Study On The Parameterization Of The Nucleon Boer-Mulders Function

Boer-Mulders function is a transverse momentum dependent(TMD)parton distribution function with the property of time-reversal invariance,which can effectively describe the distribution of transversely polarized quarks in unpolarized hadrons.The study of Boer-Mulders function is helpful to understand the transverse spin structure in nucleons.Based on the TMD factorization theorem,the unpolarized cos2? asymmetry of the unpolarized Drell-Yan process includes the coupling contribution of Boer-Mulders function between two initial hadrons and the contribution of perturbed quantum chromodynamics(QCD).Due to the large error in the parametric study of Boer-Mulders function in the collinear framework,the transverse momentum dependent factorization theorem considering the evolution of TMD is used to study the parameterization process of Boer-Mulders function.The comparison between the phenomenological calculation of unpolarized and transversely polarized ? n Drell-Yan process and compass experimental measurement results verifies the reliability of TMD factorization scheme and evolution effect.Then,combined with the measurement data of cos2? azimuthal asymmetry of unpolarized pp and pd Drell-Yan processes by E866/NuSea Collaboration at FNAL,taking into account the TMD factorization theorem and TMD evolution effect of transverse momentum dependent distribution function,the Boer-Mulders function of nucleon is parameterized.We can also use the universal parametric Boer-Mulders function to predict the physical observability of other related high-energy scattering processes,so as to deepen our understanding of nucleon internal spin structure and QCD.