The Study Of Mono-Top Signature From Stop Decay At The HE-LHC

"God particle"-the discovery of the Higgs particle,making 2012 a milestone year in particle physics.Because it announced that the last piece of the standard model puzzle that the particle physics community has been searching for for nearly half a century has finally been completed.This is exciting.But at the same time,”dark clouds in the sky" followed.Although the Standard Model has achieved great success,it also has limitations and cannot answer a series of questions such as the hierarchy problem,asymmetry of positive and negative matter,cosmic inflation,neutrino mass and so on.Therefore,just as the scope of application of special relativity and general relativity is different,the standard model is also regarded as a low-energy effective model.For higher-energy situations,physicists generally believe that there are new physics,and they have also proposed a variety of new models,such as the Grand Unified Theory,Super Symmetry Theory(SUSY),Super String Theory,and Membrane Theory,etc.Among the new models proposed in this series,the supersymmetry theory has attracted much attention due to its unique symmetry beauty.Supersymmetry introduces a kind of symmetry between fermions and bosons,that is,each boson corresponds to a fermion and The reverse is also worked.In this way,the problem of the standard model can be solved naturally,that is,the catastrophic problem of the square divergence of the Higgs mass under the single-loop correction is naturally offset by the loop graph contribution of the introduced supersymmetric partner.The supersymmetry theory predicts a series of particles to solve the hierarchy problem.Among them,the stop particle,the super partner of the top particle,plays a pivotal role.There is an inseparable relationship between finding light stop particles and testing the naturalness of supersymmetry theory.In fact,many people have already started this work before.On the Large Hadron Collider(LHC)of the European Organization for Nuclear Research(CERN),stop particles are mainly produced through strong interactions,and it has a better effective cross section for the generation process and therefore theoretically more easy to observe.This paper mainly discusses the single stop production process of weak interaction.Although the result is not better than the stop pair production,it can still be used as a supplementary test plan for the stop production process,because it can also understand the electroweak properties of stop particles.We use the Monte Carlo simulation method to simulate the collision of single stop production process on the real collider,and assume an extremely simple model that the supersymmetric particles produced are only stop and chargino.In addition,we also set some other parameters so that the generated stop particles are right-handed and are of the Higgs partner class of the electroweak partner class,such as setting tan ?=50 mU3R<<mQ3L and ?<<M1,2.Then through data analysis,the following conclusions are obtained:·At the 27 TeV LHC with the integrated luminosity of L=15 ab-1,mt1<1900 GeV and ?<750 GeV can be excluded at 2? through the leptonic mono-top channel.·Compared with the electroweak process generated by the leptonic channel without quantum chromodynamics(QCD)background,the result of hadronic channel is relatively worse because the Z+jets background under the standard model is too large.mt1<1200 GeV and ?<350 GeV can be excluded at 2? through the hadronic channel.