Nuclear Theory·nucl-th

Tuesday·January 25, 2022

10 papers—7 primary·3 cross-listed

01
[Submitted on 21 Jan 2022]
Rapidity dependence of initial state geometry and momentum correlations in p+Pb collisions
Bjoern Schenke🇺🇸 · Soeren Schlichting🇩🇪 · Pragya Singh🇩🇪
Event geometry and initial state correlations have been invoked as possible explanations of long range azimuthal correlations observed in high multiplicity p+p and p+Pb collisions. We study the rapidity dependence of initial state momentum correlations and event-by-event geometry in $s = 5.02 TeV$ p+Pb collisions within the 3+1D IP-Glasma model~\cite{Schenke:2016ksl}, where the longitudinal structure is governed by JIMWLK rapidity evolution of the incoming nuclear gluon distributions. We find that the event geometry is correlated across large rapidity intervals whereas initial state momentum correlations are relatively short range in rapidity. Based on our results, we discuss implications for the relevance of both effects in explaining the origin of collective phenomena in small systems.
Comments:
17 pages, 14 figures
Subjects:
Nuclear Theory (nucl-th); High Energy Physics — Phenomenology (hep-ph)
arXiv:
2201.08864 [pdf]
PRD(2022)·37 citations
02
[Submitted on 22 Jan 2022]
A theoretical overview of isospin and EOS effects in heavy-ion reactions at intermediate energies
Bao-An Li · Bao-Jun Cai · Lie-Wen Chen · Wen-Jie Xie · Jun Xu · Nai-Bo Zhang
The isospin dependence of in-medium nuclear effective interactions is a fundamental issue in nuclear physics and has broad ramifications in astrophysics. Its uncertainties, especially the difference of neutron-proton interactions in the isosinglet and isotriplet channels, affect significantly the density and momentum dependence of the isovector single-nucleon potential and nucleon-nucleon short-range correlation in neutron-rich matter. Consequently, the neutron-proton effective mass splitting and the density dependence of nuclear symmetry energy are still rather uncertain. Heavy-ion reactions especially those involving rare isotopes is a useful tool for probing the isospin dependence of nuclear effective interactions through (1) the neutron-skin in coordinate and proton-skin in momentum of the initial state of colliding nuclei, (2) the density and momentum dependence of especially the isovector nuclear mean-field as well as (3) the isospin dependence of in-medium nucleon-nucleon cross sections. Observations of neutron stars especially since GW1710817 have also helped us significantly in understanding the isospin dependence of nuclear effective interactions. {\it We summarize here a review talk on these issues given at the 2021 International Workshop on multi-facets of EOS and Clustering. For details we refer the readers to the original publications and references therein}.
Comments:
Proc. of the International Workshop on Multi-facets of EoS and Clustering, Caen, France, Nov. 23-26th, 2021
Subjects:
Nuclear Theory (nucl-th); High Energy Astrophysical Phenomena (astro-ph.HE); Nuclear Experiment (nucl-ex)
arXiv:
2201.09133 [pdf]
Nuovo Cim.C(2022)·8 citations
03
[Submitted on 23 Jan 2022]
$Υ$ and $η_{b}$ mass shifts in nuclear matter and the nucleus bound states
G. N. Zeminiani🇧🇷
The $Υ$ and $η_{b}$ as well as $B^{*}$ meson mass shifts (scalar potentials) are estimated for the first time in symmetric nuclear matter. The main interest is, whether or not the strengths of the bottomonium-nuclear matter and charmonium-nuclear matter interactions are similar or very different, in the range of a few tens of MeV at the nuclear matter saturation density. This is because, each ( $Υ, J /Ψ$ ) and ( $η_{c}, η_{b}$ ) meson group is usually assumed to have very similar properties based on the heavy charm and bottom quark masses. The estimate for the $Υ$ is made using an SU(5) effective Lagrangian density, by studying the $B B$ , $B B^{*}$ , and $B^{*} B^{*}$ meson loop contributions for the self-energy in free space and in nuclear medium. As a result, only the $B B$ meson loop contribution is included as our minimal prediction. As for the $η_{b}$ , is included only the $B B^{*}$ meson loop contribution in the self-energy, to be consistent with the minimal prediction for the $Υ$ . The in-medium masses of the $B$ and $B^{*}$ mesons appearing in the self-energy loops are calculated by the quark-meson coupling model. Form factors are used to regularize the loop integrals with a wide range of the cutoff mass values. The results suggest that both $Υ$ and $η_{b}$ should form bound states with a variety of nuclei considered in this study, for which the $Υ$ -nucleus and $η_{b}$ -nucleus bound state energies are calculated. The results also show an appreciable difference between the bottomonium-nuclear matter and charmonium-nuclear matter interaction strengths. Are also studied the $Υ$ and $η_{b}$ mass shifts in a heavy quark (heavy meson) symmetry limit. In addition, an initial study was done to investigate the influence of the choice of the form factor on our predictions.
Comments:
144 pages, 27 figures (50 .eps files for figures), Master's degree thesis
Subjects:
Nuclear Theory (nucl-th); High Energy Physics — Experiment (hep-ex); High Energy Physics — Phenomenology (hep-ph); Nuclear Experiment (nucl-ex)
arXiv:
2201.09158 [pdf]
5 citations
04
[Submitted on 24 Jan 2022]
Coupled-channels calculations for nuclear reactions: from exotic nuclei to superheavy elements
K. Hagino · K. Ogata · A.M. Moro
Atomic nuclei are composite systems, and they may be dynamically excited during nuclear reactions. Such excitations are not only relevant to inelastic scattering but they also affect other reaction processes such as elastic scattering and fusion. The coupled-channels approach is a framework which can describe these reaction processes in a unified manner. It expands the total wave function of the system in terms of the ground and excited states of the colliding nuclei, and solves the coupled Shrödinger equations to obtain the $S$ -matrix, from which several cross sections can be constructed. This approach has been a standard tool to analyze experimental data for nuclear reactions. In this paper, we review the present status and the recent developments of the coupled-channels approach. This includes the microscopic coupled-channels method and its application to cluster physics, the continuum discretized coupled-channels (CDCC) method for breakup reactions, the semi-microscopic approach to heavy-ion subbarrier fusion reactions, the channel coupling effects on nuclear astrophysics and syntheses of superheavy elements, and inclusive breakup and incomplete fusion reactions of weakly-bound nuclei.
Comments:
90 pages, 37 figures. Accepted for publication in Progress in Particle and Nuclear Physics
Subjects:
Nuclear Theory (nucl-th); Nuclear Experiment (nucl-ex)
arXiv:
2201.09512 [pdf]
PPNP(2022)·61 citations
05
[Submitted on 24 Jan 2022]
Neutron-deuteron scattering cross-sections with chiral $N N$ interactions using wave-packet continuum discretization
Sean B. S. Miller · Andreas Ekström · Kai Hebeler
In this work we present a framework that allows to solve the Faddeev equations for three-nucleon scattering using the wave-packet continuum-discretization method. We perform systematic benchmarks using results in the literature and study in detail the convergence of this method with respect to the number of wave packets. We compute several different elastic neutron-deuteron scattering cross-section observables for a variety of energies using chiral nucleon-nucleon interactions. For the interaction $N2LO_{opt}$ we find good agreement with data for nucleon scattering-energies $E_{Lab} \leq 70$ MeV and a slightly larger maximum of the neutron analyzing power $A_{y} (n)$ at $E_{Lab} = 10$ MeV and 21 MeV compared with other interactions. This work represents a first step towards a systematic inclusion of three-nucleon scattering observables in the construction of next-generation nuclear interactions.
Comments:
17 pages, 7 figures
Subjects:
Nuclear Theory (nucl-th)
arXiv:
2201.09600 [pdf]
PRC(2022)·16 citations
06
[Submitted on 24 Jan 2022]
Formulation of the Generator Coordinate Method with arbitrary bases
L.M. Robledo
The existing formalism used to compute the operator overlaps necessary to carry out generator coordinate method calculations using a set of Hartree- Fock- Bogoliubov wave functions, is generalized to the case where each of the HFB states are expanded in different arbitrary bases spanning different sub-space of the Hilbert space.
Comments:
5 pages, no figures
Subjects:
Nuclear Theory (nucl-th); Strongly Correlated Electrons (cond-mat.str-el)
arXiv:
2201.09611 [pdf]
PRC(2022)·12 citations
07
[Submitted on 24 Jan 2022]
Electromagnetic anomaly in the presence of electric and chiral magnetic conductivities in relativistic heavy-ion collisions
Irfan Siddique🇨🇳 · Shanshan Cao🇨🇳 · Uzma Tabassam🇵🇰 · Mohsin Saeed🇵🇰 · Muhammad Waqas🇨🇳
We study the spacetime evolution of electric $(E)$ and magnetic $(B)$ fields along with the electromagnetic anomaly $(E \cdot B)$ in the presence of electric ( $σ$ ) and chiral magnetic ( $σ_{χ}$ ) conductivities in Au+Au collisions at $s_{NN} = 200$ ~GeV. By comparing to the Lienard-Wiechert solutions with zero conductivities, we observe a symmetry breaking of the electromagnetic field in a conducting medium with respect to the reaction plane. The decay of the field is also significantly decelerated after the conductivities are introduced. Similar effects are also found for the dipole structure of $E \cdot B$ as well as the quadrupole structure of $(E \cdot B) B$ , which may finally affect the charge separation of the elliptic flow coefficient of hadrons observed in high-energy nuclear collisions.
Comments:
11 pages, 12 figures
Subjects:
Nuclear Theory (nucl-th); High Energy Physics — Phenomenology (hep-ph); Nuclear Experiment (nucl-ex)
arXiv:
2201.09634 [pdf]
PRC(2022)·14 citations

Affiliations

first authorsco-authorsvia INSPIRE

Rapidity dependence of initial state geometry and momentum correlations in p+Pb collisions

A theoretical overview of isospin and EOS effects in heavy-ion reactions at intermediate energies

Υ and ηb​ mass shifts in nuclear matter and the nucleus bound states

Coupled-channels calculations for nuclear reactions: from exotic nuclei to superheavy elements

Neutron-deuteron scattering cross-sections with chiral NN interactions using wave-packet continuum discretization

Formulation of the Generator Coordinate Method with arbitrary bases

Electromagnetic anomaly in the presence of electric and chiral magnetic conductivities in relativistic heavy-ion collisions

Affiliations

$Υ$ and $η_{b}$ mass shifts in nuclear matter and the nucleus bound states

Neutron-deuteron scattering cross-sections with chiral $N N$ interactions using wave-packet continuum discretization