Higgs precision measurements and flavor physics: a supersymmetric example

Abstract

[Review for "Chinese Science Bulletin" and CEPC+SPPC Proposal] Rare decays in flavor physics often suffer from Helicity suppress and Loop suppress. Helicity flip is a direct consequence of chiral $U(3)$ symmetry breaking and electroweak symmetry breaking. The identical feature is also shared by the mass generation of SM fermions. In this review, we use MSSM as an example to illustrate an explicit connection between bottom Yukawa coupling and rare decay process of $b\to s\gamma$. We take a symmetry approach to study the common symmetry breaking in supersymmetric correction to bottom quark mass generation and $b\to s\gamma$. We show that Large Peccei-Quinn symmetry breaking effect and $R$-symmetry breaking effect required by $b\to s\gamma$ inevitably lead to significant reduction of bottom Yukawa ${y}_{b}$. To compromise the reduction in $b\bar{b}$, a new decay is also needed to keep the Higgs total width as the SM value.