Implications of the Higgs Discovery in the MSSM Golden Region

TL;DR

This paper explores how combined measurements of the Higgs mass and event rate at the LHC can help determine stop sector parameters in the MSSM, especially in the light stop and large mixing 'golden' region.

Contribution

It demonstrates that Higgs decay measurements can be used to extract stop mass matrix parameters, highlighting the importance of the pseudoscalar mass m_A and the potential to estimate mixing without knowing mma.

Findings

m_A is crucial for extracting stop parameters

Stop mixing can be estimated independently of mma

Combined measurements improve parameter determination in the MSSM golden region

Abstract

If the lightest CP-even Higgs boson in the MSSM is discovered at the LHC, two measurements could be made simultaneously: the Higgs mass m_h and the event rate Bs(gg -> h -> gamma gamma). We study to what extent the combination of these two measurements would allow us to extract parameters in the stop mass matrix, including the off-diagonal mixing term, with a focus on the MSSM golden region where the stops are light and the mixing is large. Even though both the production cross-section and the decay amplitude are not sensitive to supersymmetric parameters outside of the stop sector, the branching ratio depends on the total decay width, which is dominated by the Higgs decay to b quarks and sensitive to both the pseudo-scalar mass m_A and the supersymmetric Higgs mass \mu. In the end we find m_A is an important input in extracting the stop mass parameters, while a fair estimate of the off-diagonal mixing term could be obtained without prior knowledge of \mu.