The New Minimal Supersymmetric GUT : Spectra, RG analysis and Fermion Fits

TL;DR

This paper develops a minimal supersymmetric SO(10) GUT model, deriving formulae for fermion masses and mixings, fitting experimental data, and analyzing the resulting spectra and baryon violation rates.

Contribution

It provides a comprehensive framework for fermion mass fitting, spectrum prediction, and B violation analysis within a minimal supersymmetric GUT based on SO(10).

Findings

Fits are compatible with electroweak symmetry breaking and unification.

Predicted right-handed neutrino masses range from 10^8 to 10^13 GeV.

B violation rates are much faster than current experimental limits.

Abstract

The supersymmetric SO(10) GUT based on the ${\bf{210\oplus 10\oplus 120\oplus 126\oplus {\bar {126}}}}$ Higgs system provides a minimal framework for the emergence of the R-parity exact MSSM at low energies and a viable supersymmetric seesaw explanation for the observed neutrino masses and mixing angles. We present formulae for MSSM decomposition of the superpotential invariants, tree level light charged fermion effective Yukawa couplings, Weinberg neutrino mass generation operator, and the $d=5,\Delta B=\Delta L \neq 0$ effective superpotential in terms of GUT parameters. We use them to determine fits of the 18 available fermion mass-mixing data in terms of the superpotential parameters of the NMSGUT and SUGRY(NUHM) type soft supersymmetry breaking parameters ($\{m_{\tilde f},m_{1/2},A_0,M^2_{H,\bar H}\} $) specified at the MSSM one loop unification scale $M_X^0=10^{16.33} $ GeV. Our fits are compatible with electroweak symmetry breaking and Unification constraints and yield right-handed neutrino masses in the leptogenesis relevant range : $10^8-10^{13} $ GeV. Matching the SM data requires lowering the strange and down quark Yukawas in the MSSM via large $\tan\beta$ driven threshold corrections and characteristic soft Susy breaking spectra. The Susy spectra have light pure Bino LSP, heavy exotic Higgs(inos) and large $ \mu,A_0,M_{H,\bar{H}}$ parameters $\sim 100$ TeV. Typically third generation sfermions are much \emph{heavier} than the first two generations. The smuon is often the lightest charged sfermion thus offering a Bino-CDM co-annihilation channel. The parameter sets obtained are used to calculate B violation rates which are found to be generically much faster($\sim 10^{-28}\, yr^{-1}$) than the current experimental limits. Improvements which may allow acceptable B violation rates are identified.