Heavy leptons fromWdecay

Abstract

We investigate the possibility of detecting a new heavy lepton at the $\overline{p}p$ collider through the decay mode $W\ensuremath{\rightarrow}L{\ensuremath{\nu}}_{L}$. We consider both the leptonic ($L\ensuremath{\rightarrow}e{\ensuremath{\nu}}_{e}{\overline{\ensuremath{\nu}}}_{L}$) and hadronic ($L\ensuremath{\rightarrow}\overline{q}Q{\overline{\ensuremath{\nu}}}_{L}$) sequential decays of the $L$. We present detailed calculations to show that the leptonic decay rate is exceeded, for all kinematic ranges, by background contributions from $W\ensuremath{\rightarrow}e{\ensuremath{\nu}}_{e}$ and $W\ensuremath{\rightarrow}\ensuremath{\tau}{\ensuremath{\nu}}_{\ensuremath{\tau}}\ensuremath{\rightarrow}e{\ensuremath{\nu}}_{e}{\overline{\ensuremath{\nu}}}_{\ensuremath{\tau}}{\ensuremath{\nu}}_{\ensuremath{\tau}}$ decays. On the other hand, the hadronic decay leads to a promising, distinctive signature: a large missing transverse momentum balanced by two recognizable jets. Selective cuts can be imposed to remove background contributions, and the remaining event rate is about 10% of the $W\ensuremath{\rightarrow}e\ensuremath{\nu}$ rate if the mass of the lepton is below 50 GeV.