B-L genesis by sliding inflaton

Abstract

We propose a new mechanism of lepton (L) number asymmetry generation,hence offer an explanation of matter-antimatter imbalance whena significant amount of baryon number is latertransformed from this L-number by known electroweak sphaleron mediated process.The basic theoretical framework is arecently proposed multiple scalar-tensor gravity that dynamically solvesthe cosmological constant problem.The L-asymmetry generation in one of two proposed scenarios is triggered by dynamical relaxation of scalar inflaton field towardsthe zero cosmological constant.CPT violation (C = charge conjugation, P = parity operation,T = time reversal) in the presence of a chemical potentialgives the necessary time arrow, and lepton number violating scattering in cosmic thermal mediumgenerates a net cosmological L-number via resonance formation.Another scenario is L-asymmetry generation fromevaporating primordial black holes.These proposed mechanisms do not require CP violating phasesin physics beyond the standard model:the new required physicsis existence of heavy Majorana leptons of masses 1015 ∼ 1017 GeV that realizes the seesaw mechanism.We identify the cosmological epoch of lepto-genesis in two scenarios, which may give the right amount of observed baryon to entropy ratio.It might even be possible to experimentally determine microscopic physics parameter,masses of three heavy Majorana leptonsby observing astrophysical footprints of primordial black hole evaporationat specified hole masses.