Nuclear Theory·nucl-th

Wednesday·June 29, 2022

10 papers—5 primary·5 cross-listed

01
[Submitted on 27 Jun 2022]
The hadronic nucleus-nucleus cross section and the nucleon size
Govert Nijs🇺🇸 · Wilke van der Schee🇨🇭
Even though the total hadronic nucleus-nucleus cross section is among the most fundamental observables, it has only recently been measured precisely for lead-lead collisions at the LHC. This measurement implies the nucleon width should be below 0.7 fm, which is in contradiction with all known state-of-the-art Bayesian estimates. We study the implications of the smaller nucleon width on quark-gluon plasma properties such as the bulk viscosity. The smaller nucleon width dramatically improves the description of several triple-differential observables.
Comments:
5 pages, 4 figures + Appendix. v2: added XeXe results. Trajectum can be downloaded at https://sites.google.com/view/govertnijs/trajectum, output files and plotting routines at http://wilkevanderschee.nl/
Subjects:
Nuclear Theory (nucl-th); High Energy Physics — Phenomenology (hep-ph); Nuclear Experiment (nucl-ex)
arXiv:
2206.13522 [pdf]
PRL(2022)·53 citations
02
[Submitted on 28 Jun 2022]
Impact of magnetic field on giant dipole resonance of $^{40}$ Ca using the EQMD model
Ya-Ting Cao · Xian-Gai Deng · Yu-Gang Ma
By taking into account the magnetic field in the extended quantum molecular dynamics model (EQMD), we analyzed its effects on giant dipole resonance (GDR) by studying the responses and strengths of the dipole moments. The selected system is the $^{40}$ Ca nucleus which is excited through the Coulomb interaction by $^{16}$ O. Particle acceleration term in Liénard-Wiechert potential is discussed which, however, has small impact on magnetic field. The peak energy, strength and width of GDR, temperature, and angular momentum of $^{40}$ Ca as a function of beam energy are investigated. It is found that the magnetic field enhances the peak energy, strength and width of GDR which is not only due to the temperature effects but also due to the enhancement of the angular momentum of nucleus. At beam energy {E} $>$ 200 MeV/nucleon, magnetic field maintains a constant value for the strength of GDR. The work sheds light on examining important roles of the magnetic field on nuclear structure in low-intermediate energy heavy-ion collisions.
Comments:
9 pages, 6 figures
Subjects:
Nuclear Theory (nucl-th); Nuclear Experiment (nucl-ex)
arXiv:
2206.13921 [pdf]
PRC(2022)·9 citations
03
[Submitted on 28 Jun 2022]
Hyperon productions from Au+Au collisions at $s_{N N}$ =200 GeV
Purabi Ghosh🇮🇳 · Sushant K. Singh🇮🇳 · Santosh K. Agarwalla🇮🇳 · Jajati K. Nayak🇮🇳
We evaluate centrality dependence of hyperon, $Λ, Ξ, Ω$ and $K$ meson yields from Au+Au collisions at $s_{N N}$ =200 GeV using rate equation and compare with experimental observations. An increase in the yield per participating nucleon is observed with centrality. Higher rate of multistrange productions compared to single-strange are also observed in case of central collisions. Using rate equation or momentum integrated Boltzmann equation we discuss the yield microscopically which are then normalised with thermal pions to get the yield ratio,( $H_{s} + H_{s} ˉ$ )/( $π^{+} + π^{-}$ ) at various centralities. We have also evaluated the relative yield of anti hyperons per participant at various centralities and compared with observations made at RHIC. Increase in the rate of $Ξ$ yield compared to $Λ$ is realised in most central collisions. We find multi strange $Ξ, Ω$ freeze-out at a temperature very close to $T_{c}$ and $Λ, K$ do little later.
Comments:
12 pages, 5 figures
Subjects:
Nuclear Theory (nucl-th); High Energy Physics — Experiment (hep-ex); High Energy Physics — Phenomenology (hep-ph); Nuclear Experiment (nucl-ex)
arXiv:
2206.13986 [pdf]
0 citations
04
[Submitted on 28 Jun 2022]
Microscopic calculation of the $β^{-}$ decays of $^{151}$ Sm, $^{171}$ Tm, and $^{210}$ Pb with implications to detection of the cosmic neutrino background
Joel Kostensalo🇫🇮 · Jenni-Mari Kotila🇫🇮 · Jouni Suhonen🇫🇮
The electron spectral shapes corresponding to the low- $Q$ $β^{-}$ -decay transitions $^{151}$ Sm $(5/ 2_{g.s.}^{-}) \to^{151} Eu (5/ 2_{g.s.}^{+})$ , $^{151}$ Sm $(5/ 2_{g.s.}^{-}) \to^{151} Eu (7/ 2_{1}^{+})$ , $^{171}$ Tm $(1/ 2_{g.s.}^{+}) \to^{171} Yb (1/ 2_{g.s.}^{-})$ , $^{171}$ Tm $(1/ 2_{g.s.}^{+}) \to^{171} Yb (3/ 2_{1}^{-})$ , $^{210} Pb (0_{g.s.}^{+}) \to^{210} Bi (1_{g.s.}^{-})$ , and $^{210} Pb (0_{g.s.}^{+}) \to^{210} Bi (0_{1}^{-})$ have been computed using beta-decay theory with several refinements for these first-forbidden nonunique (ff-nu) $β^{-}$ transitions. These ff-nu $β^{-}$ transitions have non-trivial electron spectral shapes with transition nuclear matrix elements (NMEs) computed by using the microscopic Interacting Boson-Fermion Model (IBFM-2) for the decays of $^{151}$ Sm and $^{171}$ Tm, and the nuclear shell model (NSM) for the decay of $^{210}$ Pb. Within the respective $Q$ windows, the computed ff-nu electron spectral shapes deviate maximally at sub-percent level from the universal allowed shape, except for the transition $^{210} Pb (0_{g.s.}^{+}) \to^{210} Bi (1_{g.s.}^{-})$ , where the maximal deviation is some 2.7 $%$ . This confirms that the so-called $ξ$ approximation is fairly good for most of these low- $Q$ $β^{-}$ transitions and thus the allowed shape is a rather good first approximation. Our computed spectral shapes could be of interest for experiments aiming to measure the cosmic neutrino background (C $ν$ B), like the PTOLEMY experiment. We have also derived C $ν$ B cross sections for the ground-state transitions of the considered nuclei at the $β$ endpoint. Our findings indicate that more work on the atomic mismatch correction is needed in the future in order to extract reliable and precise C $ν$ B cross sections for any nuclear target.
Subjects:
Nuclear Theory (nucl-th)
arXiv:
2206.14010 [pdf]
PLB(2023)·5 citations
05
[Submitted on 28 Jun 2022]
A reassessment of nuclear effects in muonic deuterium using pionless effective field theory at N3LO
Vadim Lensky (JGU Mainz)🇩🇪 · Franziska Hagelstein (JGU Mainz and PSI Villigen)🇩🇪 · Vladimir Pascalutsa (JGU Mainz)🇩🇪
We provide a systematic assessment of the order- $α^{5}$ nuclear contributions to the Lamb shift of muonic deuterium, including the accompanying radiative corrections due to vacuum polarization, up to next-to-next-to-next-to-leading order (N3LO) within the pionless effective field theory (EFT). We also evaluate higher-order corrections due to the single-nucleon structure, which are expected to be the most important corrections beyond N3LO. We find a correlation between the deuteron charge and Friar radii, which can be useful to judge the quality of charge form factor parametrisations. We refine the theoretical description of the $2 γ$ -exchange contribution, especially in the elastic contribution and the radiative corrections, ameliorating the original discrepancy between theory and experiment in the size of $2 γ$ -exchange effects. Based on the experimental Lamb shift of muonic deuterium, we obtain the deuteron charge radius, $r_{d} (μ D) = 2.12763 (13)_{exp} (77)_{theory}$ ~fm, which is consistent with (but less precise than) the value obtained by combining the H-D isotope shift with the muonic hydrogen Lamb shift. The theory uncertainty is evaluated using a Bayesian procedure and is dominated by the truncation of the pionless EFT series.
Comments:
8 pages, 4 figures, minor changes and corrections, references added, matches published version
Subjects:
Nuclear Theory (nucl-th); High Energy Physics — Phenomenology (hep-ph); Nuclear Experiment (nucl-ex); Atomic Physics (physics.atom-ph)
arXiv:
2206.14066 [pdf]
PLB(2022)·8 citations

Affiliations

first authorsco-authorsvia INSPIRE

The hadronic nucleus-nucleus cross section and the nucleon size

Impact of magnetic field on giant dipole resonance of 40Ca using the EQMD model

Hyperon productions from Au+Au collisions at sNN​​=200 GeV

Microscopic calculation of the β− decays of 151Sm, 171Tm, and 210Pb with implications to detection of the cosmic neutrino background

A reassessment of nuclear effects in muonic deuterium using pionless effective field theory at N3LO

Affiliations

Impact of magnetic field on giant dipole resonance of $^{40}$ Ca using the EQMD model

Hyperon productions from Au+Au collisions at $s_{N N}$ =200 GeV

Microscopic calculation of the $β^{-}$ decays of $^{151}$ Sm, $^{171}$ Tm, and $^{210}$ Pb with implications to detection of the cosmic neutrino background