Tests of low-scale leptogenesis in charged lepton flavour violation experiments

Abstract

We consider low-energy tests of low-scale leptogenesis based on the type I seesaw scenario with three right-handed singlet neutrinos νlR. In this scenario, successful leptogenesis is possible for quasi-degenerate in mass heavy Majorana neutrinos N1,2,3, M1,2,3≅M, |Mj−Mi|≪M, i≠j=1,2,3, heavy Majorana neutrino masses M∼(0.05−5×105) GeV, and Nj charged current and neutral current weak interaction couplings as large as O(10−2). We derive the constraints on the corresponding leptogenesis parameter space from the existing data from low-energy experiments, including the limits from the experiments on μ→eγ decay and on the rate of μ−e conversion in gold. We show also that the planned and upcoming experiments on charged lepton flavour violation with μ±, MEG II on the μ→eγ decay, Mu3e on μ→eee decay, Mu2e and COMET on μ−e conversion in aluminium and PRISM/PRIME on μ−e conversion in titanium, can probe significant region of the viable leptogenesis parameter space, and thus have a potential for a discovery. Experiments on τ→eee(μμμ) and τ→e(μ)γ decays (e.g., BELLE II) also can probe a part of the leptogenesis parameter space, although a relatively small one.