首页 | 本学科首页   官方微博 | 高级检索  
     检索      


Antiproton-nucleus electromagnetic annihilation as a way to access the proton timelike form factors
Authors:H Fonvieille and V A Karmanov
Institution:1.Laboratoire de Physique Corpusculaire,Université Blaise Pascal, IN2P3,Aubière Cedex,France;2.Lebedev Physical Institute,Moscow,Russia
Abstract:Contrary to the reaction \( \bar{{p}}\) p \( \rightarrow\) e + e - with a high-momentum incident antiproton on a free target proton at rest, in which the invariant mass M of the e + e - pair is necessarily much larger than the \( \bar{{p}}\) p mass 2m , in the reaction \( \bar{{p}}\) d \( \rightarrow\) e + e - n the value of M can take values near or below the \( \bar{{p}}\) p mass. In the antiproton-deuteron electromagnetic annihilation, this allows to access the proton electromagnetic form factors in the timelike region of q2 near the \( \bar{{p}}\) p threshold. We estimate the cross-section \(d\sigma _{\bar pd \to e^ + e^ - n} /d\mathcal{M}\) for an antiproton beam momentum of 1.5GeV/c. We find that near the \( \bar{{p}}\) p threshold this cross-section is about 1pb/MeV. The case of heavy-nuclei target is also discussed. Elements of experimental feasibility are presented for the process \( \bar{{p}}\) d \( \rightarrow\) e + e - n in the context of the \( \overline{{{\rm P}}}\) ANDA project.
Keywords:
本文献已被 SpringerLink 等数据库收录!
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号