SUSY and Higgs Signatures Implied by Cancellations in $b\to s\gamma$

TL;DR

This paper explores how cancellations in supersymmetric contributions to the $b o s\gamma$ decay suggest the existence of light charged Higgs and sparticles, with potential early detection at the LHC, especially in large $ aneta$ scenarios.

Contribution

It reveals that cancellations between charged Higgs and chargino contributions imply light supersymmetric particles and highlights Higgs signatures as primary discovery channels in certain parameter regions.

Findings

Large cancellations between charged Higgs and chargino contributions occur.

Light sparticles are implied by the constraints and cancellations.

Higgs signatures may dominate over sparticle signatures in some scenarios.

Abstract

Recent re-evaluations of the Standard Model (SM) contribution to ${\mathcal Br(b\to s\gamma)$ hint at a positive correction from new physics. Since a charged Higgs boson exchange always gives a positive contribution to this branching ratio, the constraint points to the possibility of a relatively light charged Higgs. It is found that under the HFAG constraints and with re-evaluated SM results large cancellations between the charged Higgs and the chargino contributions in supersymmetric models occur. Such cancellations then correlate the charged Higgs and the chargino masses often implying both are light. Inclusion of the more recent evaluation of $g_{\mu}-2$ is also considered. The combined constraints imply the existence of several light sparticles. Signatures arising from these light sparticles are investigated and the analysis indicates the possibility of their early discovery at the LHC in a significant part of the parameter space. We also show that for certain restricted regions of the parameter space, such as for very large $\tan\beta$ under the $1\sigma$ HFAG constraints, the signatures from Higgs production supersede those from sparticle production and may become the primary signatures for the discovery of supersymmetry.