The recent measurement of the differential γ ＋ c-jet cross section, performed at the Tevatron collider in Run II by the D0 collaboration, is studied in a next-to-leading order（NLO） global QCD analysis to assess it...The recent measurement of the differential γ ＋ c-jet cross section, performed at the Tevatron collider in Run II by the D0 collaboration, is studied in a next-to-leading order（NLO） global QCD analysis to assess its impact on the proton parton distribution functions（PDFs）. We show that these data lead to a significant change in the gluon and charm quark distributions. We demonstrate also that there is an inconsistency between the new high precision HERA I＋II combined data and Tevatron measurement. Moreover, in this study we investigate the impact of older EMC measurements of charm structure function F_c^2 on the PDFs and compare the results with those from the analysis of Tevatron data. We show that both of them have the same impact on the PDFs, and thus can be recognized as the same evidence for the inefficiency of perturbative QCD in dealing with charm production in some kinematic regions.展开更多
Having a precise knowledge of the charm quark component can lead to a better understanding of the fundamental structure of the nucleon. Furthermore, the charm quark distribution function plays an important role in the...Having a precise knowledge of the charm quark component can lead to a better understanding of the fundamental structure of the nucleon. Furthermore, the charm quark distribution function plays an important role in the study of many processes which are sensitive to the charm quark content of the nucleon. In the standard global analysis of patton distribution functions （PDFs）, the charm quark distribution arises perturbatively through the splitting of the gluon into charm-anticharm pairs in the DGLAP evolution equations. Nevertheless, the existence of nonperturbative intrinsic charm quarks in the proton has also been predicted by QCD. In this paper, we study some phenomenological models within the light-cone framework to predict the nonperturbative intrinsic charm quark content of the nucleon. We investigate the impact of these models on the prediction ofγ-＋ c-jet production in pp collisions at the LHC and compare our results on pp→γ, ＋ c-jet with the experimental data of DO.展开更多
文摘The recent measurement of the differential γ ＋ c-jet cross section, performed at the Tevatron collider in Run II by the D0 collaboration, is studied in a next-to-leading order（NLO） global QCD analysis to assess its impact on the proton parton distribution functions（PDFs）. We show that these data lead to a significant change in the gluon and charm quark distributions. We demonstrate also that there is an inconsistency between the new high precision HERA I＋II combined data and Tevatron measurement. Moreover, in this study we investigate the impact of older EMC measurements of charm structure function F_c^2 on the PDFs and compare the results with those from the analysis of Tevatron data. We show that both of them have the same impact on the PDFs, and thus can be recognized as the same evidence for the inefficiency of perturbative QCD in dealing with charm production in some kinematic regions.
文摘Having a precise knowledge of the charm quark component can lead to a better understanding of the fundamental structure of the nucleon. Furthermore, the charm quark distribution function plays an important role in the study of many processes which are sensitive to the charm quark content of the nucleon. In the standard global analysis of patton distribution functions （PDFs）, the charm quark distribution arises perturbatively through the splitting of the gluon into charm-anticharm pairs in the DGLAP evolution equations. Nevertheless, the existence of nonperturbative intrinsic charm quarks in the proton has also been predicted by QCD. In this paper, we study some phenomenological models within the light-cone framework to predict the nonperturbative intrinsic charm quark content of the nucleon. We investigate the impact of these models on the prediction ofγ-＋ c-jet production in pp collisions at the LHC and compare our results on pp→γ, ＋ c-jet with the experimental data of DO.
