuclear responses involve the information on nuclear dynamics as well as underlying interactions. To describe them theoretically, one faces the difficulty in treating many-body continuum states. A newly developed time-dependent correlated Gaussian basis allows us to describe the response function without explicit construction of the many-body continuum states. As simple examples, the photoabsorption reactions of H-2 and He-3 are presented. In both cases, the calculations are remarkably improved compared to those with time-independent correlated Gaussian.
• Towards an ab initio description of light-nuclei radiative captures

  Jeremy Dohet-Eraly, Petr Navratil, Sofia Quaglioni, Wataru Horiuchi, Guillaume Hupin 21ST INTERNATIONAL CONFERENCE ON FEW-BODY PROBLEMS IN PHYSICS 113 2016年 [査読有り][通常論文]
   

  The He-3(alpha, gamma)Be-7 and H-3(alpha, gamma)Li-7 astrophysical S factors are evaluated at low collision energies (less than 2.5 MeV in the centre-of-mass frame) within the no-core shell model with continuum using a renormalized chiral nucleon-nucleon interaction.
• Solving the time-dependent few-body Schrodinger equation within a basis expansion method

  Rie Sekine, Wataru Horiuchi 21ST INTERNATIONAL CONFERENCE ON FEW-BODY PROBLEMS IN PHYSICS 113 2016年 [査読有り][通常論文]
   

  Nuclear responses are a source of information on nuclear structure and reaction dynamics. We develop a method to study the nuclear response by solving time dependent equation. We expand the wave function by many correlated Gaussian functions. In this paper, the photoabsorption of He-3 is presented as a simple example. Measured photoabsorption cross sections are reproduced up to 20 MeV.
• Five-body calculation with Pauli constraint for shell-and cluster-structure in O-16

  Wataru Horiuchi, Yasuyuki Suzuki 21ST INTERNATIONAL CONFERENCE ON FEW-BODY PROBLEMS IN PHYSICS 113 2016年 [査読有り][通常論文]
   

  A C-12+four-nucleon (4N) five-body model is applied for the ground and first excited states of O-16. The 4N configurations are selected in a wide Hilbert space under the fulfillment of the Pauli principle excluding the occupied orbits in C-12. The energies of both the states are obtained in excellent agreement with experiment. Analysis of the wave functions indicates a spatially localized alpha-particle-like cluster structure for the excited state and a shell-model-like delocalized structure for the ground state. The difficulty of describing the cluster structure by a standard shell model approach is discussed by calculating components of the harmonic-oscillator quanta in the wave functions.
• Systematic analysis of total reaction cross sections of unstable nuclei with Glauber theory

  Wataru,Horiuchi, Tsunenori,Inakura, Nakatsukasa,Takashi, Yasuyuki,Suzuki JPS Conference Proceedings 6 030079 2015年 [査読有り][通常論文]
  
• Tensor correlations probed by electroweak responses

  W. Horiuchi, Y. Suzuki INPC 2013 - INTERNATIONAL NUCLEAR PHYSICS CONFERENCE, VOL. 1 66 2014年 [査読有り][通常論文]
   

  In this contribution, we present our recent study on the electroweak response functions with realistic nuclear forces and discuss their relation to tensor correlations. The observed resonance energies and widths of the negative-parity levels are all in fair agreement with those calculated from both the spin-dipole and electric-dipole strength functions. Spin-dipole sum rules are discussed in relation to tensor correlations in the ground state of He-4. Possible observables are suggested to probe the tensor correlations.
• Dynamics of nuclear four- and five-body systems with correlated Gaussian method

  W. Horiuchi, Y. Suzuki 3RD INTERNATIONAL WORKSHOP ON STATE OF THE ART IN NUCLEAR CLUSTER PHYSICS 569 (1) 2014年 [査読有り][通常論文]
   

  We report our recent applications of the correlated Gaussian (CG) method to nuclear four- and five-body systems: (I) Spin-dipole response functions of He-4 and (II) O-16 as a C-12+n + n + p + p five-body model. The CG is flexible to describe complex few-nucleon dynamics. The above examples actually demonstrate the power of the CG, giving a simultaneous description of both four-nucleon bound and unbound states using a realistic nuclear force, and both shell- and cluster-configurations in the ground and first excited 0(+) states of O-16.
• Multiple-scattering effects in proton- and alpha-nucleus reactions with Glauber theory

  S. Hatakeyama, S. Ebata, W. Horiuchi, M. Kimura 3RD INTERNATIONAL WORKSHOP ON STATE OF THE ART IN NUCLEAR CLUSTER PHYSICS 569 (1) 2014年 [査読有り][通常論文]
   

  We study the total reaction and elastic differential cross sections for proton-nucleus and He-4-nucleus reactions in the framework of the Glauber theory which describes multiple-scattering processes. The input wave functions are obtained using the Skyrme-Hartree-Fock method and prepared for a wide range of mass numbers, O, Ca, Ni, Sn, and Pb isotopes. The theory reproduces experimental data very well. An effect of the multiple scattering is discussed by comparing with a standard optical-limit approximation. We see that the multiple-scattering effects play a crucial role, especially in enhancing the elastic differential cross sections at large scattering angles.
• Unified description of shell and cluster coexistence in O-16 with a five-body model

  W. Horiuchi, Y. Suzuki INPC 2013 - INTERNATIONAL NUCLEAR PHYSICS CONFERENCE, VOL. 1 66 2014年 [査読有り][通常論文]
   

  A famous and long-standing problem so-called the "mysterious" 0(+) state in O-16 is discussed with a single scheme, a C-12 plus four-nucleon five-body model. The wave function is expressed in terms of explicitly correlated Gaussian functions. Preliminary results show that the energy levels are in good agreement with experiment. A well-developed C-12+alpha cluster structure appears in the first excited 0(+) state, whereas the ground state has shell model like structure.
• Ab Initio Study of Electroweak Responses of He-4

  W. Horiuchi, Y. Suzuki, K. Arai FEW-BODY SYSTEMS 54 (7-10) 1343 -1347 2013年08月 [査読有り][通常論文]
   

  In this contribution, we discuss the electroweak responses of He-4 based on a full four-body calculation. The wave function of the ground state is obtained accurately using an explicitly correlated basis. Four-body final states are expressed in a superposition of many basis functions including configurations which have 3+1 and 2+1+1 cluster partitions of four-nucleon system explicitly. The continuum is properly treated by taking the two approaches: one is the complex scaling method and the other is the microscopic R-matrix method. The calculated photoabsorption cross sections agree up to the rest energy of a pion. The spin-dipole strength function is also presented and its relationship between the spectrum of He-4 is discussed.
• Universality of Short-Range Nucleon-Nucleon Correlations in Nuclei

  W. Horiuchi, H. Feldmeier, T. Neff, Y. Suzuki FEW-BODY SYSTEMS 54 (1-4) 279 -282 2013年03月 [査読有り][通常論文]
   

  We investigate the short-range correlations in light nuclei. The highly correlated many-body states are obtained with an explicitly correlated basis which enables us to get a precise solution of a many-body Schrodinger equation for a realistic interaction. We show two-body density distributions for the different spin-isospin channels calculated from three- and four-body states to investigate the short-range correlations between nucleon pairs. At distances below 1 fm a universal behavior is found which does not depend on the many-body states. The universality is also seen in high momentum components of the two-body momentum distributions.
• 日本の核物理の将来レポート, 計算核物理

  根村英克, 清水則孝, 阿部喬, 江尻信司, 古本猛憲, 堀内渉, 板垣直之, 藏増嘉伸, 中務孝, 佐々木勝一, 住吉光介, 大西明 原子核研究 57 (Supplement 2) 275 -312 2013年02月 [査読有り][通常論文]
  
• Cluster structure in light nuclei studied with few-body models

  W. Horiuchi, Y. Suzuki Journal of Physics: Conference Series 436 (1) 2013年 [査読有り][通常論文]
   

  We present our attempt at describing the low-lying states of A = 16 nuclei in a single scheme, a 12C core-plus-few-nucleon model. Promising results are obtained for 16C and 16O, which suggest the coexistence of single-particle and cluster structure.
• Global optical potential for nucleus-nucleus systems from 50 MeV/u to 400 MeV/u (vol 85, 044607, 2012)

  T. Furumoto, W. Horiuchi, M. Takashina, Y. Yamamoto, Y. Sakuragi PHYSICAL REVIEW C 85 (6) 2012年06月 [査読無し][通常論文]
  
• From nucleons to nuclei to fusion reactions

  S. Quaglioni, P. Navratil, R. Roth, W. Horiuchi IUPAP C20 CONFERENCE ON COMPUTATIONAL PHYSICS (CCP 2011) 402 (1) 2012年 [査読有り][通常論文]
   

  Nuclei are prototypes of many-body open quantum systems. Complex aggregates of protons and neutrons that interact through forces arising from quantum chromo-dynamics, nuclei exhibit both bound and unbound states, which can be strongly coupled. In this respect, one of the major challenges for computational nuclear physics, is to provide a unified description of structural and reaction properties of nuclei that is based on the fundamental underlying physics: the constituent nucleons and the realistic interactions among them. This requires a combination of innovative theoretical approaches and high-performance computing. In this contribution, we present one of such promising techniques, the ab initio no-core shell model/resonating-group method, and discuss applications to light nuclei scattering and fusion reactions that power stars and Earth-base fusion facilities.
• Nuclear Reactions with a Realistic Nuclear Interaction Using a Square Integrable Basis

  Wataru Horiuchi, Yasuyuki Suzuki, Koji Arai PROGRESS OF THEORETICAL PHYSICS SUPPLEMENT (196) 125 -130 2012年 [査読有り][通常論文]
   

  We discuss the controversy of the photoabsorption cross section of He-4 based on a full four-body calculation. The continuum is properly treated by taking the following two approaches: one is the complex scaling method and the other is the microscopic R-matrix method, which are widely used method for describing continuum state with a square integrable basis. The wave function of the ground state is obtained accurately using an explicitly correlated basis. Four-body final states are expressed in a superposition of many basis functions including configurations dividing He-4 into 3+1 and 2+1+1 partitions explicitly, which are important for describing the low-lying photoabsorption cross section. The results agree with the other theoretical works and sonic measurements but disagree with one of the recent data.
• Ab Initio Calculations of Light-Ion Reactions

  Petr Navratil, Sofia Quaglioni, Robert Roth, Wataru Horiuchi PROGRESS OF THEORETICAL PHYSICS SUPPLEMENT (196) 117 -124 2012年 [査読有り][通常論文]
   

  The exact treatment of nuclei starting from the constituent nucleons and the fundamental interactions among them has been a long-standing goal in nuclear physics. In addition to the complex nature of nuclear forces, one faces the quantum-mechanical many-nucleon problem governed by an interplay between bound and continuum states. In recent years, significant progress has been made in ab initio nuclear structure and reaction calculations based on input from QCD employing Hamiltonians constructed within chiral effective field theory. In this contribution, we present one of such promising techniques capable of describing simultaneously both bound and scattering states in light nuclei. By combining the resonating-group method (RGM) with the ab initio no-core shell model (NCSM), we complement a microscopic cluster approach with the use of realistic interactions and a microscopic and consistent description of the clusters. We discuss applications to light nuclei scattering, radiative capture and fusion reactions.
• Strength Function in Continuum with a Square Integrable Basis

  Wataru Horiuchi, Yasuyuki Suzuki, Daniel Baye FEW-BODY SYSTEMS 50 (1-4) 455 -458 2011年05月 [査読有り][通常論文]
   

  We present a new approach to describe the three-body continuum with a square integrable basis and show some examples to assess its efficiency. The formulation is done elegantly in the hyperspherical formalism and the tail behavior is appropriately corrected with use of the Green's function. The efficiency of this approach is shown in a simple solvable problem by calculating the electric dipole strength function of a three-body system and comparing it to that obtained with the complex scaling method, which is widely used for calculating the strength function.
• ELECTRO-WEAK TRANSITIONS OF He-4 USING REALISTIC NUCLEAR INTERACTIONS

  Wataru Horiuchi, Yasuyuki Suzuki, Toru Sato INTERNATIONAL JOURNAL OF MODERN PHYSICS E-NUCLEAR PHYSICS 20 (4) 781 -784 2011年04月 [査読有り][通常論文]
   

  In this contribution we discuss electro-weak induced transitions involving He-4. The wave function of the ground state is obtained accurately using an explicitly correlated basis with a realistic nuclear interaction. Four-body final states are expressed in a superposition of many basis functions which contain important configurations for the low-lying transition strength. Resonant and continuum states are treated properly in the complex scaling method. The discussion is mainly focused on the electric dipole strength. Also, we mention those transitions induced by the weak interactions which are important for a neutrino-nucleus reaction.
• Universality of short-range correlations in light nuclei

  W. Horiuchi, H. Feldmeier, T. Neff, Y. Suzuki MANY-BODY CORRELATIONS FROM DILUTE TO DENSE NUCLEAR SYSTEMS (MBC 2011) 321 (1) 2011年 [査読有り][通常論文]
   

  In this contribution, we investigate the structure of short-range correlations in many-body states. We obtain the highly correlated many-body states with an explicitly correlated basis which enables us to get a precise solution of a many-body Schrodinger equation for a realistic interaction. We show two-body density distributions calculated from three-and four-body states to investigate the short-range correlations between nucleon pairs. At distances below 1 fm a universal behavior is found which does not depend on the many-body states. The universality is also seen in the high momentum components of the two-body momentum distributions.
• TOTAL REACTION CROSS SECTIONS OF LIGHT NEUTRON-RICH NUCLEI IN THE GLAUBER APPROXIMATION

  Akihisa Kohama, Badawy Abu-Ibrahim, Wataru Horiuchi, Shohei Iwasaki, Yasuyuki Suzuki MODERN PHYSICS LETTERS A 25 (21-23) 1963 -1966 2010年07月 [査読有り][通常論文]
   

  We report our recent numerical results of total reaction cross sections of light neutron-rich nuclei, such as carbons and oxygens, in the Glauber approximation to study the exotic structure of neutron-rich unstable nuclei.
• A UNIFIED DESCRIPTION OF PARTICLE-HOLE AND CLUSTER EXCITATIONS IN A FEW-BODY APPROACH

  W. Horiuchi, Y. Suzuki MODERN PHYSICS LETTERS A 25 (21-23) 1899 -1902 2010年07月 [査読有り][通常論文]
   

  We attempt at describing the particle-hole and cluster excitations for A similar to 16 nuclei in a single scheme of a (12)C core plus few-nucleon model. A nucleon-(12)C potential is derived based on a collective model taking into account the core excitation and its parameters are determined to reproduce the low-lying spectrum of (13)C. The model is tested in three- and four-body systems, (14)C, (14)N and (15)C. Preliminary results of the five-body systems for (16)C and (16)O are reported.
• PROBING THE WEAKLY-BOUND NEUTRON ORBIT OF Ne-31 WITH ONE-NEUTRON REMOVAL REACTIONS

  P. Capel, W. Horiuchi, Y. Suzuki, D. Baye MODERN PHYSICS LETTERS A 25 (21-23) 1882 -1885 2010年07月 [査読有り][通常論文]
   

  A candidate of a neutron-halo nucleus, Ne-31, contains a single neutron in the pf shell. Within Glauber and eikonal models, we analyze reactions used to study Ne-31. We show in a Ne-30+n model that the magnitudes of the total reaction and above all of the one-neutron removal cross sections of Ne-31 on C-12 and Pb-208 targets strongly depend on the orbital angular momentum of the valence neutron, thereby providing efficient ways to determine the structure of Ne-31 ground state. We also show that elastic-breakup observables exhibit a strong dependence upon the orbital of the valence neutron.
• Reaction cross sections of carbon isotopes incident on a proton (vol 77, 034607, 2008)

  B. Abu-Ibrahim, W. Horiuchi, A. Kohama, Y. Suzuki PHYSICAL REVIEW C 81 (1) 2010年01月 [査読無し][通常論文]
  
• Reaction cross sections of carbon isotopes incident on a proton (vo 77, 034607, 2008)

  B. Abu-Ibrahim, W. Horiuchi, A. Kohama, Y. Suzuki PHYSICAL REVIEW C 80 (2) 2009年08月 [査読無し][通常論文]
  
• FOUR-BODY CALCULATION FOR EXCITED STATES OF (HE)-H-4

  Wataru Horiuchi, Yasuyuki Suzuki INTERNATIONAL JOURNAL OF MODERN PHYSICS A 24 (11) 2134 -2141 2009年04月 [査読有り][通常論文]
   

  Four-body calculations with explicitly correlated Gaussian bases are performed for excited states of He-4. All the levels below E-x=26MeV are reproduced reasonably well using realistic potentials. An analysis is made to show how the 0(2)(+) state becomes a resonance but those having almost the same structure as this state in different spin-isospin channels are not observed as resonances. The calculation of spectroscopic amplitudes, nucleon decay widths, and spin-dipole transition strengths demonstrates that the 0(2)(+) state and the three lowest-lying negative-parity states with 0(-) and 2(-) have H-3+p and He-3+n cluster configurations, leading to the interpretation that these negative-parity states are the inversion-doublet partners of the 0(2)(+) state.
• PROGRESS ON FEW-BODY CALCULATIONS: THE ROLE OF TENSOR FORCE

  Wataru Horiuchi, Yasuyuki Suzuki MODERN PHYSICS LETTERS A 24 (11-13) 992 -997 2009年04月 [査読有り][通常論文]
   

  One of the methods to obtain a precise solution of a few-body equation is to expand the orbital part of the wave function into the correlated Gaussian with double global vectors. In this contribution, we report our recent studies applying this method to light nuclei, (i) excited states of (4)He and (ii) two-nucleon momentum distribution in (6)He and (6)Li, especially focusing on the importance of the tensor force.
• Application of correlated basis to a description of continuum states

  W. Horiuchi, Y. Suzuki 19TH INTERNATIONAL IUPAP CONFERENCE ON FEW-BODY PROBLEMS IN PHYSICS 3 2009年 [査読有り][通常論文]
   

  In this contribution, we present a simple approach to the scattering problem using the technique for discrete states, particularly developed for a basis expansion method. An idea is very simple and the following: First, we calculate a spectroscopic amplitude (SA) between two subsystems from the "discretized" wave function obtained in the bound-state calculation. When one uses square-integrable basis, the asymptotics of the SA shows ill behavior. The behavior is easily corrected by use of the Green's function, and then phase shift is accurately determined from the SA with "correct" asymptotics. Test examples confirm the accuracy of the method. The alpha+n scattering is described using realistic nucleon-nucleon potentials. The 1/2(+) phase shifts are in reasonable agreement with experiment, and gain contributions both from the tensor and central components of the nucleon-nucleon potential. The 3/2(-) and 1/2(-) phase shifts obtained in a single-channel calculation are too small in comparison with experiment and point out the importance of including distorted configurations of the alpha particle.
• Systematic analysis of reaction cross sections of carbon isotopes

  W. Horiuchi, Y. Suzuki, B. Abu-Ibrahim, A. Kohama PHYSICAL REVIEW C 76 (3) 2007年09月 [査読有り][通常論文]
  
• Dynamics of macroscopic and microscopic three-body systems

  Y. Suzuki, Y. Fujiwara, W. Horiuchi, H. Matsumura, M. Orabi NUCLEAR PHYSICS A 790 223C -228C 2007年06月 [査読有り][通常論文]
   

  A macroscopic approach to a three-body system is presented in order to discuss the consequences of redundant states or Pauli-forbidden states as well as the use of nonlocal potentials of a microscopic origin. The examples include C-22=C-20+n+n, C-12=alpha+alpha+alpha, and t=p+n+n.
• Structure of and E2 transition in C-16 in a C-14+n+n model (vol 73, art no 037304, 2006)

  W. Horiuchi, Y. Suzuki PHYSICAL REVIEW C 74 (1) 2006年07月 [査読無し][通常論文]
  

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