Measurement Of Charged Jet Spectrum In Proton-proton Collisions At 13TeV In ALICE At LHC

Quantum chromo-dynamics(QCD)is the theory used to describe the strong interaction of standard model.LQCD predicts that extreme high temperature and high density conditions will leader to the exchange of particles from hadronic to QGP.In the experimental,we use the large heavy ion accelerator to produce condition for the production of quark-gluon plasma(QGP),such as the Large Hadron Collider(LHC)of European Nuclear Research Center(CERN),and the Relativistic Heavy Ion Collider(RHIC)of Bludhaven laboratory(BNL),etc.Since the QGP material will be rapidly cooling down after it have been produced,we can not observe the existence of monomer quark in the lab,so people want to use some special probes,such as jet,photon,etc,to study the properties of QGP.RHIC first observed the suppression of inclusive high pt hadron production and the modification of high pt dihadron angular correlations in nuclear-nuclear collisions.LHC is capable of reaching the collision energy of the order of TeV,witch is much larger than RHIC,so it provides detail information on the jet-quenching effect by using fully reconstructed jets,correlations between jets and singular particles,and charged particles measurements.The energy density generated by the final state of the collision of the RUN-? system is much higher than that of RUN-? by studying the multiplicity of charged particles in 13TeV p-p collision in RUN-?.The experimental data analysis of RUN-? shows that there are may be signs of QGP material production in small system collision.Therefor,the study of jet in 13TeV can not only test pQCD,but also understand the hard scattering process in the nucleus-nucleus collisions.During my master's period,I mainly use the data of LHC-ALICE 13TeV proton proton collisions to do all the analysis.First,the LHC15f data of run-? are analyzed comprehensively.It is found that the distribution of charged particles is not uniform and can not be used to do jet-physics analysis.Then LHC161 data is used,according to the following steps:charged particles analysis—jet reconstruction—modified detector effect.Finally,we can get the jet yield ratio.In this paper,we use LHC161 data,through the quality analysis of tracks,so that get some runs which is better for physics analysis,and get original spectrum for different jet size.Then the Monte Carlo simulation data of 13TeV provide by LHC-ALICE are used to correct the detector effect The corrected method is mainly based on the singular value decomposition,and Bayesian method is used to do cross check.Finally we get the yield ratio of jet,and confirming that the reconstruction of high transverse momentum jet does not depend on the size of R.