1305.7456 (Xinle Shang et al.)

Angle dependent Gap state in Asymmetric Nuclear Matter    [PDF]

Xinle Shang, Wei Zuo

We propose an axi-symmetric angle dependent gap (ADG) state with the broken rotational symmetry in isospin-asymmetric nuclear matter. In this state, the deformed Fermi spheres of neutron and proton increase the pairing probabilities along the axis of the symmetry breaking near the average Fermi surface. We find the state possesses of lower free energy and larger gap value than the angle-averaged gap state for large isospin asymmetry. These properties are mainly caused by the coupling of different m_{j} components of the gap. Furthermore, we find the transition from the ADG state to normal state is of second order and the state vanish at the critical isospin-asymmetry \alpha_{c} where the angle-averaged gap vanishes.

View original: http://arxiv.org/abs/1305.7456