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Nuclear Theory·nucl-th

Tuesday·February 15, 2022

11 papers—6 primary·5 cross-listed

All11Primary6Cross-lists5
  1. 01

    [Submitted on 11 Feb 2022]

    Multi-channel experimental and theoretical constraints for the Cd(Ne,F)In charge exchange reaction at 306 MeV

    S. Burrello🇩🇪 · S. Calabrese🇮🇹 · F. Cappuzzello🇮🇹 · D. Carbone🇮🇹 · M. Cavallaro🇮🇹 · M. Colonna🇮🇹 · J. A. Lay🇪🇸 · H. Lenske🇩🇪 · C. Agodi🇮🇹 · J. L. Ferreira🇧🇷 · S. Firat🇹🇷 · A. Hacisalihoglu🇹🇷 and 34 other authors

    Charge exchange (CE) reactions offer a major opportunity to excite nuclear isovector modes, providing clues about the nuclear interaction in the medium. Moreover, double charge exchange (DCE) reactions are proving to be a tempting tool to access nuclear transition matrix elements (NME) related to double beta-decay processes. Through a multi-channel experimental analysis and a consistent theoretical approach of the Cd(Ne,F)In single charge exchange (SCE) reaction at 306 MeV, we aim at disentangling from the experimental cross section the contribution of the competing mechanisms, associated with second or higher order sequential transfer and inelastic processes. We measured excitation energy spectra and absolute cross sections for elastic + inelastic, one-proton transfer and SCE channels, using the MAGNEX large acceptance magnetic spectrometer to detect the ejectiles. For the first two channels, we also extracted the experimental cross section angular distributions. The experimental data are compared with theoretical predictions obtained by performing two-step distorted wave Born approximation and coupled reaction channel calculations. We employ spectroscopic amplitudes for single-particle transitions derived within a large-scale shell model approach and different optical potentials for modeling the initial and the final state interactions. The present study significantly mitigates the possible model dependence existing in the description of these complex reaction mechanisms, thanks to the reproduction of several channels at once. In particular, our work demonstrates that the two-step transfer mechanisms produce a non negligible contribution to the total cross section of the Cd(Ne,F)In reaction channel, although a relevant fraction is still missing, being ascribable to the direct SCE mechanism, which is not addressed here.

    Comments:
    21 pages, 11 figures
    Subjects:
    Nuclear Theory (nucl-th); Nuclear Experiment (nucl-ex)
    arXiv:
    2202.05918 [pdf]
    PRC(2022)·35 citations
  2. 02

    [Submitted on 12 Feb 2022]

    Scaling properties of exclusive vector meson production cross section from gluon saturation

    Gregory Matousek🇺🇸 · Vladimir Khachatryan🇺🇸 · Jinlong Zhang🇨🇳

    It is already known from phenomenological studies that in exclusive deep-inelastic scattering off nuclei there appears to be a scaling behavior of vector meson production cross section in both nuclear mass number, , and photon virtuality, , which is strongly modified due to gluon saturation effects. In this work we continue those studies in a realistic setup based upon using the Monte Carlo event generator Sar{\em t}re. We make quantitative predictions for the kinematics of the Electron-Ion Collider, focusing on this and scaling picture, along with establishing a small region of squared momentum transfer, , where there are signs of this scaling that may potentially be observed at the EIC. Our results are represented as pseudo-data of vector meson production diffractive cross section and/or their ratios, which are obtained by parsing data collected by the event generator through smearing functions, emulating the proposed detector resolutions for the future EIC.

    Comments:
    26 pages and 18 figures
    Subjects:
    Nuclear Theory (nucl-th); High Energy Physics — Phenomenology (hep-ph); Nuclear Experiment (nucl-ex)
    arXiv:
    2202.05981 [pdf]
    Eur.Phys.J.Plus(2023)·2 citations
  3. 03

    [Submitted on 13 Feb 2022]

    Theory of kaon-nuclear systems

    Tetsuo Hyodo🇯🇵 · Wolfram Weise🇩🇪

    The strong interaction between an antikaon and a nucleon is at the origin of various interesting phenomena in kaon-nuclear systems. In particular, the interaction in the isospin channel is sufficiently attractive to generate a quasi-bound state, the resonance, below the threshold. Based on this picture, it may be expected that the interaction also generates quasi-bound states in kaon-nuclear systems, sometimes called kaonic nuclei. At the same time, the quasi-bound picture of the is also related to the discussion of hadronic molecules in hadron spectroscopy. Here an overview is presented of the theoretical studies developed for kaon-nucleon and kaon-nuclear systems. We start from the modern understanding of the resonance. We then discuss the interaction and various aspects of few-body kaonic nuclei. Heavier kaon-nuclear systems are examined from the viewpoint of nuclear many-body physics, with focus on the properties of antikaons in nuclear matter. Related topics, such as the momentum correlation functions in high-energy collisions and the studies of kaonic atoms, are also discussed.

    Comments:
    32 pages, 16 figures, Contribution to the "Handbook of Nuclear Physics", Springer, 2022, edited by I. Tanihata, H. Toki and T. Kajino
    Subjects:
    Nuclear Theory (nucl-th); High Energy Physics — Phenomenology (hep-ph)
    arXiv:
    2202.06181 [pdf]
    15 citations
  4. 04

    [Submitted on 14 Feb 2022]

    Reply to Comment on "Phase-space consideration on barrier transmission in a time-dependent variational approach with superposed wave packets"

    Akira Ono

    In the paper by Hasegawa, Hagino and Tanimura (HHT) [Phys. Lett. B 808 (2020) 135693, arXiv:2006.06944], they concluded that quantum tunneling was simulated by a time-dependent generator coordinate method (TDGCM). In contrast, difficulties of TDGCM in describing quantum tunneling were pointed out by Ono in the paper [Phys. Lett. B 826 (2022) 136931, arXiv:2201.02966]. Recently, HHT submitted a comment [arXiv:2202.00513v1], by which they appear to give some counterarguments to Ono's paper. Here I examine their arguments, reviewing the main points of Ono's paper. The confusion in HHT's arguments may be mostly resolved by recognizing how the wave packets interfere with each other when they are coherently superposed.

    Comments:
    5 pages, 4 figures, reply to arXiv:2202.00513v1, includes review of arXiv:2201.02966
    Subjects:
    Nuclear Theory (nucl-th)
    arXiv:
    2202.06454 [pdf]
    1 citation
  5. 05

    [Submitted on 14 Feb 2022]

    Asymmetric nuclear matter in relativistic mean-field models with isoscalar- and isovector-meson mixing

    Tsuyoshi Miyatsu🇰🇷 · Myung-Ki Cheoun🇰🇷 · Koichi Saito🇯🇵

    Using the relativistic mean-field model with nonlinear couplings between the isoscalar and isovector mesons, we study the properties of isospin-asymmetric nuclear matter. Not only the vector mixing, , but also the quartic interaction due to the scalar mesons, , is taken into account to investigate the density dependence of nuclear symmetry energy, , and the neutron-star properties. It is found that the meson increases at high densities, whereas the - mixing makes soft above the saturation density. Furthermore, the meson and its mixing have a large influence on the radius and tidal deformability of a neutron star. In particular, the - mixing reduces the neutron-star radius, and, thus, the present calculation can simultaneously reproduce the dimensionless tidal deformabilities of a canonical neutron star observed from the binary neutron star merger, GW170817, and from the compact binary coalescence, GW190814.

    Comments:
    11 pages, 14 figures, 2 tables
    Subjects:
    Nuclear Theory (nucl-th); High Energy Astrophysical Phenomena (astro-ph.HE); Nuclear Experiment (nucl-ex)
    arXiv:
    2202.06468 [pdf]
    ApJ(2022)·41 citations
  6. 06

    [Submitted on 14 Feb 2022]

    Transport Model Comparison Studies of Intermediate-Energy Heavy-Ion Collisions

    Hermann Wolter (1)🇩🇪 · Maria Colonna (2)🇮🇹 · Dan Cozma (3)🇷🇴 · Pawel Danielewicz (4,5)🇺🇸 · Che Ming Ko (6)🇺🇸 · Rohit Kumar (4)🇺🇸 · Akira Ono (7)🇯🇵 · ManYee Betty Tsang (4,5)🇺🇸 · Jun Xu (8,9)🇨🇳 · Ying-Xun Zhang (10,11)🇨🇳 · Elena Bratkovskaya (12,13)🇩🇪 · Zhao-Qing Feng (14)🇨🇳 and 40 other authors

    Transport models are the main method to obtain physics information from low to relativistic-energy heavy-ion collisions. The Transport Model Evaluation Project (TMEP) has been pursued to test the robustness of transport model predictions in reaching consistent conclusions from the same type of physical model. Calculations under controlled conditions of physical input and set-up were performed with various participating codes. These included both calculations of nuclear matter in a box with periodic boundary conditions, and more realistic calculations of heavy-ion collisions. In this intermediate review, we summarize and discuss the present status of the project. We also provide condensed descriptions of the 26 participating codes, which contributed to some part of the project. These include the major codes in use today. We review the main results of the studies completed so far. They show, that in box calculations the differences between the codes can be well understood and a convergence of the results can be reached. These studies also highlight the systematic differences between the two families of transport codes, known as BUU and QMD type codes. However, when the codes were compared in full heavy-ion collisions using different physical models, as recently for pion production, they still yielded substantially different results. This calls for further comparisons of heavy-ion collisions with controlled models and of box comparisons of important ingredients, like momentum-dependent fields, which are currently underway. We often indicate improved strategies in performing transport simulations and thus provide guidance to code developers. Results of transport simulations of heavy-ion collisions from a given code will have more significance if the code can be validated against benchmark calculations such as the ones summarized in this review.

    Comments:
    114 pages, 14 figures, 479 references, accepted for publication in Progress of Particle and Nuclear Phsics
    Subjects:
    Nuclear Theory (nucl-th); Nuclear Experiment (nucl-ex)
    arXiv:
    2202.06672 [pdf]
    PPNP(2022)·161 citations

Affiliations

first authorsco-authorsvia INSPIRE