华东师范大学学报（自然科学版） >

2015 , Vol. 2015 >Issue 1: 195 - 202

DOI: https://doi.org/10.3969/j.issn.1000-5641.2015.01.024

应用物理

核子中部分子分布函数的研究

  • 徐仕磊 ,
  • 阮建红
展开
  • 华东师范大学 物理系, 上海 200241
第一作者:徐仕磊, 男,硕士研究生, 研究方向为粒子物理. E-mail: shileixu1989@gmail.com

收稿日期: 2014-04-01

  网络出版日期: 2015-03-29

基金资助

国家自然科学基金(10875044)

收起

Research on parton distributions in nucleon

  • XU Shi-Lei ,
  • RUAN Jian-Hong
Expand
  • Department of Physics, East China Normal University, Shanghai 200241, China

Received date: 2014-04-01

  Online published: 2015-03-29

Fold

摘要

通过对几个著名小组GJR,MSTW和CTEQ的领头阶部分子分布函数进行仔细分析和比较,包括分析在不同动量标度下它们的价夸克、海夸克和胶子的分布函数以及各种部分子所占有的质子总动量,发现在小x区域,不同研究小组的胶子和海夸克的分布函数差别非常明显,说明人们对它们的认识还远未清晰.通过计算分析高扭度效应对部分子分布函数的影响,发现遮蔽效应使小x和中x区域的扭度-4的胶子和海夸克的分布函数略小于扭度-2的分布函数,反遮蔽效应使x≥2区域的扭度-4的胶子和海夸克分布函数大于相应的扭度-2的分布函数.最后, 从数值计算角度验证了MD-DGLAP演化方程是符合动量守恒定律的

关键词： 部分子分布函数; 高扭度效应; 演化方程

本文引用格式

徐仕磊 , 阮建红 . 核子中部分子分布函数的研究[J]. 华东师范大学学报（自然科学版）, 2015 , 2015(1) : 195 -202 . DOI: 10.3969/j.issn.1000-5641.2015.01.024

Abstract

We present the parton distributions at leading order (LO) coming from GJR, MSTW and CTEQ parton sets and compare them at different momentum scales. Obvious differences exist in their gluon and sea quark distributions at small x region. Itindicates that people have not known the nucleon parton distributions very well. We analysze the influence of higher twist effects, i.e., the shadowing effects and anti-shadowing effects, on parton distributions. Because of the shadowing effects, the twist-4 gluon and sea quark distributions are smaller than the twist-2 distributions at small and middle x region, while, the anti-shadowing effects make the twist-4 gluon and sea quark distributions larger than the twist-2 distributions at x & 2 region. Finally, we present a detailed analysis of how the proton’s momentum is shared among various parton flavors at different Q2 for different parton sets. With the numerical calculation, we show that the MD-DGLAP equations are momentum conservation.

Key words： parton distributions; higher twist effect; evolution equation

参考文献

MARTIN A D, STIRLING W J, THORNE R S, et al. Parton distributions for the LHC [J]. European Physical Journal C, 2009 (63): 189-285.
PUMPLIN J, STUMP D R, HUSTON J, et al. New generation of parton distributions with uncertainties from global QCD analysis [J]. Journal of High Energy Physics, 2002, 07(012): 1-47.
GLUCK M, JIMENEZ-DELGADO P, REYA E. Dynamical parton distributions of the nucleon and very small-x physics [J]. European Physical Journal C, 2008(53): 355-366.
GRIBOV L V, LEVIN E M, RYSKIN M G. Semihard processes in QCD [J]. Physics Reports, 1983(100): 1-150.
MULLER A H, QIU J W. Gluon recombination and shadowing at small values of x [J]. Nuclear Physics B, 1986(268): 427-452.
ZHU W. A new approach to parton recombination in the evolution equations [J]. Nuclear Physics B, 1999(551): 245-274.
ZHU W, RUAN J H. A new modified Altarelli-Parisi evolution equation with parton recombination in proton [J]. Nuclear Physics B, 1999(559): 378-392.
RUAN J H, ZHU W. Prediction for unintegrated parton distributions [J]. Physical Review C, 2009, 80(045209): 1-13.
杨东岩, 阮建红. 扭度-4效应对核子极化结构函数的影响~[J]. 华东师范大学学报: 自然科学版, 2009, 01:128-136
ZHU W, RUAN J H, YANG J F, et al. Contributions of gluon recombination to saturation phenomena [J]. Physical Review D, 2003, 68(094015): 1-11.
Options
文章导航

/

〈 〉