PaperPanorama

Nuclear Theory·nucl-th

Monday·November 8, 2021

9 papers4 primary·5 cross-listed

  1. 01

    [Submitted on 5 Nov 2021]

    The Gluon Exchange Model in proton-nucleus collisions

    Marek Jeżabek🇵🇱 · Andrzej Rybicki🇵🇱

    We apply our recently formulated Gluon Exchange Model (GEM) to baryon production in proton-nucleus reactions involving N>1 proton-nucleon collisions. We propose a description scheme for the process of soft color octet (gluon) exchange, based on the assumption that probabilities to form an effective diquark are equal for all allowed pairs of quarks. The latter effective diquark can form either from two valence, one valence and one sea, or from two sea quarks. Consequently we calculate the probabilities for different color configurations involving diquarks of valence-valence, valence-sea and sea-sea type. These probabilities appear to depend on the number of exchanged gluons, which results in increasing baryon stopping as a function of the number of proton-nucleon collisions in the nucleus. As such, the nuclear stopping power appears to be governed by the emergence of new color configurations as a function of N rather than by the energy loss of the original valence diquark. The advantage of our approach lies in its high predictive power which makes it verifiable by the new, precise data on proton and neutron production from the CERN SPS. The latter verification, and a set of predictions for the N-dependence of the baryon stopping process, are included in the letter.

    Comments:
    15 pages, 4 figures
    Subjects:
    Nuclear Theory (nucl-th); High Energy Physics — Phenomenology (hep-ph)
    arXiv:
    2111.03401 [pdf]
    Acta Phys.Polon.B(2022)·1 citation
  2. 02

    [Submitted on 5 Nov 2021]

    Nuclear effects on the meson produced in the inclusive photonuclear reaction

    Swapan Das🇮🇳

    The hadronic properties of the meson produced in the inclusive photonuclear reaction have been investigated. The elementary reaction occurring in the nucleus is assumed as . The meson, while propagating through the nucleus, interacts with the nuclear particles, and therefore, the properties of the meson can be modified because of this interaction. Being a short-lived particle, the meson decays to various elementary particles, such as, , , .... etc. The invariant mass, i.e., the meson mass, distribution spectra have been calculated to extract the information about the parameters, viz., mass and width, of the meson in the nucleus. The calculated results have been compared with the data reported from Jefferson Laboratory.

    Comments:
    Preprint - 15 pages, 3 figures
    Subjects:
    Nuclear Theory (nucl-th)
    arXiv:
    2111.03449 [pdf]
    PRC(2021)·3 citations
  3. 03

    [Submitted on 5 Nov 2021]

    Multiple isovector pairing and seniority multi- algebras with isospin

    V.K.B. Kota · R. Sahu

    With nucleons occupying several shell model orbits, the isovector pair creation operator (creates a two particle state with angular momentum and isospin ) is no longer unique. Choosing it to be a sum of single- isovector pair creation operators each with a phase, there will be multiple pair algebras with isospin; with number of orbits, there will be algebras each with a corresponding complementary algebra [] that gives seniority and reduced isospin quantum numbers. Three applications of multiple algebras are presented demonstrating the usefulness of considering pairing algebras with general sign factors.

    Comments:
    10 pages, 1 table, 1 figure, to appear in Bulgarian Journal of Physics
    Subjects:
    Nuclear Theory (nucl-th)
    arXiv:
    2111.03521 [pdf]
    Bulg.J.Phys.(2021)·1 citation
  4. 04

    [Submitted on 5 Nov 2021]

    Pauli Blocking for a Relativistic Fermi Gas in Quasielastic Lepton Nucleus Scattering

    Arie Bodek🇺🇸

    The expressions for the overall effect of Pauli blocking in quasielastic (QE) lepton scattering from nuclear targets within the framework of the Relativistic Fermi Gas (RFG) given in several publications are incorrect. For example, the expressions published by Bell and Llewelyn Smith in 1972 are incorrect (probably a typographical error). The expressions for Pauli blocking presented in several subsequent publications including the paper of C.H. Llewelyn Smith in 1972 and the paper of Paschos and Yu in 2002 have the same error. Another example is a 1992 paper by Singh and Oset which has a different (probably also a typographical) error. Other papers such as the papers of Tsai in 1974 and Bosted and Mamyan in 2012 use the correct expressions. In this short preprint we review the geometrical derivation of the overall reduction of the QE cross sections due to Pauli blocking for electron and neutrino scattering for targets with equal numbers of neutrons and protons and for targets with unequal numbers of neutrons and protons and derive the correct expressions. However, we note that the effects of Pauli blocking within the framework of the RFG model are much larger than in other more realistic models of QE scattering such as superscaling or a spectral function approach.

    Comments:
    5 pages, 4 figures, 2 tables
    Subjects:
    Nuclear Theory (nucl-th); High Energy Physics — Phenomenology (hep-ph)
    arXiv:
    2111.03631 [pdf]
    11 citations

Affiliations

first authorsco-authorsvia INSPIRE