Baryogenesis

I review recent progress on the electroweak phase transition and baryogenesis, focusing on the minimal supersymmetric standard model as the source of new physics.

The cosmological baryon asymmetry is closely related to neutrino properties due to the non-perturbative sphaleron processes in the high-temperature symmetric phase of the standard model. We review some aspects of this connection with emphasis on cosmological bounds on neutrino masses, leptogenesis and possible implications for dark matter.

The sphaleron type solution in the electroweak theory, generalized to include the dilaton field, is examined. The solutions describe both the variarions of Higgs and Gauge fields inside the sphaleron and the shape of the dilaton cloud surrounding the sphaleron. Such a cloud is large and extends far outside. These phenomena may play an important role during the baryogenesis which probably took place in the Early Universe.

In this review article, we revisit the topic of baryogenesis, which is the physical process that generated the observed baryon asymmetry during the first stages of the primordial Universe. A viable theoretical explanation to understand and investigate the mechanisms underlying baryogenesis must always ensure that the Sakharov criteria are fulfilled. These essentially state the following: (i) baryon number violation; (ii) the violation of both C (charge conjugation symmetry) a...

The conventional baryogenesis mechanism is based on the one Higgs doublet within the standard model, at the electroweak scale $T\sim 100 GeV$. In this model the strong first order phase transition due to the spontaneous symmetry breaking imposes the folowing condition on the mass of the Higgs field: $m_H\lesssim 40 GeV$, which is contrary to the recently observed value $m_H\simeq 126 GeV$. In this paper we propose a baryogenesis mechanism within a two-Higgs-doublet model in w...

I give a synopsis, specifically aimed at nonexperts, of some of the recent developments in electroweak baryogenesis. The focus of the talk is on the present status of electroweak baryogenesis in supersymmetric models, since this is a plausible and realistic possibility that is currently being probed by experimental searches for the Higgs boson and the top squark. The question of whether it is viable to have a period of color-breaking during the electroweak phase transition is...

The generation of the observed baryon asymmetry may have taken place during the electroweak phase transition, thus involving physics testable at LHC, a scenario dubbed electroweak baryogenesis. In this paper we point out that the magnetic field which is produced in the bubbles of a first order phase transition endangers the baryon asymmetry produced in the bubble walls. The reason being that the produced magnetic field couples to the sphaleron magnetic moment and lowers the s...

We discuss the generation of the baryon asymmetry by a strong first order electroweak phase transition in the early universe, particularly in the context of the MSSM. This requires a thorough numerical treatment of the bubble wall profile in the case of two Higgs fields. CP violating complex particle masses varying with the Higgs field in the wall are essential. Since in the MSSM there is no indication of spontaneous CP violation around the critical temperature (contrary to t...

A generic prediction of models where supersymmetry is broken at scales within a few orders of magnitude of the weak scale and is fed down to the observable sector by gauge interactions is the existence of superconducting cosmic strings which carry baryon number. In this paper we propose a novel mechanism for the generation of the baryon asymmetry which takes place at temperatures much lower than the weak scale. Superconducting strings act like ``bags'' containing the baryon c...

In this work, we classify all the effective $U(1)$ symmetries and their associated Noether charges in the Standard Model (SM) and its minimal supersymmetric extension (MSSM) from the highest scale after inflation down to the weak scale. We then demonstrate that the discovery of the violation of baryon minus lepton number ($B-L$) which pinpoints to its violation in primordial Universe at any cosmic temperature above $30$ TeV will open up a new window of baryogenesis in these e...