论文标题
横向动量从NLL BFKL扩大到PQCD中的所有订单
Transverse momentum broadening from NLL BFKL to all orders in pQCD
论文作者
论文摘要
我们研究了所有扰动QCD的订单，饱和动量$ q_s（l）的普遍行为控制了通过大尺寸$ l $的密集QCD介质传播的快速parton的横向动量分布。由于饱和动量的量子演化的双对数性质，其大$ L $渐近肌是通过略微从近代到领先的log（NLL）BFKL或领先顺序DGLAP Evolution Evolution Evolution Equolution方程的双对数极限稍微偏离而获得的。在固定的耦合，或在共形$ \ Mathcal {n} = 4 $ sym理论中，我们将$ q_s（l）$的大$ l $扩展定为$α_s^{3/2} $。在QCD中，有无质量的夸克，在强耦合常数的运行中，保形对称性被打破了，单循环QCD $β$ - 功能充分说明了$ q_s（l）$扩展中的通用项。因此，该系列的通用系数在$α_s$中的所有订单中都完全熟悉。
We study, to all orders in perturbative QCD, the universal behavior of the saturation momentum $Q_s(L)$ controlling the transverse momentum distribution of a fast parton propagating through a dense QCD medium with large size $L$. Due to the double logarithmic nature of the quantum evolution of the saturation momentum, its large $L$ asymptotics is obtained by slightly departing from the double logarithmic limit of either next-to-leading log (NLL) BFKL or leading order DGLAP evolution equations. At fixed coupling, or in conformal $\mathcal{N}=4$ SYM theory, we derive the large $L$ expansion of $Q_s(L)$ up to order $α_s^{3/2}$. In QCD with massless quarks, where conformal symmetry is broken by the running of the strong coupling constant, the one-loop QCD $β$-function fully accounts for the universal terms in the $Q_s(L)$ expansion. Therefore, the universal coefficients of this series are known exactly to all orders in $α_s$.
