Pion electromagnetic form factor in the k(T) factorization formulae
文献类型：期刊论文
| 作者 | Wu XG(吴兴刚); 黄涛(理) ; Wu, XG; Huang, T
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| 刊名 | INTERNATIONAL JOURNAL OF MODERN PHYSICS A
 |
| 出版日期 | 2006 |
| 卷号 | 21期号:4页码:901-904 |
| 关键词 | higher helicity components twist-3 k(T) dependence |
| 通讯作者 | Chinese Acad Sci, Inst High Energy Phys, Beijing 100049, Peoples R China |
| 英文摘要 | Based on the light-cone (LC) framework and the k(T) factorization formalism, the transverse momentum effects and the different helicity components' contributions to the pion form factor F-pi(Q(2)) are recalculated. In particular, the contribution to the pion form factor from the higher helicity components (lambda(1) + lambda(2) = +/- 1), which come from the spin-space Wigner rotation, are analyzed in the soft and hard energy regions respectively. Our results show that the right power behavior of the hard contribution from the higher helicity components can only be obtained by fully keeping the kT dependence in the hard amplitude, and that the kT dependence in LC wavefunction affects the hard and soft contributions substantially. A model for the twist-3 wavefunction psi(p)(x, k (perpendicular to)) of the pion has been constructed based on the moment calculation by applying the QCD sum rules, whose distribution amplitude has a better end-point behavior than that of the asymptotic one. With this model wavefunction, the twist-3 contributions including both the usual helicity components (lambda(1) + lambda(2) = 0) and the higher helicity components (lambda(1) + lambda(2) = +/- 1) to the pion form factor have been studied within the modified pQCD approach. Our results show that the twist-3 contribution drops fast and it becomes less than the twist-2 contribution at Q(2) similar to 10GeV(2). The higher helicity components in the twist-3 wavefunction will give an extra suppression to the pion form factor. When all the power contributions, which include higher order in alpha(S), higher helicities, higher twists in DA and etc., have been taken into account, it is expected that the hard contributions will fit the present experimental data well at the energy region where pQCD is applicable. |
| 学科主题 | Physics |
| 类目[WOS] | Physics, Nuclear ; Physics, Particles & Fields |
| 研究领域[WOS] | Physics |
| 原文出处 | SCI |
| 语种 | 英语 |
| WOS记录号 | WOS:000236392600049 |
| 源URL | [http://ir.ihep.ac.cn/handle/311005/238703]  |
| 专题 | 高能物理研究所_理论物理室 |
| 作者单位 | 中国科学院高能物理研究所 |
| 推荐引用方式 GB/T 7714 | Wu XG,Huang T,Wu, XG,et al. Pion electromagnetic form factor in the k(T) factorization formulae[J]. INTERNATIONAL JOURNAL OF MODERN PHYSICS A,2006,21(4):901-904. |
| APA | 吴兴刚,黄涛,Wu, XG,&Huang, T.(2006).Pion electromagnetic form factor in the k(T) factorization formulae.INTERNATIONAL JOURNAL OF MODERN PHYSICS A,21(4),901-904. |
| MLA | 吴兴刚,et al."Pion electromagnetic form factor in the k(T) factorization formulae".INTERNATIONAL JOURNAL OF MODERN PHYSICS A 21.4(2006):901-904. |
入库方式： OAI收割
来源：高能物理研究所
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