Small Angle Polarization in High Energy P--P Scattering Through Nonperturbative Chiral Symm.pdf

下载文档

2
0
约1.95万字
约 13页
2017-04-06 发布于江苏
举报
版权申诉
保障服务

Small Angle Polarization in High Energy P--P Scattering Through Nonperturbative Chiral Symm.pdf

1、本文档共13页，可阅读全部内容。
2、有哪些信誉好的足球投注网站（book118）网站文档一经付费（服务费），不意味着购买了该文档的版权，仅供个人/单位学习、研究之用，不得用于商业用途，未经授权，严禁复制、发行、汇编、翻译或者网络传播等，侵权必究。
3、本站所有内容均由合作方或网友上传，本站不对文档的完整性、权威性及其观点立场正确性做任何保证或承诺！文档内容仅供研究参考，付费前请自行鉴别。如您付费，意味着您自己接受本站规则且自行承担风险，本站不退款、不进行额外附加服务；查看《如何避免下载的几个坑》。如果您已付费下载过本站文档，您可以点击这里二次下载。
4、如文档侵犯商业秘密、侵犯著作权、侵犯人身权等，请点击“版权申诉”（推荐），也可以打举报电话：400-050-0827(电话支持时间：9:00-18:30)。

Small Angle Polarization in High Energy P--P Scattering Through Nonperturbative Chiral Symm

a r X i v : h e p - p h / 9 2 1 1 2 2 1 v 1 6 N o v 1 9 9 2 DFTT 62/92 October 1992 SMALL ANGLE POLARIZATION IN HIGH ENERGY P–P SCATTERING THROUGH NONPERTURBATIVE CHIRAL SYMMETRY BREAKING Mauro Anselminoa,b and Stefano Forteb Dipartimento di Fisica Teorica, Universita? di Torinoa and I.N.F.N., Sezione di Torinob via P. Giuria 1, I-10125 Torino, Italy ABSTRACT We show that a large anomalous contribution due to nonperturbative instanton-like gluonic field configurations to the axial charge of the proton implies high-energy spin effects in p? p elastic scattering. This is the same mechanism which is responsible for anomalous baryon number violation at high energy in the standard model. We compute the proton polarization due to these effects and we show that it is propor- tional to the center-of-mass scattering angle with a universal (energy-independent) slope of order unity. Submitted to: Physical Review Letters 0 There are many indications, both experimental and theoretical,(1) that perturbative techniques may be insufficient to account for spin effects, even at high energy. It has been suggested (2,3) that the so-called “proton spin” problem(4) may be such an instance. Namely, the observed smallness of the axial charge of the proton may be due to a cancella- tion between the axial charge of quarks, which are expected to carry most of the proton’s helicity, and a chirality-violating contribution triggered by the axial anomaly through the nonperturbative gluon configurations required to solve the U(1) problem.(5?7) This implies that, even at high energy, chiral symmetry can be violated in the strong interactions, and entails the possibility of unusual polarization effects. It is the purpose of this paper to describe one such effect. We shall compute the effec- tive pseudoscalar (helicity-flipping) nucleon-nucleon-n gluon interaction which is induced by the coupling of the nucleon to instanton vacuum configurations, analogously to what is done in treatments of bary