CP asymmetries of B to phi K_S and B to eta' K_S in SUSY GUT Model with Non-universal Sfermion Masses

TL;DR

This paper investigates CP asymmetries in B meson decays within a SUSY GUT framework with non-universal sfermion masses, showing potential deviations from the Standard Model due to gluino and chargino effects.

Contribution

It introduces a SUSY GUT model with non-universal third-generation sfermion masses, analyzing its impact on CP asymmetries in B decays and highlighting the significance of chargino contributions.

Findings

CP asymmetries can deviate by about 0.1 from SM predictions.

Constructive interference between gluino and chargino contributions influences CP asymmetries.

Light stops, gluinos, and higgsinos help relax Higgs sector fine-tuning.

Abstract

We analyze CP asymmetries of B \to \phi K_S and B \to \eta' K_S in a supersymmetric grand unified theory in which only the third generation sfermions contained in 10(Q, U^c, E^c) of SU(5) can have a different mass from the others. One of the advantages of this nonuniversal mass model is that the first two generation sfermion masses can be large whereas both (left and right handed) stops are light so as to stabilize the weak scale. Therefore, we studied a minimal supersymmetric standard model parameter region in which a fine tuning in Higgs sector is relaxed owing to light masses of stops, gluino and higgsinos. In such a parameter region, the chargino contribution is as important as the gluino one. We show that the CP asymmetries of B \to \phi K_S and B \to \eta' K_S can deviate from their standard model predicted values by O(0.1) because of constructive interference between gluino and chargino contributions.