Top-quark Decays to Higgs boson in MSSM

TL;DR

This paper investigates potential enhancements of the rare top-quark decay to a Higgs boson within the MSSM framework, highlighting scenarios where new physics signals could be detectable at the LHC.

Contribution

It provides a detailed calculation of top-quark to Higgs decay rates in MSSM, identifying two scenarios with significantly increased branching ratios that could be observed experimentally.

Findings

Two enhanced decay scenarios identified involving SUSY breaking terms.

Potential for observable FCNC signals at current or future LHC runs.

Calculations consider various constraints and cancellations.

Abstract

The decay of top-quark to light quarks and Higgs boson is an extremely rare process in the Standard Model (SM) framework. Any measurable signal for this process at the LHC is a smoking gun for new physics. In the framework of Minimal Supersymmetric Standard Model (MSSM) there is a possibility that the branching ratio for this process to reach values several orders of magnitude larger than the corresponding of SM. Having as a primary goal the search of Flavour Changing Neutral Currents (FCNC) processes that could be measurable at current or future LHC runing, we present a calculation in the framework of R-parity conserving MSSM for the decay of top quark to light quarks and the Higgs boson. Considering different constraints, and carefully looking at the cancellations that occur between different contributions, we deduce that there are two possible enhanced scenarios for this process: the first arises from the holomorphic SUSY breaking terms containing right handed up squark mass insertions and the second comes from the dominance of non-holomorphic SUSY breaking terms in combination with a light Higgs boson sector.