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Nuclear Theory·nucl-th

Monday·June 4, 2018

5 papers—3 primary·2 cross-listed

All5Primary3Cross-lists2
  1. 01

    [Submitted on 1 Jun 2018]

    Large-cutoff behavior of local chiral effective field theory interactions

    I. Tews🇺🇸 · L. Huth🇩🇪 · A. Schwenk🇩🇪

    Interactions from chiral effective field theory have been successfully employed in a broad range of \textit{ab initio} calculations of nuclei and nuclear matter, but it has been observed that most results of few- and many-body calculations experience a substantial residual regulator and cutoff dependence. In this work, we investigate the behavior of local chiral potentials at leading order under variation of the cutoff scale for different local regulators. When varying the cutoff, we require that the resulting interaction produces no spurious bound states in the deuteron channel. We find that, for a particular choice of leading-order operators, nucleon-nucleon phase shifts and the deuteron ground-state energy converge to cutoff-independent plateaus, for all regulator functions we investigate. This observation may enable improved calculations with chiral Hamiltonians that also include three-nucleon interactions.

    Comments:
    10 pages, 6 figures, published version
    Subjects:
    Nuclear Theory (nucl-th)
    arXiv:
    1806.00233 [pdf]
    PRC(2018)·13 citations
  2. 02

    [Submitted on 1 Jun 2018]

    Comment on "Sensitivity of () Reactions to High - Momenta and the Consequences for Nuclear Spectroscopy Studies"

    A. Deltuva

    Using adiabatic distorted-wave approximation (ADWA) with nonlocal optical potentials (NLOP) for transfer reactions [G.W. Bailey, N.K. Timofeyuk, and J.A. Tostevin, Phys. Rev. Lett. 117, 162502 (2016)] reported strong sensitivity to the - force model. This sensitivity disappears in rigorous three-body Faddeev-type results. Some shortcomings of ADWA with NLOP are pointed out.

    Subjects:
    Nuclear Theory (nucl-th); Nuclear Experiment (nucl-ex)
    arXiv:
    1806.00298 [pdf]
    4 citations
  3. 03

    [Submitted on 1 Jun 2018]

    Momentum dependence of pion-induced meson production on nuclei near threshold

    E. Ya. Paryev🇷🇺

    We study the near-threshold pion-induced production of mesons off nuclei in the kinematical conditions of the HADES experiment, recently performed at GSI. The calculations have been performed within a collision model based on the nuclear spectral function. The model accounts for both the primary meson--proton and the secondary pion--nucleon production processes as well as the effects of the nuclear and nucleon mean-field potentials. We find that the primary reaction channel dominates in the production off C and W target nuclei in the HADES acceptance window at incident pion momentum of 1.7 GeV/c. We calculate the momentum dependence of the absolute and relative (transparency ratio) meson yields from the above direct channel. The calculations have been performed for this initial pion momentum allowing for different options for the absorption cross section and different scenarios for the in-medium mass shifts of the meson and secondary neutron, produced together with in this channel. We demonstrate that the transparency ratio for the mesons has, contrary to the absolute cross sections, an insignificant sensitivity to the meson and secondary neutron in-medium mass shifts at momenta studied in the HADES experiment. On the other hand, we show that there are measurable changes in the transparency ratio due to the absorption cross section, which means that such relative observable can be useful to help determine this cross section from the data taken in the HADES experiment.

    Comments:
    21 pages, 9 figures
    Subjects:
    Nuclear Theory (nucl-th); Nuclear Experiment (nucl-ex)
    arXiv:
    1806.00303 [pdf]
    CPC(2018)·12 citations
  4. 04

    [Submitted on 1 Jun 2018] (cross-list from nucl-ex)

    Phase transition dynamics for hot nuclei

    B. Borderie🇫🇷 · N. Le Neindre🇫🇷 · M.F. Rivet🇫🇷 · P. Désesquelles🇫🇷 · E. Bonnet🇫🇷 · R. Bougault🇫🇷 · A. Chbihi🇫🇷 · D. Dell'Aquila🇫🇷 · Q. Fable🇫🇷 · J.D. Frankland🇫🇷 · E. Galichet🇫🇷 · D. Gruyer🇫🇷 and 14 other authors

    An abnormal production of events with almost equal-sized fragments was theoretically proposed as a signature of spinodal instabilities responsible for nuclear multifragmentation in the Fermi energy domain. On the other hand finite size effects are predicted to strongly reduce this abnormal production. High statistics quasifusion hot nuclei produced in central collisions between Xe and Sn isotopes at 32 and 45 AMeV incident energies have been used to definitively establish, through the experimental measurement of charge correlations, the presence of spinodal instabilities. N/Z influence was also studied.

    Comments:
    16 pages, 4 figures
    Subjects:
    Nuclear Experiment (nucl-ex); Nuclear Theory (nucl-th)
    arXiv:
    1806.00252 [pdf]
    PLB(2018)·28 citations
  5. 05

    [Submitted on 31 May 2018] (cross-list from hep-ph)

    Multiplicity dependent distributions of identified particles in pp collisions at 7 TeV within HIJING/ v2.0 model

    V.Topor Pop🇨🇦 · M.Petrovici🇷🇴

    Effects of strong longitudinal color fields (SCF) on the identified (anti)particle transverse momentum () distributions in collision at = 7 TeV are investigated within the framework of the {\small HIJING/BB̄ v2.0} model. The comparison with the experiment is performed in terms of the correlation between mean transverse momentum () and multiplicity (N) of charged particles at central rapidity, as well as the ratios of the distributions to the one corresponding to the minimum bias (MB) pp collisions at the same energy, each of them normalized to the corresponding charged particle density, for high multiplicity \mbox{(HM, N_{ch}>100)} and low multiplicity \mbox{(LM, N_{ch}<100)} class of events. The theoretical calculations show that an increase of the strength of color fields (as characterized by the effective values of the string tension ), from = 2 GeV/fm to = 5 GeV/fm from LM to HM class of events, respectively, lead to a ratio at low and intermediate (i.e., \mbox{GeV/{\it c} GeV/{\it c}}) consistent with recent data obtained at LHC by the ALICE Collaboration.

    Comments:
    14 pages and 11 figures. arXiv admin note: text overlap with arXiv:1306.0885
    Subjects:
    High Energy Physics — Phenomenology (hep-ph); Nuclear Theory (nucl-th)
    arXiv:
    1806.00359 [pdf]
    PRC(2018)·3 citations

Affiliations

first authorsco-authorsvia INSPIRE