November 25, 1999
We discuss the possibility of generating the baryon asymmetry of the Universe when the temperature of the Universe is much below the electroweak scale. In our model the evaporation of primordial black holes or the decay of massive particles re-heats the surrounding plasma to temperatures above the electroweak transition temperature leading to the restoration of electroweak symmetry locally. The symmetry is broken again spontaneously as the plasma cools and a baryon asymmetry ...
June 30, 2022
We discuss electroweak baryogenesis in aligned two Higgs doublet models. It is known that in this model the severe constraint from the experimental results for the electron electric dipole moment can be avoided by destructive interference among CP-violating effects in the Higgs sector. In our previous work, we showed that the observed baryon number in the Universe can be explained without contradicting current available data in a specific scenario in the same model. We here f...
April 15, 1994
We investigate an extension of the standard model with a second Higgs doublet, showing a two stage phase transition. Wash-out of a baryon asymmetry after the phase transition can be easily avoided in this class of models. B+L transitions are more strongly suppressed in the intermediate phase than in the high temperature symmetric phase,however. Therefore, it becomes more difficult if not impossible to generate a sufficient baryon asymmetry during the phase transition.
March 27, 1998
Contrary to naive cosmological expectations, all evidence suggests that the universe contains an abundance of matter over antimatter. This article reviews the currently popular scenario in which testable physics, present in the standard model of electroweak interactions and its modest extensions, is responsible for this fundamental cosmological datum. A pedagogical explanation of the motivations and physics behind electroweak baryogenesis is provided, and analytical approache...
August 28, 1998
We propose a new baryosymmetric mechanism for baryogenesis which takes place at the QCD scale and is based on the existence of domain walls separating the metastable vacua from the lowest energy vacuum. The walls acquire fractional negative and positive baryon charges, while the observed baryon asymmetry is due to a non-zero value of the $ \theta $ angle at the temperatures near the QCD chiral phase transition. The regions of metastable vacuum bounded by walls carry a negativ...
May 7, 1998
A brief review of the fundamental ideas behind electroweak baryogenesis is presented. Since a successful implementation of these ideas requires an extension of the minimal standard model, I comment on the necessary physics and how experimental constraints make these scenarios testable at the LHC, and perhaps at existing colliders.
June 22, 2021
Recently Dolgov and Pozdnyakov proposed a new baryogenesis mechanism in which baryon asymmetry is produced without violating baryon number at the Lagrangian level. In this scenario, baryon asymmetry is generated by absorption of a new particle X carrying baryon number onto Primordial Black Holes (PBHs). Assuming CP-violation, the particle X is absorbed at a different rate than the antiparticle $\bar{X}$, producing an asymmetry in the baryonic number. We independently test thi...
October 26, 2004
New fermions, strongly coupled to the Standard Model Higgs boson provide a well motivated extension of the Standard Model (SM). In this work we show that, once new physics at heavier scales is added to stabilize the Higgs potential, such an extension of the SM can strengthen the first order electroweak phase transition and make the electroweak baryogenesis mechanism feasible. We propose a SM extension with TeV Higgsinos, Winos and Binos that satisfy the following properties: ...
October 8, 2016
We propose a new scenario of the baryogenesis from primordial black holes (PBH). Assuming presence of microscopic baryon (or lepton) number violation and a CP violating operator such as $\partial_\alpha F(\mathcal{R_{....}} ) J^\alpha$, where $F(\mathcal{R_{....}})$ is a scalar function of the Riemann tensor, time evolution of an evaporating black hole generates baryonic (leptonic) chemical potential at the horizon; consequently PBH enumerates asymmetric Hawking radiation bet...
December 27, 2019
Primordial black holes are produced in a minimal UV extension to the Higgs inflation with an included $R^2$ term. We show that for parameters consistent with Standard Model measurements and Planck observation results lead to $M_{\rm PBH} \in (10^{-16}, 10^{-15}) M_\odot$ primordial black holes with significant abundance, which may consist the majority of dark matter.