Photoproduction Of The J/?-pair At The LHC With Forward Detector Acceptances

Since the J/? was first discovered experimentally in 1974,the study of quarkonium production and decay mechanism has become an important topic in particle physics.The heavy quarkonium is a multiple scale system,whose decay and production are relate to several energy regimes of Quantum Chromodynamics(QCD).On the production and annihilation mechanism of heavy quarkonium,physicists have proposed several models,such as color singlet model,color evaporation model and NRQCD.All these models divide the production of quarkonium into two steps,that is,describing the perturbed part of quark pair production and the process of quarkonization.In all of these models,Non-releativistic QCD(NRQCD)is a widely accepted theory.In NRQCD theoretical framework,the idea of perturbative factorization is inherited from Colour-Singlet Model(CSM),the production or decay of heavy quarkonium is separated into two parts:short distance part and the long distance part.The short distance part mainly involves the production of heavy quark pairs,and the long distance part involves the hadronization of heavy quark pairs into heavy quarkonium.And the long distance matrix elements(LDMEs),which can be extracted from experimental data.Recently,NRQCD theory has become a basic tool for calculating the heavy quarkonium decay and production.There is a very important reaction process in high energy physics,pp?p+X+p,that is Central Exclusive Production.The colliding proton radiation produces the intermediate state X,and the two outgoing protons remain intact.In order to study this process,FP420 partners plan to install silicon and fast timing detector,namely to pre proton detector,on ATLAS and CMS on LHC.By installing these detectors,the LHC can provide many new collision modes such as the ?p and ??,the background of these collision process is very clean,which is helpful for us to study the standard model and new physics.The first chapter of this paper introduces LHC and related detectors,FP420 detector and photon-induced process.The second chapter introduces the standard model,the third chapter introduces the color singlet model,color evaporation model and non-relativistic QCD on the mechanism production.In the fourth chapter,we study the photon-induced production of double J/? on the LHC,calculate the cross sections of all states,and analyze the signal and background of the process of double J/? decay to the pure muon.