The Study Of Top Quark And Higgs Boson Decay To Charmonium At The LHC

Heavy quarkonium physics is one of the most important research topics in high energy physics,and it provides a rich and ideal platform for understanding the perturbative and non-perturbative Quantum Chromodynamics(QCD).Nowadays,the theoretical description of the production and decay processes of heavy quarkonium——Nonrelativistic QCD(NRQCD)is still the primary choice in this field,and its experimental verification is one of the most urgent tasks in heavy quarkonium physics.Since it was proposed,NRQCD has successfully explained most experimental results of heavy quarkonium,and achieved successes in heavy quarkonium related processes that have attracted worldwide attention.Meanwhile,since running,The large hadron collider(LHC)has been the most important tool for studying the internal structure of particles,the discovery of new particles,and testing theoretical models.Therefore,LHC is an ideal place for us to study the heavy quarkonium Physics.In this paper,based on the NRQCD factorization,two jobs have been done at the LHC;The study of ?cJW+b associated production from top quark decay,and J/?(r)? associated production from Higgs boson decay.In the first work,we calculated the next-to-leading order(NLO)QCD corrections to ?cJW+b associated production from top quark decay.In this process,Although the color-octet(CO)contributions are dominant at the leading-order(LO),because the 3PJ(1)(J=0,1,2)Fock state give important negative contribution,the overall NLO results are not too big after NLO CO correction.Our results show that it is very difficult to detect the ?c0 production from top quark deacy,but the production of ?c1 and ?c2 are likely to be detected at the LHC.If the ?cJ production form top quark decay can be detected at the LHC,it's not only helpful to the study of the J/? production from top quark decay,but also has great significance to the understand the production of heavy quarkonium mechanism.In the second work,we investigated J/?(r)? associated production from Higgs boson decay.For the direct process,the decay width of H?J/?(r)+?process is significantly reduced by NLO QCD correction at the LO.In the case of the indirect process.H??*? through virtual ? decaying to J/?(Y),our calculations include all standard model(SM)Feynman diagrams.The results show that the decay width of indirect production is far greater than the direct decay width.Due to it is very clean in the experiment,H?J/?(r)+? decay process can be observed at 14 TeV LHC,and it provides a new way to probe the Yukawa coupling and New Physics at the LHC,too.The innovation of this paper lies in investigating the processes of top quark and Higgs boson decay to charmonium at the LHC,and made the NLO QCD corrections at first time.Our results indicate that,by the NLO QCD corrections,it is possible to detect the ?c1 and ?c2 production,and the Yukawa coupling of Higgs boson and bottom quark at the LHC.If these processes can be detected at the LHC in the future,which will provide important references for testing theoretical models and exploring New Physics.