H(SUSY)->tau+tau->hadron+hadron channel, its advantages and potential instrumental drawbacks

TL;DR

This study explores the high-mass tau+tau- decay channel in CMS, highlighting its advantages for mass reach and resolution, while discussing potential instrumental challenges and background reduction strategies.

Contribution

It provides the first detailed analysis of the H/A -> tau+tau- channel at high masses in CMS, emphasizing its superior mass reach and potential for early detection.

Findings

High-mass reach in m(A) tan(beta) space demonstrated

Tau+tau- channel offers best mass resolution among studied channels

Background reduction via Etmiss cuts significantly improves signal detection

Abstract

We present a first study of the channel H, A -> tau+tau -> h+ + h- + X in CMS at high m(A) values where no triggering difficulties are expected with QCD jets. At present the tau selection is based solely on the presence of a hard isolated track in the "tau" jet, but further refinements based on calorimeter collimation or impact parameter selections are obviously possible. The main irreducible background in these conditions is due to QCD jets with hard fragmentations. A large reduction of this background and improvement in the expected signal to background ratio is provided by Etmiss cuts. The expected high-mass reach in the m(A) tan(beta) parameter space for 3 x 10**4pb**-1 is shown. This H -> tau+tau channel provides the highest mass reach and the best mass resolution when compared to tau,tau -> lepton+hadron + Xand tau,tau -> electton + muon + X final states. To the extent that with further calorimetric and impact parameter based selection criteria the QCD background can be kept under control, i.e. below the irreducible Z,gamma* -> tau+tau background, we should strive to have a first level trigger allowing to explore the mass range down to ~ 150 - 200 GeV.