arXivDaily arXiv每日学术速递 周一至周五更新
arXiv 1602.01989hep-ph
收藏

$pA$碰撞中CGC湮灭过程中的光子

Photon from the annihilation process with CGC in the $pA$ collision

Sanjin Benic, Kenji Fukushima

摘要:

本文在色玻璃凝聚体(CGC)的框架下,讨论了质子色源$ρ_p$在$pA$碰撞中的光子产生.我们工作在这样一个区域:原子核的色密度$ρ_A$足够大,可以证明CGC处理的合理性,而质子中的软胶子可能比夸克成分占优势,但还不属于CGC区域,因此我们仍然可以将振幅扩展到$ρ_p$的幂。已知对光子产生的零阶贡献来自韧致辐射过程,一阶修正包括产生对的夸克的韧致辐射图和涉及胶子的夸克湮灭图,来源于$ρ_p$。因为最终状态不同,所以这两个过程之间没有干扰。在这项工作中,我们阐明了详细的计算程序只专注于湮灭图。使用McLerran-Venugopalan模型的颜色平均值,我们数值计算的光子产生率,并讨论适合的数值结果的函数形式。

英文摘要:

We discuss the photon production in the $pA$ collision in a framework of the color glass condensate (CGC) with expansion in terms of the proton color source $ρ_p$. We work in a regime where the color density $ρ_A$ of the nucleus is large enough to justify the CGC treatment, while soft gluons in the proton could be dominant over quark components but do not yet belong to the CGC regime, so that we can still expand the amplitude in powers of $ρ_p$. The zeroth-order contribution to the photon production is known to appear from the Bremsstrahlung process and the first-order corrections consist of the Bremsstrahlung diagrams with pair produced quarks and the annihilation diagrams of quarks involving a gluon sourced by $ρ_p$. Because the final states are different there is no interference between these two processes. In this work we elucidate calculation procedures in details focusing on the annihilation diagrams only. Using the McLerran-Venugopalan model for the color average we numerically calculate the photon production rate and discuss functional forms that fit the numerical results.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

↑