Triplet leptogenesis, type-II seesaw dominance, intrinsic dark matter, vacuum stability and proton decay in minimal SO(10) breakings

Abstract

We implement type-II seesaw dominance for neutrino mass and baryogenesis through heavy scalar triplet leptogenesis in a class of minimal non-supersymmetric SO(10) models where matter parity as stabilising discrete symmetry as well as WIMP dark matter (DM) candidates are intrinsic predictions of the GUT symmetry. We also find modifications of relevant CP-asymmetry formulas in such minimal models. Baryon asymmetry of the universe as solutions of Boltzmann equations is further shown to be realized for both normal and inverted mass orderings in concordance with cosmological bound and best fit values of the neutrino oscillation data including θ 23 in the second octant and large values of leptonic Dirac CP-phases. Type-II seesaw dominance is at first successfully implemented in two cases of spontaneous SO(10) breakings through SU(5) route where the presence of only one non-standard Higgs scalar of intermediate mass ∼ 10 9 − 10 10 GeV achieves unification. Lower values of the SU(5) unification scales ∼ 10 15 GeV are predicted to bring proton lifetimes to the accessible ranges of Super-Kamiokande and Hyper-Kamiokande experiments. Our prediction of WIMP DM relic density in each model is due to a ∼ TeV mass matter-parity odd real scalar singlet (⊂ 16 H ⊂ SO(10)) verifiable by LUX and XENON1T experiments. This DM is also noted to resolve the vacuum stability issue of the standard scalar potential. When applied to the unification framework of M. Frigerio and T. Hambye, in addition to the minimal fermionic triplet DM solution of 2.7 TeV mass, this procedure of type-II seesaw dominance and triplet leptogenesis is also found to make an alternative prediction of triplet fermion plus real scalar singlet DM at the TeV scale. * *

Neutrino masses, vacuum stability and quantum gravity prediction for the mass of the top quark

“…At first glance and only focusing on the sign of the contribution to the flow of the Higgs quartic coupling, the answer to the latter is most likely positive. Indeed, the presence of an extra scalar, the SU(2) triplet, gives a positive contribution to the β-function of the Higgs quartic coupling and stabilises the vacuum if the triplet mass is close to or below the SM critical scale [11,12,20,[102][103][104][105]. However, the question becomes non-trivial when we add the input from asymptotic safety.…”

“…Despite being inaccessible at particle colliders, a JHEP01(2021)180 high scale seesaw has very interesting applications in particle physics and cosmology. For instance, it could account for the baryon asymmetry of the universe through leptogenesis [10][11][12] (for a review see refs. [13,14]), constitute a dark matter candidate [15][16][17][18] and play a role for inflation [19][20][21] or dark energy [22].…”

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]).…”

Threshold effects in SO(10) models with one intermediate breaking scale

“…Threshold corrections [30,31] are loop level corrections arising from fields lying at and around the scale of symmetry breaking that modify the matching conditions of the gauge couplings of the models above and below the energy scale of symmetry breaking. This can in turn modify the value of M GUT and thereby save some of the models that were previously disfavored [27,[32][33][34][35][36][37][38][39]. Furthermore, since threshold corrections modify the matching conditions of the gauge couplings, they can allow for unification in models where the gauge couplings do not unify [40][41][42].…”