Supersymmetric parameter constraints from isospin asymmetry in b -> s gamma transitions

TL;DR

This paper uses isospin asymmetry in b -> s gamma decays to impose strict constraints on supersymmetric models, especially within the MSSM framework considering various SUSY-breaking scenarios.

Contribution

It provides a detailed analysis of isospin asymmetry as a new observable to constrain supersymmetric parameters in different SUSY-breaking models.

Findings

Isospin asymmetry imposes strong restrictions on MSSM parameters.

Most SUSY-breaking scenarios are highly constrained by the observable.

NLO contributions are crucial for accurate constraints.

Abstract

Isospin asymmetry in b -> s gamma transitions provides severe constraints on new physics parameters, due to the small values of the experimental measurements. We exploit here this new observable to study different supersymmetric models. For this purpose, we calculate the isospin symmetry breaking in the MSSM with minimal flavor violation, considering NLO contributions. We study three scenarios for supersymmetry breaking, namely mSUGRA, AMSB and GMSB. In most of the explored regions, we find very restrictive constraints on the allowed parameters for these models.