Supersymmetry Unification Predictions for M_top V_cb and tan(beta)

TL;DR

This paper investigates how different supersymmetric models predict top quark mass, tan(beta), and V_cb, revealing that certain unification conditions restrict or allow large tan(beta) solutions.

Contribution

It compares MSSM and MSSM-BRpV models in fermion mass unification, showing how relaxing GUT relations affects the allowed parameter space.

Findings

Large tan(beta) solutions are disallowed in MSSM with strict GUT relations.

Allowing GUT relation deviations enables large tan(beta) in MSSM.

MSSM-BRpV permits unification across all tan(beta) values.

Abstract

We study the predictions for M_top, tan(beta) and V_cb in a popular texture ansatze for the fermion mass matrices. We do this both for the Minimal Supersymmetric Standard Model (MSSM) and for the simplest model (MSSM-BRpV) where a bilinear R-Parity violating term is added to the superpotential. We find that taking the experimental values for M_top and V_cb at 99 % C.L. and the GUT relations h_b=h_tau and (V_cb)^2=h_c/h_t within 5 %, the large tan(beta) solution, characteristic in the MSSM with bottom--tau unification, becomes disallowed. In contrast the corresponding allowed region for the MSSM-BRpV is slightly larger. We also find that important modifications occur if we relax the texture conditions at the GUT scale. For example, if the GUT relations are imposed at 40 %, the large tan(beta) branch in the MSSM becomes fully allowed. In addition, in MSSM-BRpV the whole tan(beta)-M_top plane become allowed, finding unification at any value of tan(beta).