Using Tau Polarization for Charged Higgs Boson and SUSY Searches at LHC

Understand

The $\tau$ polarization can be easily measured at LHC in the 1-prong hadronic $\tau$ decay channel by measuring what fraction of the $\tau$-jet momentum is carried by the charged track.

• A simple cut requiring this fraction to be >0.8 retains most of the polarization of $\tau=$+1 $\tau$-jet signal while suppressing the polarization of $\tau=$-1 $\tau$-jet background and practically eliminating the fake $\tau$ background.
• This can be utilized to extract the charged Higgs signal.
• It can be also utilized to extract the SUSY signal in the stau NLSP region, and in particular the stau co-annihilaton region.