Nuclear Theory·nucl-th

Thursday·July 14, 2022

8 papers—5 primary·3 cross-listed

01
[Submitted on 13 Jul 2022]
Uncertainty Quantification for Neutrino Opacities in Core-Collapse Supernovae and Neutron Star Mergers
Zidu Lin🇺🇸 · Andrew W. Steiner🇺🇸 · Jerome Margueron🇫🇷
We perform an extensive study of the correlations between the neutrino-nucleon inverse mean free paths (IMFPs) and the underlying equation of states (EoSs). Strong interaction uncertainties in the neutrino mean free path are investigated in different density regimes. The nucleon effective mass, the nucleon chemical potentials, and the residual interactions in the medium play an important role in determining neutrino-nucleon interactions in a density-dependent manner. We study how the above quantities are constrained by an EoS consistent with (i) nuclear mass measurements, (ii) proton-proton scattering phase shifts, and (iii) neutron star observations. We then study the uncertainties of both the charged current and the neutral current neutrino-nucleon inverse mean free paths due to the variation of these quantities, using Hartree-Fock+random phase approximation method. Finally, we calculate the Pearson correlation coefficients between (i) the EoS-based quantities and the EoS-based quantities; (ii) the EoS-based quantities and the IMFPs; (iii) the IMFPs and the IMFPs. We find a strong impact of residual interactions on neutrino opacity in the spin and spin-isospin channels, which are not well constrained by current nuclear modelings.
Comments:
Change the figure styles; correct several typos in text; accepted by PRC
Subjects:
Nuclear Theory (nucl-th)
arXiv:
2207.05927 [pdf]
PRC(2023)·6 citations
02
[Submitted on 13 Jul 2022]
Impacts of anomaly on nuclear and neutron star equation of state based on a parity doublet model
Bikai Gao🇯🇵 · Takuya Minamikawa🇯🇵 · Toru Kojo🇯🇵 · Masayasu Harada🇯🇵
We examine the role of the $U (1)_{A}$ anomaly in a parity doublet model of nucleons which include the chiral variant and invariant masses. Our model expresses the $U (1)_{A}$ anomaly by the Kobayashi-Maskawa-'t\,Hooft (KMT) interaction in the mesonic sector. After examining the roles of the KMT term in vacuum, we discuss its impacts on nuclear equations of state (EOS). The $U (1)_{A}$ anomaly increases the masses of the $η^{'}$ and $σ$ mesons and enhances the chiral symmetry breaking. The $U (1)_{A}$ anomaly enlarges the energy difference between chiral symmetric and symmetry broken vacuum; in turn, the chiral restoration at high density adds a larger energy density (often referred as a bag constant) to EOSs than in the case without the anomaly, leading to softer EOSs. Including these $U (1)_{A}$ effects, we update the previously constructed unified equations of state that interpolate the nucleonic EOS at $n_{B} \leq 2 n_{0}$ ( $n_{0} = 0.16 f m^{- 3}$ : nuclear saturation density) and quark EOS at $n_{B} \geq 5 n_{0}$ . The unified EOS is confronted with the observational constraints on the masses and radii of neutron stars. The softening of EOSs associated with the $U (1)$ anomaly reduces the overall radii, relaxing the previous constraint on the chiral invariant mass $m_{0}$ . Including the attractive nonlinear $ρ$ - $ω$ coupling to improved estimates for the slope parameter in the symmetry energy, our new estimate is $400 MeV \leq m_{0} \leq 700 MeV$ , with $m_{0}$ smaller than our previous estimate by $\sim 200$ MeV.
Comments:
14 pages
Subjects:
Nuclear Theory (nucl-th)
arXiv:
2207.05970 [pdf]
PRC(2022)·26 citations
03
[Submitted on 13 Jul 2022]
Entropic destruction of heavy quarkonium in a rotating hot and dense medium from holography
Ping-ping Wu🇨🇳 · Zi-qiang Zhang🇨🇳 · Xiangrong Zhu🇨🇳
Previous studies have indicated that the peak of the quarkonium entropy at the deconfinement transition can be related to the entropic force which would induce the dissociation of heavy quarkonium. In this paper, we study the entropic force in a rotating hot and dense medium using AdS/CFT correspondence. It turns out that the inclusion of angular velocity increases the entropic force thus enhancing quarkonium dissociation, while chemical potential has the same effect. Furthermore, the results imply that the quarkonium dissociates easier in rotating medium compared to static case.
Comments:
7 pages, 6 figures, to be published in Chinese Physics C
Subjects:
Nuclear Theory (nucl-th)
arXiv:
2207.06122 [pdf]
CPC(2022)·7 citations
04
[Submitted on 13 Jul 2022]
Anomalous low-energy $E 2$ -related behavior in triaxial nuclei
Yu Zhang · Ying-Wen He · D. Karlsson · Chong Qi · Feng Pan · J. P. Draayer
The anomalous low-energy $E 2$ -related behavior of a triaxially-deformed nucleus bas been identified and analyzed based on the SU(3) algebraic theory within the framework of the interacting boson model. The results show striking features that include a $B (E 2; 4_{1}^{+} \to 2_{1}^{+}) / B (2_{1}^{+} \to 0_{1}^{+}) < 1.0$ transition rate ratio and a $E (4_{1}^{+}) / E (2_{1}^{+}) > 2.0$ excitation energy ratio that can be tracked back to a finite- $N$ effect, which in a large- $N$ limit of the theory yields normal results for a stable $γ$ -deformation. This description is shown to be able to explain observed $E 2$ anomalous phenomenon in neutron-deficient nuclei such as $^{172}$ Pt and $^{168}$ Os, and in so doing yields a deeper understanding of the physical features of a soft triaxially-deformed nucleus.
Subjects:
Nuclear Theory (nucl-th)
arXiv:
2207.06201 [pdf]
PLB(2022)·40 citations
05
[Submitted on 13 Jul 2022]
Shell-model description for the properties of the forbidden $β^{-}$ decay in the region "north-east" of $^{208}$ Pb
Shweta Sharma · Praveen C. Srivastava · Anil Kumar · Toshio Suzuki
In the present work, we report a comprehensive shell-model study of the $lo g f t$ values for the forbidden $β^{-}$ decay transitions in the north-east region of $^{208}$ Pb. For this we have considered $^{210 - 215}$ Pb $\to$ $^{210 - 215}$ Bi and $^{210 - 215}$ Bi $\to$ $^{210 - 215}$ Po transitions. We have performed shell-model calculation using KHPE interaction in valence shell 82-126 for protons and 126-184 for neutrons without any truncation. We have also calculated half-lives and Q-values for the concerned nuclei. Recently several $lo g f t$ values are observed corresponding to $β^{-}$ decay from (8 $^{-}$ ) isomeric state of $^{214}$ Bi $^{m}$ at CERN-ISOLDE facility [Phys. Rev. C {\bf 104}, 054301 (2021)], and for the first time we have reported shell-model results for these transitions.
Comments:
13 pages, 3 figures, 5 tables
Subjects:
Nuclear Theory (nucl-th)
arXiv:
2207.06259 [pdf]
PRC(2022)·20 citations

Affiliations

first authorsco-authorsvia INSPIRE

Uncertainty Quantification for Neutrino Opacities in Core-Collapse Supernovae and Neutron Star Mergers

Impacts of anomaly on nuclear and neutron star equation of state based on a parity doublet model

Entropic destruction of heavy quarkonium in a rotating hot and dense medium from holography

Anomalous low-energy E2-related behavior in triaxial nuclei

Shell-model description for the properties of the forbidden β− decay in the region "north-east" of 208Pb

Affiliations

Anomalous low-energy $E 2$ -related behavior in triaxial nuclei

Shell-model description for the properties of the forbidden $β^{-}$ decay in the region "north-east" of $^{208}$ Pb