In supergravity models (such as standard superstring constructions) that possess a Heisenberg symmetry, supersymmetry breaking by the inflationary vacuum energy does not lift flat directions at tree-level. One-loop corrections give small squared masses that are negative (∼ -g2H2/(4π)2) for all flat directions that do not involve the stop. After inflation, these flat directions generate a large baryon asymmetry; typically nB/S ∼ O(1). We consider mechanisms for suppressing this asymmetry to the observed level. These include dilution from inflaton or moduli decay, GUT non-flatness of the vev direction, and higher dimensional operators in both GUT models and the MSSM. We find that the observed BAU can easily be generated when one or more of these effects is present.
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Supersymmetric (SUSY) theories possess a unique and efficient mechanism for the generation of a cosmological baryon asymmetry through the decay of scalar fields along nearly Fand D-flat directions of the scalar potential, using baryon number violation * This work was supported in part by DoE grants DE-FG02-94ER-40823 and DE-AC03-76SF00098, and by NSF grants AST-91-20005 and PHY-95-14797 and by the Alfred P. Sloan Foundation.
This work was supported in part by the Director, Office of Energy Research, Office of High Energy and Nuclear Physics, Division of High Energy Physics of the U.S. Department of Energy under Contracts DE-FG02-94ER-40823 and DE-AC03-76SF00098, by NSF grants AST-91-20005 and PHY-95-14797 and by the Alfred E Sloan Foundation.