The Study Of Z’ Bosons Effects In The Processes Of Ppâ†'eÏ„/μτ+X At The LHC

In the past few decades, the standard model(SM) of particle physics is consistent with almost all theexperimental facts,. However, there are so many components put by hand on its theoretical frameworkthat the SM can not act as an ultimate theory for the strong, weak and electromagnetic interaction,and,there are also many problems(both theoritical and experimental) in the SM. Peoplenaturally expect there will exist new physics at a higher energy scale, such as TeV scale (10^16GeV), and in this sense, the SM is only a low energy effective theory. The shortcoming of the SM is thebasic motivation for people to explore new physics beyond the SM.There could naturely be an extra broken U (1) gauge symmetry corresponding to a massive gaugebosons arises from many extended models for the SM, such as models based on the string theoryor the grand unified theory(GUT), models with a dynamically interpretation for the gaugesymmetry breaking and models with supersymmety, and so on. In these models, the massive,electrically neutral, spin-1and color-singlet particle(commonly denoted as Z’) has been widelyphenomenological studied: on one hand, direct searches have been doing at high-energycolliders, on the other hand, lots of theoritical works, such as to give limitations on the masssand couplings to specific particles by using the data at low energy scale. Generally, in the Z’models, the couplings of Z’ with the SM fermions could be generation-nonuniversal, and could alsobe generation-universal as an special case. Due to many interesting phenomenological significance,the generation-nonuniversal couplings is more attractive for the researchers in recent years.Signals with leptons as final state has very clean background at the hadron colliders, so itcould be quite sensitive to detect effects of the new physics and be able to detect the effectsthrough these signals. There have been many researches on the charged lepton signals at the hadroncolliders, with the same flavor for the paired leptons, but due to the limitations on theaccumulation of experimental examples and the capability for detection and analytisis, lack studieson signals with the same flavor for the paired leptons have been done. According to SM, thelepton number and baryon number is strictly conserved, and flavor changing neutral currents(FCNC) attree level are forbidden(the GIM mechanism). But the FCNC is allowed to appear at tree levelin the generation-non-universal Z’ models. With the run of the Large Hadron Collider(LHC) andthe large accumulation of experimental datum, it will be able to improve the understanding of newphysical effects of Z’. We have calculated cross section for the ppâ†'eÏ„/the μτ+Xprocess at LHC, the results show that it may be observable to detect the signals of the Z’ boson if the couplings of Z’ to the SM fermions is not too small. We then give the comparisonwith the numerous phenomenological models. Our results could be used to give discriminationand identification on new physics models(such as, by the global fitting), and to givemore studies one specific new physical effects of Z ’boson.