Nuclear Scissors with Pairing and Continuity Equation

Nuclear Scissors Mode with Pairing

The coupled dynamics of the scissors mode and the isovector giant quadrupole resonance are studied using a generalized Wigner function moments method taking into account pair correlations. Equations of motion for angular momentum, quadrupole moment and other relevant collective variables are derived on the basis of the time dependent Hartree-Fock-Bogoliubov equations. Analytical expressions for energy centroids and transitions probabilities are found for the harmonic oscillator model with the quadrupole-quadrupole residual interaction and monopole pairing force. Deformation dependences of ener…

Non-Scissors-Mode Behaviour of Isovector Magnetic Dipole Orbital Transitions Involving Isospin Transfer

We study the response of isovector orbital magnetic dipole (IOMD) transitions to the quadrupole-quadrupole ($Q \cdot Q$) interaction, to the isospin-conserving pairing interaction (ICP) and to combinations of both. We find qualitatively different behaviours for transitions in which the final isospin differs from the initial isospin versus cases where the two isospins are the same. For $N=Z$ even-even nuclei with $J^π=0^+, T=0$ ground states such as $^8Be$ and $^{20}Ne$, the summed $T=0 \to T=1$ IOMD from the ground state to all the $J=1, T=1$ states in the $0 \hbar ω$ space does not vanish whe…

通过单胶子交换螺旋度振幅和重整化群方程对颜色超导性进行分类

Classification of color superconductivity by one-gluon exchange helicity amplitudes and renormalization group equations

该研究通过计算单胶子交换螺旋度振幅并引入非相对论配对通道分类，发现OGE新吸引通道、修正传统配对图景，还揭示费米动量失配对颜色超导配对稳定性的影响，为夸克物质配对模式研究提供新视角。

Pairing dynamics in particle transport

We analyze the effect of pairing on particle transport in time-dependent theories based on the Hartree-Fock-Bogoliubov (HFB) or BCS approximations. The equations of motion for the HFB density matrices are unique and the theory respects the usual conservation laws defined by commutators of the conserved quantity with the Hamiltonian. In contrast, the theories based on the BCS approximation are more problematic. In the usual formulation of TDHF+BCS, the equation of continuity is violated and one sees unphysical oscillations in particle densities. This can be ameliorated by freezing the occupatio…

From hadrons to quarks in neutron stars: a review

We review the equation of state of matter in neutron stars from the solid crust through the liquid nuclear matter interior to the quark regime at higher densities. We focus in detail on the question of how quark matter appears in neutron stars, and how it affects the equation of state. After discussing the crust and liquid nuclear matter in the core we briefly review aspects of microscopic quark physics relevant to neutron stars, and quark models of dense matter based on the Nambu--Jona-Lasinio framework, in which gluonic processes are replaced by effective quark interactions. We turn then to …