论文标题
重新访问LHC的$ j/ψ$对的生产
Revisiting the production of $J/ψ$ pairs at the LHC
论文作者
论文摘要
我们考虑$ k_t $ -factorization QCD方法的$ pp $碰撞中的提示双$ j/ψ$生产。使用碎裂机制，我们考虑了由ciafaloni-catani-fiorani-marchesini进化方程驱动的初始状态中多个gluon辐射的组合效应，评估了对生产横截面的颜色八位列的贡献。我们证明了这些贡献在CMS和ATLAS测量涵盖的某个运动区域的重要性。另一方面，LHCB合作在正向速度和中等横向动量的实验数据可以通过$ {\ cal o}（α_s^4）$ color Singlet项和双方散射机制的贡献很好地描述。有效横截面的提取值$σ_{\ rm eff} = 17.5 \ pm 4.1 $ 〜mb与基于不同最终状态的许多其他估计兼容。
We consider the prompt double $J/ψ$ production in $pp$ collisions at the LHC in the framework of $k_T$-factorization QCD approach. Using the fragmentation mechanism, we evaluate the color octet contributions to the production cross sections taking into account the combinatorial effects of multiple gluon radiation in the initial state driven by the Ciafaloni-Catani-Fiorani-Marchesini evolution equation. We demonstrate the importance of these contributions in a certain kinematical region covered by the CMS and ATLAS measurements. On the other hand, the experimental data taken by the LHCb Collaboration at forward rapidities and moderate transverse momenta can be described well by ${\cal O}(α_s^4)$ color singlet terms and contributions from the double parton scattering mechanism. The extracted value of the effective cross section $σ_{\rm eff} = 17.5 \pm 4.1$~mb is compatible with many other estimations based on different final states.
