Late Leptogenesis from Radiative Soft Terms

Abstract

We point out that the so-called ``soft leptogenesis'' can occur at TeV scale if the $B$ term is generated through radiative corrections which involve two-loop diagrams with the gaugino exchange. This mechasnism requires the non-trivial CP phase, ${Im}(A m_{1/2}^*)\neq 0$, and can naturally explain the observed baryon asymmetry of the universe associated with the TeV scale seesaw mechanism. Such a low scale leptogenesis would be a promising option in view of the tight upper limit on the reheat temperature avoiding the gravitino problem in supergravity models.