Peccei-Quinn symmetry and nucleon decay in renormalizable SUSY SO(10)

Abstract

We suggest simple ways of implementing Peccei-Quinn (PQ) symmetry to solve the strong CP problem in renormalizable SUSY SO(10) models with a minimal Yukawa sector. Realistic fermion mass generation requires that a second pair of Higgs doublets survive down to the PQ scale. We show how unification of gauge couplings can be achieved in this context. Higgsino mediated proton decay rate is strongly suppressed by a factor of (M PQ /M GUT ) 2 , which enables all SUSY particles to have masses of order TeV. With TeV scale SUSY spectrum, p → νK + decay rate is expected to be in the observable range. Lepton flavor violating processes µ → eγ decay and µ − e conversion in nuclei, induced by the Dirac neutrino Yukawa couplings, are found to be within reach of forthcoming experiments. *

Flavor Hierarchies from Clockwork in SO(10) GUT

“…Since these parameters are all interrelated in SO (10) and since they should fit different hierarchical patterns in the charged fermion and the neutral fermion sectors, finding an acceptable fit is a highly non-trivial task. This issue has been been extensively studied in the literature and the consistency of the minimal Yukawa sector established [12][13][14][15][16][17][18][19][20][21][22][23][24][25][26][27][28][29]. In particular, the reactor neutrino mixing angle θ 13 was predicted to be large and close to its experimentally measured value.…”

“…To fit the fermion masses and mixings, we perform a χ 2 analysis, for which we closely follow the procedure discussed in detail in Refs. [27,28]. From Eq.…”

“…Furthermore, we take the GUT scale values of the charged fermion masses and CKM mixing parameters from Ref. [28]. In this procedure, the Yukawa couplings, the CKM parameters, and the d = 5 effective operator for neutrino masses and mixings are run from the M Z scale to the SUSY scale, which is chosen to be 1 TeV.…”

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

“…2 For fits to fermion masses and mixings within the SO(10) framework see for example Refs. [21][22][23][24][25][26][27][28][29][30][31][32][33][34][35].…”

Pati-Salam axion

“…The scenario above is both simple and elegant enough for it to be taken seriously. Given the fact that it was clearly envisioned around four decades ago by Mohapatra and Senjanović [23] in the context of SO (10), and often reconsidered in different ways and at different levels of depth [24][25][26][27][28][29][30][31][32][33][34][35][36][37][38][39][40][41][42], it is worth to spend few words on why again now and why the Pati-Salam axion.…”