Searching for H --> tau tau in weak boson fusion at the LHC

Abstract

Weak boson fusion is a copious source of intermediate mass Higgs bosons at the LHC. The additional very energetic forward jets in these events provide for powerful background suppression tools. We analyze the $H \to \tau\tau$ decay mode for the Standard Model Higgs boson. A parton level analysis of the dominant physics backgrounds (mainly $Z \to \tau\tau$ and Drell-Yan production of $\tau$'s) and of reducible backgrounds (from $W+$ jet and $b\bar{b}$ production in association with two jets and subsequent leptonic decays) demonstrates that this channel allows the observation of $H \to \tau\tau$ in a low background environment, yielding a significant Higgs signal with an integrated luminosity of about 30 fb$^{-1}$. The weak boson fusion process thus allows direct measurement of the $H\tau\tau$ coupling.