Submitted to Phys. Rev. C Polarization Phenomena in Small-Angle Photoproduction of e e Gamm.pdf

下载文档

3
0
约3.64万字
约 22页
2017-04-06 发布于江苏
举报
版权申诉
保障服务

Submitted to Phys. Rev. C Polarization Phenomena in Small-Angle Photoproduction of e e Gamm.pdf

1、本文档共22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)。

Submitted to Phys. Rev. C Polarization Phenomena in Small-Angle Photoproduction of e e Gamm

MKPH-T-97-16FTUV/97-41; IFIC/97-41Submitted to Phys. Rev. CPolarization Phenomena in Small-Angle Photoproduction ofe+e Pairs and the Gerasimov{Drell{Hearn Sum RuleA.I. LvovP.N. Lebedev Physical Institute, Moscow, 117924, RussiaS. ScopettaDepartment of Physics, University of Perugia, I-06100 Perugia, ItalyInstitut fur Kernphysik, Universitat Mainz, D-55099 Mainz, GermanyD. Drechsel and S. SchererInstitut fur Kernphysik, Universitat Mainz, D-55099 Mainz, Germany(July 1997)AbstractPhotoproduction of e+e pairs at small angles is investigated as a tool todetermine the functions f1 and f2 entering the real-photon forward Comptonscattering amplitude. The method is based on an interference of the Bethe{Heitler and the virtual Compton scattering mechanisms, generating an az-imuthal asymmetry in the e+ versus e yield. The general case of a circularlypolarized beam and a longitudinally polarized target allows one to determineboth the real and imaginary parts of f1 as well as f2. The imaginary part off2 requires target polarization only. We calculate cross sections and asymme-tries of the reaction p( ; e+e)p, estimate corrections and backgrounds, andpropose suitable kinematical regions to perform the experiment. Our inves-tigation shows that photoproduction of e+e-pairs o the proton and lightnuclei may serve as a rather sensitive test of the validity of the Gerasimov{Drell{Hearn sum rule.13.60.Fz, 13.88.+e Typeset using REVTEXPresent address: Departament de Fisica Teorica, Universitat de Valencia, 46100 Burjassot(Valencia), Spain 1 I. INTRODUCTIONIn studies of spin-dependent structure functions of nucleons and nuclei with real andvirtual photons, the verication of the Gerasimov{Drell{Hearn sum rule (GDH) [1,2] isof special interest [3,4]. Apart from general principles as gauge and Lorentz invariance,unitarity, analyticity, and crossing symmetry, this sum rule is based on the assumption thatthe forward Compton scattering becomes spin independent at high energies.