Unification for Yukawas and its implications

TL;DR

This paper explores how large soft A-terms in supersymmetric SU(5) GUT models can unify Yukawa couplings for lighter generations without extra Higgs multiplets, affecting sfermion spectra and flavor-changing processes.

Contribution

It demonstrates that large soft A-terms enable Yukawa unification for lighter generations within minimal SU(5) without additional Higgs multiplets, and analyzes resulting sfermion spectrum distortions and flavor implications.

Findings

Large A-terms achieve Yukawa unification for light generations.

Sfermions can be lighter than 1 TeV with unification.

Flavor-changing processes are significantly affected.

Abstract

The supersymmetric finite threshold effects are studied in the presence of non minimal soft terms that can correct the problematic mass ratios of the light generations in the minimal SU(5) GUT. We show that with large soft A-terms, one can achieve simple unification for lighter generations without additional Higgs multiplet, while having sfermions lighter than 1 TeV. The presence of such large A-terms will distort the sfermion mass spectrum upon running from GUT scale down to the electroweak scale making it distinct from the universal SUSY breaking scenarios, especially in the first two generations. The implications of these splittings are studied in K and D meson oscillations and in rare processes D^+ -> pi^+ nu anti-nu and K^+ -> pi^+ nu anti-nu, and in the latter case the effect is found to be important.