Neutron-proton pairing effect on the proton-rich nuclei moment of inertiaD. Mokhtari1, I. Ami1, M. Fellah1, 2 and N.H. Allal1, 2
1 Laboratoire de Physique Théorique, Faculté de Physique, USTHB, BP. 32, El-Alia, 16111 Bab-Ezzouar, Algiers, Algeria
2 Centre de Recherche Nucléaire d'Alger, COMENA, 2 bd Frantz Fanon, BP. 399 Alger-Gare, Algiers, Algeria
Published online: 21 May 2008
The neutron-proton (n-p) pairing effect on the nuclear moment of inertia is studied within the BCS approximation in the isovector case. An analytical expression of the moment of inertia is established by means of the cranking model. This expression generalizes the usual BCS one (i.e. when only the pairing between like-particles is considered). The moment of inertia of N = Z even-even nuclei, for which experimental values are known, i.e., such as 32 ≤ A ≤ 80, has been numerically evaluated, with and without inclusion of the n-p pairing effect. The used single-particle and eigen-states are those of a deformed Woods-Saxon mean field. It turns out that the inclusion of the n-p pairing improves the obtained values when compared to the usual BCS approximation, since the average discrepancies with the experimental data are respectively 7% and 37%.
© CEA 2008