Supersymmetry unification predictions for mtop, Vcb and tanβ Original Research Article

We study the predictions for mtop, tanβ and Vcb in a popular texture ansatz 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 mtop and Vcb at 99% c.l. and the GUT relations hb=hτ and Vcb2=hc/ht within 5%, the large tanβ 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 tanβ branch in the MSSM becomes fully allowed. In addition, in MSSM–BRpV the whole tanβ–mtop plane become allowed, finding unification at any value of tanβ.