Nuclear Theory·nucl-th

Monday·June 27, 2022

7 papers—4 primary·3 cross-listed

01
Quark anomalous magnetic moment leads to the inverse magnetic catalysis phenomena of chiral restoration and deconfinement phase transitions in $μ_{B} - T$ plane
Shijun Mao🇨🇳
The effect of quark anomalous magnetic moment (AMM) to chiral restoration and deconfinement phase transitions in baryon chemical potential-temperature $(μ_{B} - T)$ plane under magnetic fields is investigated in frame of a Pauli-Villars regularized PNJL model. It's found that the quark AMM plays the role of inverse catalysis to the phase transitions, and large quark AMM will change the magnetic catalysis phenomena of phase transitions to inverse magnetic catalysis in the whole $μ_{B} - T$ plane. For a fixed magnetic field, the critical temperature $T_{c}$ and critical baryon chemical potential $μ_{B}^{c}$ decreases with quark AMM. The stronger the magnetic field is, the inverse catalysis effect of AMM becomes more important. For a small AMM $κ = κ_{1}$ , it shows the magnetic catalysis effect for critical temperature $T_{c}$ at vanishing $μ_{B}$ with increasing magnetic field, and (inverse) magnetic catalysis effect for critical baryon chemical potential $μ_{B}^{c}$ at vanishing $T$ under (weak) strong magnetic field. At finite $T$ and $μ_{B}$ , there exist some crossings of the phase transition lines with different magnetic field. For a large AMM $κ = κ_{2}$ , we obtain the inverse magnetic catalysis effect in the whole $μ_{B} - T$ plane, and no crossings of phase transition lines happen.
nucl-thhep-phPRD(2022)·21 citations
02
Low-energy $^{7}$ Li( $n, γ$ ) $^{8}$ Li and $^{7}$ Be( $p, γ$ ) $^{8}$ B radiative capture reactions within the Skyrme Hartree-Fock approach
Le-Anh Nguyen · Minh-Loc Bui
The electromagnetic dipole transitions in $^{7}$ Be( $p, γ$ ) $^{8}$ B and $^{7}$ Li( $n, γ$ ) $^{8}$ Li reactions at the keV-energy region were analyzed simultaneously within the Skyrme Hartree-Fock potential model. The Skyrme Hartree-Fock calculation is adopted as a microscopic approach to obtain consistently the single-particle bound and scattering states in the calculation of the radial overlap function within the potential model. All non-resonant and resonant electromagnetic dipole transitions are taken into account. The electric dipole transitions are successfully described with the slightest adjustment. The resonant magnetic dipole transitions at $633$ keV and $2184$ keV of $^{7}$ Be( $p, γ$ ) $^{8}$ B reaction, and the one at $222$ keV of $^{7}$ Li( $n, γ$ ) $^{8}$ Li are also analyzed. The astrophysical $S_{17} (0)$ factor of $^{7}$ Be( $p, γ$ ) $^{8}$ B reaction is found to be $22.3$ eV\,b.
nucl-thPRC(2022)·9 citations
03
Fragment productions in DJBUU and SQMD: comparative study
Dae Ik Kim · Chang-Hwan Lee · Kyungil Kim · Youngman Kim · Sangyong Jeon
We study $^{208}$ Pb+ $^{40, 48}$ Ca reactions at $E_{beam}$ = 50, 100 AMeV with DJBUU and SQMD transport codes. We compare the large primary fragments from the two codes at the end of the simulation time. We observe that overall the two models produce similar fragments. However, we see a noticeable difference between DJBUU and SQMD at $E_{beam} = 100$ AMeV with the impact parameter $b$ = 0 fm and discuss this difference in terms of the difference in the equation of state adopted in the two models and the difference in stability inherent to the BUU-type and QMD-type models.
nucl-thJ.Korean Phys.Soc.(2022)·2 citations
04
Order-by-order Anisotropic Transport Coefficients of a Magnetised Fluid: a Chapman-Enskog Approach
Utsab Gangopadhyaya🇮🇳 · Victor Roy🇮🇳
We derive the first and second-order expressions for the shear, the bulk viscosity, and the thermal conductivity of a relativistic hot boson gas in a magnetic field using the relativistic kinetic theory within the Chapman-Enskog method. The order-by-order off-equilibrium distribution function is obtained in terms of the associate Laguerre polynomial with magnetic field-dependent coefficients using the relativistic Boltzmann-Uehling-Uhlenbeck transport equation. The order-by-order anisotropic transport coefficients are evaluated in powers of the dimensionless ratio of kinetic energy to the fluid temperature for finite magnetic fields. In a magnetic field, the shear viscosity (in all order) splits into five different coefficients. Four of them show a magnetic field dependence as seen in a previous study \cite{Ashutosh1} using the relaxation time approximation for the collision kernel. On the other hand, bulk viscosity, which splits into three components (in all order), is independent of the magnetic field. The thermal conductivity shows a similar splitting but is field-dependent. The difference in the first and second-order results are prominent for the thermal conductivities than the shear viscosity; moreover, the difference in the two results is most evident at low temperatures. The first and second-order results seem to converge rapidly for high temperatures.
nucl-thJHEP(2022)·3 citations

Affiliations

first authorsco-authorsvia INSPIRE

Quark anomalous magnetic moment leads to the inverse magnetic catalysis phenomena of chiral restoration and deconfinement phase transitions in μB​−T plane

Low-energy 7Li(n,γ)8Li and 7Be(p,γ)8B radiative capture reactions within the Skyrme Hartree-Fock approach

Fragment productions in DJBUU and SQMD: comparative study

Order-by-order Anisotropic Transport Coefficients of a Magnetised Fluid: a Chapman-Enskog Approach

Affiliations

Quark anomalous magnetic moment leads to the inverse magnetic catalysis phenomena of chiral restoration and deconfinement phase transitions in $μ_{B} - T$ plane

Low-energy $^{7}$ Li( $n, γ$ ) $^{8}$ Li and $^{7}$ Be( $p, γ$ ) $^{8}$ B radiative capture reactions within the Skyrme Hartree-Fock approach