Effect of nuclear magnetic distribution on thephoto production of longitudinally polarizedlepton-pairs in the field of Na2311 and Al2713 nuclei

In this work we treat the influence of the nuclear magnetic moment on the photo production of e - e+, ?- ?+, ?- ?+ i. e. l- l+, lepton pairs. We examine the process: ? + N(Ze, ?j ) ? N(Ze, ?j ) + l-(p- ) + l+(p+) of production of (l- l+) - pairs by cir?cularly polarized photons ?(p?) in the field of nucleus, N, having electric (coulomb) charge Ze, and magnetic dipole moment ?j, where j is the nuclear spin. Taking into account the longitudinal polarizations of the produced pairs, we calculate the differential cross-sections for the angular and energy distributions of the pair particles. We investigate the effect of the nuclear magnetic moment on the angular and energy distribution of the antilepton l+(e+,?+,?+), showing that the contribution the cross-section from the nuclear magnetic dipole moment rises considerably on going to high energies of incident photon and large emission angles of the pair particles. The results of calculations for Na2311 (j =1/2) and Al2713 - target nuclei, and for the three lepton pair types (e - e+, ?- ?+, ?- ?+) are presented graphically [1, 2].