色玻璃凝聚中Sudakov效应对矢量介子产生的影响  

Sudakov Effect on Vector Meson Production in the Framework of Color Glass Condensate

作　　者：向文昌 蔡燕兵 周代翠[2] XIANG Wenchang;CAI Yanbing;ZHOU Daicui(Key Laboratory of Econophysics,Guizhou University of Finance and Economics,Guiyang 550025,Guizhou,China;Institute of Particle Physics,Central China Normal University,Wuhan 430079,Hubei,China)

机构地区：[1]贵州财经大学金融物理重点实验室,贵州贵阳550025 [2]华中师范大学粒子物理研究所,湖北武汉430079

出　　处：《武汉大学学报（理学版）》2022年第3期236-244,共9页Journal of Wuhan University:Natural Science Edition

基　　金：国家自然科学基金(11765005)。

摘　　要：在色玻璃凝聚框架下,将Sudakov效应运用到矢量介子产生中,计算了衍射遍举和衍射离解两种过程中轻(φ)和重(J/ψ)介子产生的微分截面和总截面。首先,利用数值方法求解微分积分形式的领头阶偶极子演化方程和Sudakov抑制的次领头阶偶极子演化方程,得到相应的偶极子散射振幅,研究发现Sudakov抑制的次领头阶偶极子散射振幅小于同一快度下领头阶的偶极子散射振幅,随着快度增加两者之间的差距越来越大,由此表明Sudakov效应压低了偶极子散射振幅的演化速度。其次,将这些偶极子散射振幅应用到衍射矢量介子产生模型中,描述HERA(hadron electron ring accelerator)能区φ和J/ψ介子产生相关实验数据,得到Sudakov抑制时的χ^(2)/N_(p)=1.26远小于领头阶时的χ^(2)/N_(p)=1.87,由此Sudakov效应提高了模型的精度,使得修正后的偶极子散射振幅能较好地描述相关数据,表明了Sudakov效应在矢量介子产生中起着重要的作用。In the framework of color glass condensate,the Sudakov effect is applied to study vector meson production.The differential cross sections and total cross sections of light(φ)and heavy(J/ψ)mesons productions in diffractive exclusive process and diffractive dissociative process are calculated.Firstly,the leading order and next-to-leading order Sudakov suppressed dipole scattering amplitudes are obtained by numerically solving the integro-differential dipole evolution equations.We found that the next-to-leading order Sudakov suppressed dipole scattering amplitudes are smaller than the leading ones for a same rapidity,and the gap between these two amplitudes becomes larger and larger with the rapidity increasing,which indicates that the Sudakov effect suppresses the evolution speed of the dipole amplitude.Secondly,these numerical solutions are used in the diffractive vector meson production model to describe the φ and J/ψexperimental data at HERA(hadron electron ring accelerator)energies.The correspondingχ^(2)/N_(p)=1.26 for Sudakov case is much smaller thanχ^(2)/N_(p)=1.87 for leading order case,which shows that the Sudakov effect improves the precision of vector meson production model.The Sudakov modified dipole scattering amplitudes give a better description of the experimental data,which indicates that the Sudakov effect plays an important role in vector meson production.

关 键 词：胶子饱和物理 矢量介子产生 衍射过程 

分 类 号：O572.3[理学—粒子物理与原子核物理]