Implications of a high mass light MSSM Higgs scalar for SUSY searches at the LHC

TL;DR

This paper explores the implications of a high-mass light MSSM Higgs scalar for SUSY searches at the LHC, analyzing parameter spaces that produce Higgs masses above 130 GeV and their detectability.

Contribution

It identifies specific SUSY parameter regions that yield a high-mass Higgs and discusses their potential signatures and challenges for LHC detection.

Findings

High m0 (~10-20 TeV) and A0 (~±2m0) favor a Higgs mass >130 GeV.

Low m1/2 (<1 TeV) allows gluino production and decay signatures at LHC.

High m1/2 spectra likely out of LHC reach, with dark matter implications.

Abstract

The Atlas and CMS collaborations have both reported an excess of events in the WW\star \rightarrow \ell+\ell- + ETmiss search channel, which could be the first evidence for the Higgs boson. In the context of the MSSM, the lightest SUSY Higgs scalar h is expected to occur with mass mh = 135 GeV, depending on the range of SUSY parameters scanned over. Since the h \rightarrow WW\star branching fraction falls swiftly with decreasing mh, a signal in the WW\star channel would favor an h at the high end of its predicted mass range. We scan over general GUT scale SUSY model parameters to find those which give rise to mh > 130 GeV. A value of m0 \sim 10 - 20 TeV is favored, with A0 \sim \pm2m0, while the lower range of m1/2 < 1 TeV is also slightly favored. This gives rise to an "effective SUSY" type of sparticle mass spectrum. For low m1/2, gluino pair production followed by three-body gluino decay to top quarks may ultimately be accesible to LHC searches, while for higher m1/2 values, the SUSY spectra would likely be out of range of any conceivable LHC reach. Since the thermal neutralino relic abundance tends to be very high, late-time entropy dilution or neutralino decay to light axinos would be required to gain accord with the measured dark matter abundance