Lepton Flavour Violating Heavy Higgs Decays Within the nuMSSM and Their Detection at the LHC

TL;DR

This paper explores the potential to detect lepton flavour violating heavy Higgs decays within the nuMSSM at the LHC, highlighting enhanced decay rates and production mechanisms at large eta, and assesses the discovery prospects for various Higgs masses.

Contribution

It demonstrates that heavy Higgs decays into  pairs can be significantly enhanced in the nuMSSM at large , providing new detection channels at the LHC.

Findings

Higgs to  branching ratios can reach 10^{-4} at large .

Detection of  signals is feasible up to 600 GeV Higgs mass with 300 fb^{-1}.

Even with 10 fb^{-1}, Higgs masses up to 400 GeV can be probed at =60.

Abstract

Within the $\nu$MSSM, a Minimal Supersymmetric neutrino See-saw Model, Lepton Flavour Violating Higgs couplings are strongly enhanced at large $\tan\beta$ ($\gsim30$), which can lead to BR$(H^0/A^0 \to \tau\mu) \simeq O(10^{-4})$, for $M_{H^0/A^0}\gsim 160$ GeV. Enhancements on the production of Higgs bosons, through the gluon fusion mechanism, $gg\to H^0/A^0$, and the associated production channel $gg,q\bar q\to b\bar bH^0/A^0$, whose rates grow with $\tan\beta$, as well as the mass degeneracy that occurs between the $H^0$ and $A^0$ states in this regime, also contribute to further the possibilities to detect a heavy Higgs signal into $\tau\mu$ pairs. We show that the separation of $\tau\mu$ Higgs events from the background at the upcoming CERN Large Hadron Collider could be done for Higgs masses up to about 600 GeV for 300 fb$^{-1}$ of luminosity, for large $\tan\beta$ values. However, even with as little as 10 fb$^{-1}$ one can probe $H^0/A^0$ masses up to 400 GeV or so, if $\tan\beta=60$. Altogether, these processes then provide a new Higgs discovery mode as well as an independent test of flavour physics.