Supersymmetric origin of matter

Abstract

The Minimal Supersymmetric extension of the Standard Model (MSSM) can provide the correct neutralino relic abundance and baryon number asymmetry of the universe. Both may be efficiently generated in the presence of CP violating phases, light charginos and neutralinos, and a light top squark. Due to the coannihilation of the neutralino with the light stop, we find a large region of parameter space in which the neutralino relic density is consistent with WMAP and SDSS data. We perform a detailed study of the additional constraints induced when CP violating phases, consistent with the ones required for baryogenesis, are included. We explore the possible tests of this scenario from present and future electron Electric Dipole Moment (EDM) measurements, direct neutralino detection experiments, collider searches and the b → sγ decay rate. We find that the EDM constraints are quite severe and that electron EDM experiments, together with stop searches at the Tevatron and Higgs searches at the LHC, will provide a definite test of our scenario of electroweak baryogenesis in the next few years.

Resonant flavor oscillations in electroweak baryogenesis

“…Similar resonances were discussed previously in Refs. [18][19][20][21][22][23][24], but our present work establishes its true origin on more theoretically sound footing. The width and height of this resonance are controlled by the ratio L osc /L w for typical thermal modes.…”

“…Fig. 5 demonstrates in a consistent framework of flavor mixing the resonant baryogenesis regime previously discussed in the context of perturbative mass-insertions [18,19,23,24] or perturbative insertions of mass gradients [20][21][22], and places the origin of this resonance on a firmer theoretical footing.…”

“…[9], there is no CP-violating source for the diagonal densities. Furthermore, although there is a source for the off-diagonal densities, the different components of f ij are decoupled; CP violation in f 12,21 does not feed into f 11,22 . By rotating to the flavor basis, one has n L,R = ∓ sin 2θ…”

“…The remaining discrepancies may be due to effects missed by the ansatz Eq. (56) for the collision term, on which we comment in Appendix B, and due to neglecting the feedback of δf 11,22 to f 12 through the wall-induced source in Eq. (53), on which we comment in Appendix C. The most significant discrepancy, however, between the treatment of Ref.…”

“…Our work demonstrated -for the first time in a consistent framework -the resonant baryogenesis regime discussed in Refs. [18][19][20][21][22][23][24] and placed it on a more rigorous theoretical footing. Importantly, we showed that the resonance occurs when the flavor oscillation period is comparable to the variation scale of the background Higgs field.…”