Related papers: Baryon number violation, baryogenesis and defects …
In a model of supersymmetric SU(5) Grand Unification with a spatial dimension described by the orbifold $S^1/(Z_2 \times Z_2')$, proton decay is naturally suppressed at all orders. This is achieved by a suitable implementation of the…
We explore leptogenesis induced by the propagation of neutrinos in gravitational backgrounds that may occur in string theory. The first background is due to linear dilatons and the associated Kalb-Ramond field (axion) in four non-compact…
Within supersymmetric SU(5) GUT we suggest mechanisms for suppression of baryon number violating dimension five and six operators. The mechanism is based on the idea of split multiplets (i.e. quarks and leptons are not coming from a single…
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…
We address the problem of baryon number violation in Randall-Sundrum backgrounds and provide a solution leading to a stable light Kaluza--Klein fermion in warped GUT. This adds to the list of dark matter candidates which stability can…
We examine the structure of baryonic wakes in the cosmological fluid which would form behind GUT-scale cosmic strings at early times (redshifts z > 100) in a neutrino-dominated universe. We show, using simple analytical arguments as well as…
We investigate the spontaneous breaking of the Baryon (B) and Lepton (L) number at the TeV scale in supersymmetric models. A simple extension of the minimal supersymmetric standard model where B and L are spontaneously broken local gauge…
We discuss the possibility of relating the size and sign of the observed baryon asymmetry of the universe to CP violation observable at low energies, in a framework where the observed baryon asymmetry is produced by leptogenesis through out…
The nucleon decay is a significant phenomenon to verify grand unified theories (GUTs). For the precise prediction of the nucleon lifetime induced by the gauge bosons associated with the unified gauge group, it is important to include the…
We show that baryogenesis can arise from the cosmological evolution of a scalar field that governs CP-violating parameters, such as the Yukawa couplings and the theta terms of the Standard Model. During the big bang, this scalar may reach a…
In a simple extension of the minimal supersymmetric standard model, out-of-equilibrium decays of TeV scale exotic vector-like squarks may generate the baryon asymmetry of the universe. Baryon number and CP violation are present in the…
At the end of inflation the universe is frozen in a near zero-entropy state with energy density in a coherent scalar field and must be ``defrosted'' to produce the observed entropy and baryon number. We propose that the baryon asymmetry is…
It is known that limits on baryon-violating nucleon decays do not, in general, imply corresponding suppression of $n - \bar n$ transitions. In the context of a model with fermions propagating in higher dimensions, we investigate a related…
We study the scenario of baryogenesis through leptogenesis in higher-dimensional theories, in which the scale of quantum gravity is many orders of magnitude smaller than the usual Planck mass. The minimal realization of these theories…
The classical picture of GUT baryogenesis has been strongly modified by theoretical progress concerning two nonperturbative features of the standard model: the phase diagram of the electroweak theory, and baryon and lepton number changing…
Bounds on R-parity violating couplings in the supersymmetric standard model are reviewed, and some new bounds arising from non-observation of certain rare B-decays (such as $B \rightarrow K^+K^-$) are presented. The focus is on…
We propose in this paper a scenario of spontaneous baryogenesis in cosmological models of Quintessence by introducing a derivative coupling of the Quintessence scalar $Q$ to the baryon current $J_B^{\mu}$ or the current of the baryon number…
Baryon and lepton number are excellent low-energy symmetries of the Standard Model (SM) that tightly constrain the form of its extensions. In this paper we investigate the possibility that these accidental symmetries are violated in the…
In our previous work, we found new types of the cosmic string solutions in the Abelian-Higgs model with an enhanced $U(1)$ global symmetry. We dubbed those solutions as the compensated/uncompensated strings. The compensated string is…
We propose a new mechanism to generate baryons. Electroweak strings produced at the electroweak phase transition will introduce anomalous currents through interactions of the strings with the background electromagnetic field and through…