Nuclear Theory·nucl-th

Thursday·October 6, 2022

9 papers—3 primary·6 cross-listed

04
[Submitted on 30 Sept 2022] (cross-list from hep-ph)
Hadron productions and jet substructures associated with $Z^{0} / γ$ in Pb+Pb collisions at the LHC
Shan-Liang Zhang🇨🇳 · Hongxi Xing🇨🇳 · Ben-Wei Zhang🇨🇳
We carry out a detailed study of medium modifications on $Z^{0}$ / $γ$ +hadron correlations as well as jet substructures in association with $Z^{0} / γ$ in Pb+Pb collisions with $s_{N N} = 5.02$ TeV at the LHC. We utilize the Linear Boltzmann transport (LBT) model to simulate the jet-medium interactions and medium response, and an extended cluster hadronization model to investigate the non-perturbative transition of quarks and gluons into final hadrons in heavy-ion collisions. Including hadronization effect, we can well describe $Z^{0} / γ$ +hadrons correlations and $Z^{0} / γ$ -tagged jet substructures in both p+p and Pb+Pb collisions simultaneously. Medium modification on jet profile and jet fragmentation functions indicate that particles carrying a large fraction of the jet momentum are generally closely aligned with the jet axis, whereas low-momentum particles are observed to have a much broader angular distribution relative to jet axis in Pb+Pb collisions due to jet-medium interactions. In particular, we find that $Z^{0} / γ$ -tagged hadron correlations are sensitive to the soft particles from the dense medium and medium response, while jet-substructures show weak dependence on those soft hadrons with only a fraction of them falling inside the jet area
Comments:
13pages, 11 figures
Subjects:
High Energy Physics — Phenomenology (hep-ph); Nuclear Theory (nucl-th)
arXiv:
2209.15336 [pdf]
SCPMA(2023)·5 citations
05
[Submitted on 4 Oct 2022] (cross-list from nucl-ex)
Charge radii of $^{55, 56}$ Ni reveal a surprisingly similar behavior at $N = 28$ in Ca and Ni isotopes
F. Sommer · K. König · D.M. Rossi · N. Everett · D. Garand · R.P. de Groote · J.D. Holt · P. Imgram · A. Incorvati · C. Kalman · A. Klose · J. Lantis and 15 other authors
Nuclear charge radii of $^{55, 56}$ Ni were measured by collinear laser spectroscopy. The obtained information completes the behavior of the charge radii at the shell closure of the doubly magic nucleus $^{56}$ Ni. The trend of charge radii across the shell closures in calcium and nickel is surprisingly similar despite the fact that the $^{56}$ Ni core is supposed to be much softer than the $^{48}$ Ca core. The very low magnetic moment $μ (^{55} Ni) = - 1.108 (20) μ_{N}$ indicates the impact of M1 excitations between spin-orbit partners across the $N, Z = 28$ shell gaps. Our charge-radii results are compared to \textit{ab initio} and nuclear density functional theory calculations, showing good agreement within theoretical uncertainties.
Subjects:
Nuclear Experiment (nucl-ex); Nuclear Theory (nucl-th)
arXiv:
2210.01924 [pdf]
PRL(2022)·55 citations
06
[Submitted on 5 Oct 2022] (cross-list from hep-ph)
Inverse mass ordering of light scalar mesons in the Nambu Jona-Lasinio model
Takahiro Saionji🇯🇵 · Daisuke Jido🇯🇵 · Masayasu Harada🇯🇵
The masses of the low-lying scalar mesons are investigated in the three-flavor Nambu Jona-Lasinio (NJL) model by treating the scalar mesons as composite objects of a quark and an antiquark. It is known that a simple $q ˉ q$ picture fails to reproduce so-called inverse mass ordering for the scalar mesons. Recently a new mechanism to reproduce the observed mass spectrum of the scalar mesons was proposed in a linear sigma model by introducing flavor symmetry breaking induced by the U(1) axial anomaly. Motivated by this proposal, we examine whether this new mechanism works also in the NJL model. By calculating the scalar meson masses, we find that the NJL model reproduces the observed mass ordering with sufficient strength of the new term. With this mechanism, it turns out that the constituent strange quark mass gets degenerate to that of the up and down quark if the inverse mass ordering is reproduced. We also discuss the scalar diquark masses to check the consistency of the degeneracy of the constituent quark masses with the light baryon masses.
Comments:
17 pages, 3 figures
Subjects:
High Energy Physics — Phenomenology (hep-ph); Nuclear Theory (nucl-th)
arXiv:
2210.01993 [pdf]
PTEP(2023)·3 citations
07
[Submitted on 5 Oct 2022] (cross-list from hep-ph)
Models of $J /Ψ$ photo-production reactions on the nucleon
T.-S. H. Lee🇺🇸 · S. Sakinah🇰🇷 · Yongseok Oh🇰🇷
The $J /Ψ$ photo-production reactions on the nucleon can provide information on the roles of gluons in determining the $J /Ψ$ -nucleon ( $J /Ψ$ -N) interactions and the structure of the nucleon. The information on the $J /Ψ$ -N interactions is needed to test lattice QCD (LQCD) calculations and to understand the nucleon resonances such as $N^{*} (P_{c})$ recently reported by the LHCb Collaboration. In addition, it is also needed to investigate the production of nuclei with hidden charms and to extract the gluon distributions in nuclei. The main purpose of this article is to review six reaction models of $γ + p \to J /Ψ + p$ reactions which have been and can be applied to analyze the data from Thomas Jefferson National Accelerator Facility (JLab). The formulae for each model are given and used to obtain the results to show the extent to which the available data can be described. The models presented include the Pomeron-exchange model of Donnachie and Landshoff (Pom-DL) and its extensions to include $J /Ψ$ -N potentials extracted from LQCD (Pom-pot) and to also use the constituent quark model (CQM) to account for the quark substructure of $J /Ψ$ (Pom-CQM). The other three models are developed from applying the perturbative QCD approach to calculate the two-gluon exchange using the generalized parton distribution (GPD) of the nucleon (GPD-based), two- and three-gluon exchanges using the parton distribution of the nucleon ( $2 g + 3 g$ ), and the exchanges of scalar ( $0^{++}$ ) and tensor ( $2^{++}$ ) glueballs within the holographic formulation (holog). The results of investigating the excitation of the nucleon resonances $N^{*} (P_{c})$ in the $γ + p \to J /Ψ + p$ reactions are also given.
Comments:
26 pages
Subjects:
High Energy Physics — Phenomenology (hep-ph); Nuclear Theory (nucl-th)
arXiv:
2210.02154 [pdf]
EPJA(2022)·22 citations
08
[Submitted on 5 Oct 2022] (cross-list from hep-ph)
Baryon anticorrelations and the Pauli principle in PYTHIA
Noe Demazure (ENS Lyon)🇫🇷 · Víctor González Sebastián (Wayne State U.)🇺🇸 · Felipe J. Llanes-Estrada (U. Complutense Madrid)🇪🇸
We present a computational investigation of a problem of hadron collisions from recent years, that of baryon anticorrelations. This is an experimental dearth of baryons near other baryons in phase space, not seen upon examining numerical Monte Carlo simulations. We have addressed one of the best known Monte Carlo codes, PYTHIA, to see what baryon (anti)correlations it produces, where they are originated at the string-fragmentation level in the underlying Lund model, and what simple modifications could lead to better agreement with data. We propose two ad-hoc alterations of the fragmentation code, a "one-baryon" and an "always-baryon" policies that qualitatively reproduce the data behaviour, i.e anticorrelation, and suggest that lacking Pauli-principle induced corrections at the quark level could be the culprit behind the current disagreement between computations and experiment.
Comments:
16 pages, 25 plots
Subjects:
High Energy Physics — Phenomenology (hep-ph); High Energy Physics — Experiment (hep-ex); Nuclear Theory (nucl-th)
arXiv:
2210.02358 [pdf]
Few Body Syst.(2023)·4 citations
09
[Submitted on 5 Oct 2022] (cross-list from hep-ph)
Linear scaling of lepton charge asymmetry in $W^{\pm}$ production in ultra-relativistic nuclear collisions
An-Ke Lei🇨🇳 · Dai-Mei Zhou🇨🇳 · Yu-Liang Yan🇨🇳 · Xiao-Ming Zhang🇨🇳 · Liang Zheng🇨🇳 · Du-Juan Wang🇨🇳 · Xiao-Mei Li🇨🇳 · Gang Chen🇨🇳 · Xu Cai🇨🇳 · Ben-Hao Sa🇨🇳
The lepton charge asymmetry in $W^{\pm}$ production in the nuclear collisions at $s_{NN} = 5.02$ TeV is investigated with a parton and hadron cascade model PACIAE. Recently published ALICE and the ATLAS data of lepton charge asymmetry are well reproduced. An interesting linear scaling behavior is observed in the lepton charge asymmetry as a function of the collision system valence quark number asymmetry among the different size of nuclear collision systems at $s_{NN} = 5.02$ TeV. This linear scaling behavior may serve as an additional constraint on the PDF (nPDF) extractions.
Comments:
6 pages, 4 figures. arXiv admin note: text overlap with arXiv:2201.09525
Subjects:
High Energy Physics — Phenomenology (hep-ph); Nuclear Theory (nucl-th)
arXiv:
2210.02422 [pdf]
Mod.Phys.Lett.A(2023)·1 citation

Affiliations

first authorsco-authorsvia INSPIRE

Hadron productions and jet substructures associated with Z0/γ in Pb+Pb collisions at the LHC

Charge radii of 55,56Ni reveal a surprisingly similar behavior at N=28 in Ca and Ni isotopes

Inverse mass ordering of light scalar mesons in the Nambu Jona-Lasinio model

Models of J/Ψ photo-production reactions on the nucleon

Baryon anticorrelations and the Pauli principle in PYTHIA

Linear scaling of lepton charge asymmetry in W± production in ultra-relativistic nuclear collisions

Affiliations

Hadron productions and jet substructures associated with $Z^{0} / γ$ in Pb+Pb collisions at the LHC

Charge radii of $^{55, 56}$ Ni reveal a surprisingly similar behavior at $N = 28$ in Ca and Ni isotopes

Models of $J /Ψ$ photo-production reactions on the nucleon

Linear scaling of lepton charge asymmetry in $W^{\pm}$ production in ultra-relativistic nuclear collisions