Nuclear Theory·nucl-th

Friday·February 10, 2023

9 papers—7 primary·2 cross-listed

01
Framework for phase transitions between the Maxwell and Gibbs constructions
Constantinos Constantinou🇮🇹 · Tianqi Zhao🇺🇸 · Sophia Han🇨🇳 · Madappa Prakash🇺🇸
By taking the nucleon-to-quark phase transition within a neutron star as an example, we present a thermodynamically consistent method to calculate the equation of state of ambient matter so that transitions that are intermediate to those of the familiar Maxwell and Gibbs constructions can be described. This method does not address the poorly known surface tension between the two phases microscopically (as, for example, in the calculation of the core pasta phases via the Wigner-Seitz approximation) but instead combines the local and global charge neutrality conditions characteristic of the Maxwell and Gibbs constructions, respectively. Overall charge neutrality is achieved by dividing the leptons to those that obey local charge neutrality (Maxwell) and those that maintain global charge neutrality (Gibbs). The equation of state is obtained by using equilibrium constraints derived from minimizing the total energy density. The results of this minimization are then used to calculate neutron star mass-radius curves, tidal deformabilities, equilibrium and adiabatic sound speeds, and nonradial $g$ -mode oscillation frequencies for several intermediate constructions. Various quantities of interest transform smoothly from their Gibbs structures to those of Maxwell as the local-to-total electron ratio $η$ , introduced to mimic the hadron-to-quark interface tension from $0$ (Gibbs) to $\infty$ (Maxwell), is raised from $0$ to $1$ . A notable exception is the $g$ -mode frequency for the specific case of $η = 1$ for which a gap appears between the quark and hadronic branches.
nucl-thastro-ph.HEgr-qcPRD(2023)·37 citations
02
Exotic Baryons in Hot Neutron Stars
Adamu Issifu🇧🇷 · Kauan D. Marquez🇧🇷 · Mateus R. Pelicer🇧🇷 · Débora P. Menezes🇧🇷
We study the nuclear isentropic equation of state for a stellar matter composed of nucleons, hyperons, and $Δ$ -resonances. We investigate different snapshots of the evolution of a neutron star, from its birth as a lepton-rich protoneutron star in the aftermath of a supernova explosion to a lepton-poor regime when the star starts cooling to a catalyzed configuration. We use a relativistic model within the mean-field approximation to describe the hot stellar matter and adopt density-dependent couplings adjusted by the DDME2 parameterization. We use baryon-meson couplings for the spin- $1/2$ baryonic octet and spin- $3/2$ decuplet determined in a unified manner relying on $SU (6)$ and $SU (3)$ symmetry arguments. We observe that $Λ$ is the dominant exotic particle in the star at different entropies for both neutrino-free and neutrino-trapped stellar matter. For a fixed entropy, the inclusion of new particles (hyperons and/or delta resonances) in the stellar matter decreases the temperature. Also, an increase in entropy per baryon ( $1 to 2$ ) with decreasing lepton number density ( $0.4 to 0.2$ ) leads to an increase in stellar radii and a decrease in its mass due to neutrino diffusion. In the neutrino transparent matter, the radii decrease from entropy per baryon $2$ to $T = 0$ without a significant change in stellar mass.
nucl-thhep-phMNRAS(2023)·22 citations
03
$0 ν β β$ -decay nuclear matrix elements in self-consistent Skyrme quasiparticle random phase approximation: uncertainty from pairing interaction
W.-L. Lv🇨🇳 · Y.-F. Niu🇨🇳 · D.-L. Fang🇨🇳 · J.-M. Yao🇨🇳 · C.-L. Bai🇨🇳 · J. Meng🇨🇳
The uncertainty in the nuclear matrix elements (NMEs) of $0 ν β β$ decay for $^{76}$ Ge, $^{82}$ Se, $^{128}$ Te, $^{130}$ Te, and $^{136}$ Xe in the self-consistent quasiparticle random phase approximation (QRPA) method is investigated by using eighteen Skyrme interactions supplemented with either a volume- or surface-type of pairing interactions. The NMEs for the isotopes concerned (except $^{136}$ Xe) are less sensitive to the particle-hole ( $p h$ ) interactions, while strongly dependent on the employed isovector particle-particle ( $pp$ ) pairing interactions even though the pairing strengths are optimized to the same pairing gap. The results indicate that a precise determination of the isovector $pp$ pairing interaction in the Skyrme energy density functional is of importance to reduce the uncertainty in the NMEs within the QRPA framework.
nucl-thPRC(2023)·13 citations
04
Strong correlation of the neutron star core-crust transition density with the $σ$ -meson mass via vacuum polarization
Niu Li🇨🇳 · Wei-Zhou Jiang🇨🇳 · Jing Ye🇨🇳 · Rong-Yao Yang🇨🇳 · Si-Na Wei🇨🇳
We study the neutron star core-crust transition density $ρ_{t}$ with the inclusion of the vacuum polarization in the dielectric function in the nonlinear relativistic Hartree approach (RHAn). It is found that the strong correlation between the $ρ_{t}$ and the scalar meson mass $m_{σ}$ strikingly overwhelms the uncertainty of the nuclear equation of state in the RHAn models, in contrast to the usual awareness that $ρ_{t}$ is predominantly sensitive to the isovector nuclear potential and symmetry energy. The accurate extraction of $ρ_{t}$ through the future gravitational wave measurements can thus provide a strong constraint on the longstanding uncertainty of $m_{σ}$ , which is of significance to better infer the vacuum property. As an astrophysical implication, it suggests that the correlation between $ρ_{t}$ and $m_{σ}$ is very favorable to reconcile the difficulty in reproducing the large crustal moment of inertia for the pulsar glitches with the well constrained symmetry energy.
nucl-thastro-ph.IMPLB(2023)·4 citations
05
Recoil contributions in neutron beta decay and their corrections to the correlation coefficients
Hui-Yun Cao · Hai-Qing Zhou
In this work, the recoil corrections to the correlation coefficients in the neutron beta decay with polarized neutron and electron are evaluated to order O(m_n^-2) in the Born approximation. Different from the usual calculations applied in the literatures where the phase space factor and the amplitude are expanded independently, we directly expand the full differential scattering cross section and then integrate the solid angles of the neutrino. Furthermore, the most general coupling forms in Wpn are kept in the calculation and the analytic expressions for the angular correlation coefficients are given. The numerical comparisons between the results by the different treatments of the phase space factor and the different choices of the coupling parameters are also presented. The results show that the careful treatment of the expansion on m_n^-1 and the inclusion of the general coupling forms are necessary when aiming to reach the precision 10^-5
nucl-thPRC(2024)·0 citations
06
Quarkyonic Mean Field Theory
Dyana C. Duarte🇧🇷 · Saul Hernandez-Ortiz🇺🇸 · Kie Sang Jeong🇫🇷 · Larry D. McLerran🇫🇷
We discuss mean field theory of Quarkyonic matter at zero temperature. We treat the nucleons with contact interactions in mean field approximation, discussing both vector and scalar mean field interactions. We treat the quarks without mean field vector interactions, but allow mass terms to be generated consistent from a scalar mean field consistent with the additive quark model for quark masses. Quarkyonic matter is composed of a shell of nucleons that under-occupy the total available phase space associated with the underlying quark degrees of freedom. The fully occupied Fermi sphere beneath this shell of nucleons at high densities is thought of as quarks, but when this fully occupied distribution of states first appears, although the phase space is filled, the matter is at low density. For the transition between this low density and high density saturated matter, we advocate a dual description of the fully filled Fermi sea in terms of hadrons, and make a phenomenological hypothesis for the equation of state of this matter. We then proceed to an example where the mean field interactions are all vector and only associated with the nucleons, ignoring the effects of mass change associated with the scalar interactions. Except for the effects of Pauli blocking, the nucleons and quarks do not interact. To get a reasonable transition to Quarkyonic matter the interaction of the quarks among themselves are assumed to be non-perturbative, and a simple phenomenological relation between quark Fermi energy and density is introduced.
nucl-thhep-phPRC(2023)·13 citations
07
Nonlocal optical potential with core excitation in $^{10} Be (d, p)^{11} Be$ and $^{11} Be (p, d)^{10} Be$ reactions
A. Deltuva · D. Jurčiukonis
We propose a new nonlocal form of the nucleon-nucleus optical potential and demonstrate its reliability. We extend the nonlocal potential to include the excitation of the nuclear core and develop energy-independent roton- $^{10} Be$ potential reasonably reproducing the experimental data at low energies. We apply the new potential to the study of deuteron stripping and pickup reactions $^{10} Be (d, p)^{11} Be$ and $^{11} Be (p, d)^{10} Be$ using rigorous three-body Faddeev-type equations for transition operators that are solved in the momentum-space partial-wave framework. The achieved description of the experimental data is considerably more successful as compared to previous studies with local potentials. The values of spectroscopic factors consistent with the data are determined, exhibiting only weak energy dependence. The results possibly indicate an increased predicting power of the proposed calculational scheme.
nucl-thnucl-exPLB(2023)·9 citations

Affiliations

first authorsco-authorsvia INSPIRE

Framework for phase transitions between the Maxwell and Gibbs constructions

Exotic Baryons in Hot Neutron Stars

0νββ-decay nuclear matrix elements in self-consistent Skyrme quasiparticle random phase approximation: uncertainty from pairing interaction

Strong correlation of the neutron star core-crust transition density with the σ-meson mass via vacuum polarization

Recoil contributions in neutron beta decay and their corrections to the correlation coefficients

Quarkyonic Mean Field Theory

Nonlocal optical potential with core excitation in 10Be(d,p)11Be and 11Be(p,d)10Be reactions

Affiliations

$0 ν β β$ -decay nuclear matrix elements in self-consistent Skyrme quasiparticle random phase approximation: uncertainty from pairing interaction

Strong correlation of the neutron star core-crust transition density with the $σ$ -meson mass via vacuum polarization

Nonlocal optical potential with core excitation in $^{10} Be (d, p)^{11} Be$ and $^{11} Be (p, d)^{10} Be$ reactions