Search for Z' Resonances Decaying to Tau Pairs in pp Collisions Using CMS Detector at the LHC

摘要

103.1 Introduction The Standard Model (SM) of particle physics has been explored successfully by various experimental observations at the LHC. But still, it is not the complete theory of nature. Many models have been proposed to explain physics beyond the SM which predict the existence of new heavy gauge bosons W' and Z' by including an additional U(l) group to the SM gauge group [1]. The universality of couplings is not necessary for these new gauge bosons. There exist models that incorporate generation-dependent couplings which results in Z' bosons preferentially decaying to the third generational fermions. Such models motivate a search for Z' resonances that decay to a pair of r leptons such as topcolor-assisted technicolor (TAT) models [2-4]. A widely used benchmark model in searches for Z' bosons is the sequential standard model (SSM), which predicts a neutral spin-1 Z' boson (Z'_(SSM)) with the same couplings to quarks and leptons as that of the SM Z boson. Z'_(SSM) decaying to a pair of electrons and muons have been excluded below 3.4 [5] and 3.2 [6] TeV respectively while the exclusion limit is 2.0 TeV in tau lepton pair final state [7-9]. In this paper, searches for Z' resonance decaying to tau pairs in SSM and TAT models have been presented on a data sample of pp collisions corresponding to an integrated luminosity of 2.2 fb~(-1) at {formula}= 13 TeV recorded with the CMS detector [10] at the LHC.