Isovector Pairing Effect on Nuclear Moment of Inertia at Finite Temperature in N = Z Even–even Systems

Abstract

Expressions of temperature-dependent perpendicular (ℑ⊥) and parallel (ℑ‖) moments of inertia, including isovector pairing effects, have been established using the cranking method. They are derived from recently proposed temperature-dependent gap equations. The obtained expressions generalize the conventional finite-temperature BCS (FTBCS) ones. Numerical calculations have been carried out within the framework of the schematic Richardson model as well as for nuclei such as N = Z, using the single-particle energies and eigenstates of a deformed Woods–Saxon mean-field. ℑ⊥ and ℑ‖ have been studied as a function of the temperature. It has been shown that the isovector pairing effect on both the perpendicular and parallel moments of inertia is non-negligible at finite temperature. These correlations must thus be taking into account in studies of warm rotating nuclei in the N ≃ Z region.

Number-projected nuclear moment of inertia in the isovector pairing case within the Richardson model

“…The used values of the angular momentum j and its projection m for each level have been taken from Ref. [20] where they have been arbitrarily chosen.…”

“…However, only a few papers deal with the study of the np pairing effect on the moment of inertia (see e.g. [12][13][14][15][16][17][18][19][20]). In addition, in all the previously cited works dealing with the moment of inertia of N Z nuclei, the particle-number fluctuations, which are inherent to the BCS approach, are not taken into account although their importance was stressed in the like-particles pairing case.…”

Effect of the Particle-Number Symmetry Restoration on Root Mean Square Radii of Even–even Neutron-Deficient Nuclei in the Isovector Pairing Case

“…The pairing constants G tt ′ have been directly deduced from the "experimental" values of the gap parameters ∆ tt ′ (see Refs. [46][47][48].…”

Number projected isovector neutron–proton pairing effect in odd-mass nuclei

“…It is well established that the states (9) and (11) are not eigenstates of the particle-number operator. However, the particle-number symmetry may be restored using a particlenumber projection method.…”

“…[1][2][3][4][5][6][7][8][9][10][11][12][13][14][15][16][17]). Indeed, the region of N^Z medium mass nuclei is now accessible to experiments and this fact led to renewed interest of theoreticians for this kind of nuclei.…”