CP violation in the SUSY seesaw: leptogenesis and low energy

Abstract

We suppose that the baryon asymmetry is produced by thermal leptogenesis (with flavour effects), at temperatures ∼ 10 9 -10 10 GeV, in the supersymmetric seesaw with universal and real soft terms. The parameter space is restricted by assuming that ℓ α → ℓ β γ processes will be seen in upcoming experiments. We study the sensitivity of the baryon asymmetry to the phases of the lepton mixing matrix, and find that leptogenesis can work for any value of the phases. We also estimate the contribution to the electric dipole moment of the electron, arising from the seesaw, and find that it is (just) beyond the sensitivity of next generation experiments ( 10 −29 e cm). The fourteen dimensional parameter space is efficiently explored with a Monte Carlo Markov Chain, which concentrates on the regions of interest.

Supersymmetric mass spectra for gravitino dark matter with a high reheating temperature

“…Interestingly, the lower bound T (min) R = 1.9 · 10 9 GeV [13] found in the model with the largest possible CP asymmetries and optimal (small) washout approximately coincides with values of T R obtained in generic models predicting the correct baryon asymmetry, found with the Monte Carlo Markov chain techniques [14]. For some Yukawa textures T R > ∼ 10 10 GeV even may be required.…”

“…Therefore, our assumption about including the nonperturbative effects in the gluino annihilations ensures that the NLSP relic density calculated here is at worst an upper bound, so the claim that a given model satisfies the BBN bound is robust [65]. We can now calculate the final NLSP abundance from: 13) which can be used to evaluate the standard cosmological parameter 14) where the present entropy density is s 0 = 2889.2 cm −3 and the critical density is ρ c = 1.0539 · 10 −5 GeV cm −3 .…”

Nonzeroθ13and leptogenesis in a type-I seesaw model withA4symmetry

“…We then investigate the generation of lepton asymmetry from the decay of RH neutrinos within 'one flavor approximation' [27][28][29][30]. As previously stated, nonzero lepton asymmetry can be obtained once we include the next to leading order terms in the Yukawa sector.…”

“…(1 + tan 2 β)10 12 GeV (where tan β = v u /v d ), it does not distinguish between flavors, the so called 'one-flavor approximation' regime [27][28][29][30] is achieved. The CP-asymmetry generated by the out-of-equilibrium decay of each RH neutrinos (and sneutrinos) is given by [40][41][42][43][44][45][46] 1) whereŶ ν is the effective Yukawa coupling matrix for neutrinos in the basis where RH neutrino mass matrix M Rd is diagonal 2 .…”

Interplay of LFV and slepton mass splittings at the LHC as a probe of the SUSY seesaw

“…Having flavours play an important rôle in leptogenesis also means that both low-and high-energy CPV phases contribute to the CP asymmetry; however, the flavoured BAU can be accounted for exclusively with R phases (for any value of θ 13 , δ, ϕ 1 , ϕ 2 ) [105,109] -in other words even if the U MNS phases are measured, the BAU can have any value.…”