Contributions from SUSY-FCNC couplings to the interpretation of the HyperCP events for the decay \Sigma^+ \to p \mu^+ \mu^-

TL;DR

This paper explores how the NMSSM's light pseudoscalar Higgs boson can explain the HyperCP events involving the decay of Sigma+ to proton and muons, fitting experimental data without conflicting with existing constraints.

Contribution

It identifies specific regions in the SUSY-FCNC parameter space where the NMSSM's A1_0 can account for HyperCP events, expanding understanding of potential new physics explanations.

Findings

NMSSM's A1_0 can explain HyperCP events within certain parameter regions.

The model remains consistent with kaon decay and mixing constraints.

The proposed explanation does not contradict existing experimental bounds.

Abstract

The observation of three events for the decay $\Sigma^+ \to p \mu^+ \mu^-$ with a dimuon invariant mass of $214.3\pm0.5$MeV by the HyperCP collaboration imply that a new particle X may be needed to explain the observed dimuon invariant mass distribution. We show that there are regions in the SUSY-FCNC parameter space where the $A^0_1$ in the NMSSM can be used to explain the HyperCP events without contradicting all the existing constraints from the measurements of the kaon decays, and the constraints from the $K^0-\bar{K}^0$ mixing are automatically satisfied once the constraints from kaon decays are satisfied.