Fermion masses and mixings, Leptogenesis and Baryon number violation in Pati-Salam model

Abstract

In this work we study a predictive model based on a partially unified theory possessing the gauge symmetry of the Pati-Salam group, SU (2) L × SU (2) R × SU (4) C supplemented by a global Peccei-Quinn symmetry, U (1) P Q . A comprehensive analysis of the Higgs potential is carried out in a minimal set-up. The assumed Peccei-Quinn symmetry along with solving the strong CP problem, can provide axion as the dark matter candidate. This minimal set-up with limited number of Yukawa parameters can successfully incorporate the hierarchies in the charged fermion masses and mixings. The automatic existence of the heavy Majorana neutrinos generate the extremely small light neutrino masses through the seesaw mechanism, which is also responsible for producing the observed cosmological matter-antimatter asymmetry of the universe. We find interesting correlation between the low scale neutrino observables and the baryon asymmetry in this model. Baryon number violating nucleon decay processes mediated by the scalar diquarks and leptoquarks in this framework are found to be, n, p → + m, c + m (m = meson, = lepton, c = antilepton) and n, p → + c + c . For some choice of the parameters of the theory, these decay rates can be within the observable range. Another baryon number violating process, the neutron-antineutron oscillation can also be in the observable range. *

Characters and group invariant polynomials of (super)fields: road to “Lagrangian”

“…On comparing with [68], we have found some discrepancies. We observe that the operator structure ΦΣ(Σ † ) 2 is absent in [68], whereas the Hilbert Series output contains 4 operators having this structure as well as their hermitian conjugates. We have shown the explicit forms of those operators in Table 8.…”

“…The Pati-Salam model also has a rich scalar structure to facilitate symmetry breaking. We consider the most general form of Pati-Salam [68] where scalar fields transform as (1, 1, 1), (1, 2, 2), (15, 2, 2), (10, 3, 1) and (10, 1, 3). On top of that, a global Pecci-Quinn U (1) P Q symmetry is imposed.…”

“…We also observe an under-counting w.r.t. the operator structure ΣΣ † Δ R Δ L , while [68] contains only 1 such operator (and its hermitian conjugate), Hilbert Series output contains 2 such operators (and their hermitian conjugates). Table 3 Dictionary for translation of operators from the Hilbert Series to their covariant forms.…”

“…We have suppressed the indices in the Yukawa terms. Notation for the indices is same as in[68], i.e., α, β, γ , κ = 1, 2 are SU (2) L indices, α,β,γ ,κ = 1, 2 are SU (2) R indices and μ, ν, ρ, τ, λ, ξ, ζ, ω = 1, 2, 3, 4 are SU (4) C indices…”

Stop search in SUSY SO(10) GUTs with nonuniversal Gaugino masses

“…The spinor representation in SO (10) GUTs is 16 dimensional, and all the matter fermions of a family along with a right-handed neutrino can fit into a single multiplet (16 i ). The presence of a right-handed neutrino per family helps to implement seesaw mechanism for tiny neutrino masses (see, for instance, [96][97][98][99][100][101][102][103]) as well as it can account for the baryon asymmetry of the Universe through leptogenesis (see, for instance, [104][105][106][107][108][109][110]).…”