Nuclear Theory·nucl-th

Monday·January 27, 2020

16 papers—7 primary·9 cross-listed

01
[Submitted on 23 Jan 2020]
Dynamics of critical fluctuations: Theory -- phenomenology -- heavy-ion collisions
M. Bluhm🇫🇷 · M. Nahrgang🇨🇭 · A. Kalweit🇫🇷 · M. Arslandok🇩🇪 · P. Braun-Munzinger🇩🇪 · S. Floerchinger🇩🇪 · E.S. Fraga🇧🇷 · M. Gazdzicki🇵🇱 · C. Hartnack🇫🇷 · C. Herold🇹🇭 · R. Holzmann🇩🇪 · Iu. Karpenko🇫🇷 and 18 other authors
This report summarizes the presentations and discussions during the Rapid Reaction Task Force "Dynamics of critical fluctuations: Theory -- phenomenology -- heavy-ion collisions", which was organized by the ExtreMe Matter Institute EMMI and held at GSI, Darmstadt, Germany in April 2019. We address the current understanding of the dynamics of critical fluctuations in QCD and their measurement in heavy-ion collision experiments. In addition, we outline what might be learned from studying correlations in other physical systems, such as cold atomic gases.
Comments:
89 pages, 11 figures, report on an ExtreMe Matter Institute EMMI Rapid Reaction Task Force
Subjects:
Nuclear Theory (nucl-th); High Energy Physics — Phenomenology (hep-ph); Nuclear Experiment (nucl-ex)
arXiv:
2001.08831 [pdf]
NPA(2020)·126 citations
02
[Submitted on 24 Jan 2020]
Single $Λ_{c}^{+}$ hypernuclei within quark mean-field model
Linzhuo Wu🇨🇳 · Jinniu Hu🇨🇳 · Hong Shen🇨🇳
The quark mean-field (QMF) model is applied to study the single $Λ_{c}^{+}$ hypernuclei. The charm baryon, $Λ_{c}^{+}$ , is constructed by three constituent quarks, $u, d$ , and $c$ , confined by central harmonic oscillator potentials. The confinement potential strength of charm quark is determined by fitting the experimental masses of charm baryons, $Λ_{c}^{+}, Σ_{c}^{+}$ , and $Ξ_{cc}^{++}$ . The effects of pions and gluons are also considered to describe the baryons at the quark level. The baryons in $Λ_{c}^{+}$ hypernuclei interact with each other through exchanging the $σ, ω$ , and $ρ$ mesons between the quarks confined in different baryons. The $Λ_{c}^{+} N$ potential in the QMF model is strongly dependent on the coupling constant between $ω$ meson and $Λ_{c}^{+}$ , $g_{ω Λ_{c}^{+}}$ . When the conventional quark counting rule is used, i. e., $g_{ω Λ_{c}^{+}} = 2/3 g_{ω N}$ , the massive $Λ_{c}^{+}$ hypernucleus can exist, whose single $Λ_{c}^{+}$ binding energy is smaller with the mass number increasing due to the strong Coulomb repulsion between $Λ_{c}^{+}$ and protons. When $g_{ω Λ_{c}^{+}}$ is fixed by the latest lattice $Λ_{c}^{+} N$ potential, the $Λ_{c}^{+}$ hypernuclei only can exist up to $A \sim 50$ .
Comments:
26 pages, 6 figures, 7 tables, accepted to Phys. Rev. C
Subjects:
Nuclear Theory (nucl-th)
arXiv:
2001.08882 [pdf]
PRC(2020)·7 citations
03
[Submitted on 24 Jan 2020]
Resonances in Exotic $^{7}$ He Nucleus within the No-Core Shell Model
I. A. Mazur · A. M. Shirokov · I. J. Shin · A. I. Mazur · Y. Kim · P. Maris · J. P. Vary
We present results of calculations of $n -^{6} He$ elastic scattering phase shifts and resonances in $^{7} He$ . The calculations utilize the SS-HORSE method combined with ab initio no-core shell model calculations of the $^{7} He$ and $^{6} He$ nuclei with Daejeon16 and the JISP16 $N N$ interactions.
Comments:
Final version of the paper published in Proceedings of the International Conference 'Nuclear Theory in the Supercomputing Era - 2018' (NTSE-2018), Daejeon, South Korea, October 29 - November 2, 2018. Pacific National University, Khabarovsk, Russia, 2019, p. 310. 9 pages, 4 figures
Subjects:
Nuclear Theory (nucl-th)
arXiv:
2001.08898 [pdf]
6 citations
04
[Submitted on 24 Jan 2020]
Modeling neutrino-nucleus interaction at intermediate energies
R. González-Jiménez🇧🇪 · N. Jachowicz🇧🇪 · A. Nikolakopoulos🇧🇪 · J. Nys🇧🇪 · T. Van Cuyck🇧🇪 · N. Van Dessel🇧🇪 · K. Niewczas🇧🇪 · V. Pandey🇺🇸
We present the current status of the research activities of the Ghent group on neutrino-nucleus interactions. These consist in the modeling of some of the relevant neutrino-nucleus reaction channels at intermediate energies: low-energy nuclear excitations, quasielastic scattering, two-nucleon knockout processes and single-pion production. The low-energy nuclear excitations and the quasielastic peak are described using a Hartree-Fock-CRPA (continuum random phase approximation) model that takes into account nuclear long-range correlations as well as the distortion of the outgoing nucleon wave function. We include two-body current mechanisms through short-range correlations and meson-exchange currents. Their influence on one- and two-nucleon knockout responses is computed. Bound and outgoing nucleons are treated within the same mean-field framework. Finally, for modeling of the neutrino-induced single-pion production, we use a low-energy model that contains resonances and the background contributions required by chiral symmetry. This low-energy model is combined with a Regge approach into a Hybrid model, which allows us to make predictions beyond the resonance region.
Comments:
Proceedings of the 19th International Workshop on Neutrinos from Accelerators-NuFact2017, 25-30 September, 2017, Uppsala University, Sweden
Subjects:
Nuclear Theory (nucl-th)
arXiv:
2001.08958 [pdf]
PoS(2017)·2 citations
05
[Submitted on 24 Jan 2020]
Peculiarity of the $^{12}$ C $(0^{+})$ and $^{12}$ C $(2^{+})$ energy spectrum in a 3 $α$ model
E.M. Tursunov · I. Mazumdar
Lowest energy spectrum of the $^{12}$ C nucleus is analyzed in the 3 $α$ cluster model with a deep $α α$ -potential of Buck, Friedrich and Wheatley with Pauli forbidden states in the $S$ and $D$ waves. The direct orthogonalization method is applied for the elimination of the 3 $α$ -Pauli forbidden states. The effects of possible first order quantum phase transition are shown in the lowest $^{12}$ C( $0_{1}^{+})$ and $^{12}$ C( $2_{1}^{+})$ states from weakly bound phase to a deep phase. The ground and lowest $2^{+}$ states of the $^{12}$ C nucleus in the deep phase are created by the critical eigen states of the Pauli projector for the $0^{+}$ and $2^{+}$ three-alpha functional spaces, respectively.
Comments:
13 pages, 2 figures
Subjects:
Nuclear Theory (nucl-th); Nuclear Experiment (nucl-ex)
arXiv:
2001.08995 [pdf]
Phys.Atom.Nucl.(2022)·9 citations
06
[Submitted on 24 Jan 2020]
Parity- and time-reversal-violating nuclear forces
J. de Vries🇺🇸 · E. Epelbaum🇩🇪 · L. Girlanda🇮🇹 · A. Gnech🇮🇹 · E. Mereghetti🇺🇸 · M. Viviani🇮🇹
Parity-violating and time-reversal conserving (PVTC) and parity-violating and time-reversal-violating (PVTV) forces in nuclei form only a tiny component of the total interaction between nucleons. The study of these tiny forces can nevertheless be of extreme interest because they allow to obtain information on fundamental symmetries using nuclear systems. The PVTC interaction derives from the weak interaction between the quarks inside nucleons and nuclei and the study of PVTC effects opens a window on the quark-quark weak interaction. The PVTV interaction is sensitive to more exotic interactions at the fundamental level, in particular to strong CP violation in the Standard Model Lagrangian, or even to exotic phenomena predicted in various beyond-the-Standard-Model scenarios. The presence of these interactions can be revealed either by studying various asymmetries in polarized scattering of nuclear systems, or by measuring the presence of non-vanishing permanent electric dipole moments of nucleons, nuclei and diamagnetic atoms and molecules. In this contribution, we review the derivation of the nuclear PVTC and PVTV interactions within various frameworks. We focus in particular on the application of chiral effective field theory, which allows for a more strict connection with the fundamental interactions at the quark level. We investigate PVTC and PVTV effects induced by these potential on several few-nucleon observables, such as the longitudinal asymmetry in proton-proton scattering and radiative neutron-proton capture, and the electric dipole momentsof the deuteron and the trinucleon system.
Comments:
68 pages, contribution to Frontiers in Physics
Subjects:
Nuclear Theory (nucl-th); High Energy Physics — Phenomenology (hep-ph); Nuclear Experiment (nucl-ex)
arXiv:
2001.09050 [pdf]
Front.in Phys.(2020)·54 citations
07
[Submitted on 24 Jan 2020]
Hydrodynamic generators in relativistic kinetic theory
Mike McNelis🇺🇸 · Ulrich Heinz🇺🇸
We resum the non-equilibrium gradient corrections to a single-particle distribution function evolved by the Boltzmann equation in the relaxation time approximation (RTA). We first study a system undergoing Bjorken expansion and show that, for a constant relaxation time, the exact solution of the RTA Boltzmann equation at late times (i.e. after the decay of non-hydrodynamic modes) generates the Borel resummed Chapman-Enskog series. Extending this correspondence to systems without Bjorken symmetry, we construct a (3+1)-dimensional hydrodynamic generator for RTA kinetic theory, which is an integral representation of the Chapman-Enskog series in the limit of vanishing non-hydrodynamic modes. Relaxing this limit we find at earlier times a set of non-hydrodynamic modes coupled to the Chapman-Enskog expansion. Including the dynamics of these non-hydrodynamic modes is shown to control the emergence of hydrodynamics as an effective field theory description of non-equilibrium fluids, which works well even for far-off-equilibrium situations where the Knudsen number is initially large.
Subjects:
Nuclear Theory (nucl-th)
arXiv:
2001.09125 [pdf]
PRC(2020)·15 citations

Affiliations

first authorsco-authorsvia INSPIRE

Dynamics of critical fluctuations: Theory -- phenomenology -- heavy-ion collisions

Single Λc+​ hypernuclei within quark mean-field model

Resonances in Exotic 7He Nucleus within the No-Core Shell Model

Modeling neutrino-nucleus interaction at intermediate energies

Peculiarity of the 12C(0+) and 12C(2+) energy spectrum in a 3α model

Parity- and time-reversal-violating nuclear forces

Hydrodynamic generators in relativistic kinetic theory

Affiliations

Single $Λ_{c}^{+}$ hypernuclei within quark mean-field model

Resonances in Exotic $^{7}$ He Nucleus within the No-Core Shell Model

Peculiarity of the $^{12}$ C $(0^{+})$ and $^{12}$ C $(2^{+})$ energy spectrum in a 3 $α$ model