The Forward-Backward Top Asymmetry in a Singlet extension of the MSSM

TL;DR

This paper explores how singlet extensions of the MSSM can explain the observed large forward-backward asymmetry in top-antitop quark production, aligning with experimental data and other constraints.

Contribution

It introduces non-renormalizable couplings in singlet-extended MSSM to account for the asymmetry, analyzing different singlet mass regimes for consistency with observations.

Findings

Large asymmetry achievable in small singlet mass regime

Model consistent with ttbar cross section limits

Compatible with flavor physics and top decay constraints

Abstract

The CDF and D0 collaborations have recently reported a large forward-backward asymmetry in the ttbar system which deviates from the next to-leading order QCD standard model prediction. We study the asymmetry in the ttbar system within the framework of singlet extensions of the Minimal Supersymmetric Standard Model. For this purpose, we introduce non-renormalizable couplings between first and third generation of quarks to scalars. We analyze two limiting cases of the model, characterized by the size of the supersymmetric mass for the singlet superfield. We study both the small and large limits of this mass parameter. We find that in the region of small singlet supersymmetric mass we can obtain a large asymmetry while being consistent with limits on the ttbar production cross section. These results are also consistent with constraints arising from flavor physics, quark masses and top quark decays.