Theory for quarkonium:from NRQCD factorization to soft gluon factorization  

作　　者：An-Ping Chen Yan-Qing Ma 陈安平;马滟青(School of Physics and State Key Laboratory of Nuclear Physics and Technology,Peking University,Beijing 100871,China;Center for High Energy physics,Peking University,Beijing 100871,China;College of Physics and Communication Electronics,Jiangxi Normal University,Nanchang 330022,China;Collaborative Innovation Center of Quantum Matter.Beijing 100871,China)

机构地区：[1]School of Physics and State Key Laboratory of Nuclear Physics and Technology,Peking University,Beijing 100871,China [2]Center tor High Energy physics,Peking University,Beijing 100871,China [3]College of Physics and Communication Electronics,Jiangxi Normal University,Nanchang 330022,China [4]Collaborative Innovation Center of Quantum Matter.Beijing 100871,China

出　　处：《Chinese Physics C》2021年第1期196-207,共12页中国物理C（英文版）

基　　金：Supported by the National Natural Science Foundation of China(11875071,11975029);the China Postdoctoral Science Foundation(2018M631234)。

摘　　要：We demonstrate that the recently proposed soft gluon factorization(SGF)is equivalent to the nonrelativistic QCD(NRQCD)factorization for heavy quarkonium production or decay,which means that,for any given process,these two factorization theories are either both valid or both violated.We use two methods to arrive at this conclusion.In the first method,we apply the two factorization theories to the physical process J/ψ→e^+e^-.Our explicit calculation shows that both SGF and NRQCD can correctly reproduce the low energy physics of full QCD,and the two factorizations are thus equivalent.In the second method,by using equations of motion,we successfully deduce SGF from NRQCD effective field theory.By identifying SGF with NRQCD factorization,we establish relations between the two factorization theories and prove the generalized Gremm-Kapustin relation as a byproduct.Compared with the NRQCD factorization,the advantage of SGF is that it resums the series of relativistic corrections originating from kinematic effects to all powers,yielding better convergence of the relativistic expansion.

关 键 词：FACTORIZATION QUARKONIUM nonrelativistic QCD soft gluon 

分 类 号：O572.243[理学—粒子物理与原子核物理]