Transverse momentum balance and angular distribution of ■dijets in Pb + Pb collisions

【摘要】 In this study,the production of inclusive b-jet and bb dijets in Pb+Pb collisions has been investigated by considering the in-medium evolution of heavy and light quarks simultaneously.The initial hard processes of inclusive b-jet and bb dijets production are described using a next-to-leading order （NLO） plus parton shower Monte Carlo（MC） event generator,SHERPA,which can be well matched with the experimental data in p+p collisions.The framework uses the Langevin transport model to describe the evolution of the bottom quark.Furthermore,the collisional energy loss and higher-twist description are considered to determine the radiative energy loss from both the bottom and light quarks.We compare the theoretical simulation of the inclusive jet and b-jetR_AAin the Pb+Pb collisions at (S_NN)^1/2=2.76 TeV ith the experimental data and present the theoretical simulation of the momentum balance of the bb dijet in the Pb+Pb collisions at5.02Te V along with recent CMS data for the first time.A similar trend to that seen in inclusive dijets is observed in bb dijets;the distribution of the production shifts to smaller x_J owing to the jet quenching effect.Finally,we report the prediction of the normalized azimuthal angle distribution of the bb dijet in the Pb+Pb collisions at5.02Te V.The medium-induced energy loss effect of the bb dijets will generally suppress its production;however,the same side （??→0region） suffers more energy loss than the far side （??→πregion）,thus leading to suppression on the same side and enhancement on the far side in the normalized azimuthal angle distribution in A+A collisions.collisions.更多还原

【Abstract】 In this study,the production of inclusive b-jet and bb dijets in Pb+Pb collisions has been investigated by considering the in-medium evolution of heavy and light quarks simultaneously.The initial hard processes of inclusive b-jet and bb dijets production are described using a next-to-leading order （NLO） plus parton shower Monte Carlo（MC） event generator,SHERPA,which can be well matched with the experimental data in p+p collisions.The framework uses the Langevin transport model to describe the evolution of the bottom quark.Furthermore,the collisional energy loss and higher-twist description are considered to determine the radiative energy loss from both the bottom and light quarks.We compare the theoretical simulation of the inclusive jet and b-jetR_AAin the Pb+Pb collisions at (S_NN)^1/2=2.76 TeV ith the experimental data and present the theoretical simulation of the momentum balance of the bb dijet in the Pb+Pb collisions at5.02Te V along with recent CMS data for the first time.A similar trend to that seen in inclusive dijets is observed in bb dijets;the distribution of the production shifts to smaller x_J owing to the jet quenching effect.Finally,we report the prediction of the normalized azimuthal angle distribution of the bb dijet in the Pb+Pb collisions at5.02Te V.The medium-induced energy loss effect of the bb dijets will generally suppress its production;however,the same side （??→0region） suffers more energy loss than the far side （??→πregion）,thus leading to suppression on the same side and enhancement on the far side in the normalized azimuthal angle distribution in A+A collisions.collisions.更多还原