论文标题
$ j/ψ$ plus $ w $/$ z $生产在LHC上的限制对非顾问QCD QCD长距离矩阵元素
Constraints on Nonrelativistic-QCD Long-Distance Matrix Elements from $J/ψ$ Plus $W$/$Z$ Production at the LHC
论文作者
论文摘要
我们研究了在非层次QCD（NRQCD）的分解方法中，以$α_s$为$α_S$的临时QCD（NRQCD）在分解方法中研究及时的$ j/ψ$中的相关产生，或者通过Intermedied Midediate color color singlet $ {^3} s_1^s_1^{[1]} $ and $ {[1] $ and $ {^3} $ {^1S} _0^{[8]} $，$ {^3S} _1^{[8]} $和$ {^3p} _J^{[8]} $状态。要求我们的预测与最近的ATLAS测量值兼容，这对Charmonium长距离矩阵元素（LDMES）的新约束严格构成是非扰动的，无扰动的，无关的输入参数。考虑到安装在单个$ j/ψ$包容性生产数据的四个流行的LDME集合中，我们发现其中一个与数据略微兼容，中心预测通常会降低三倍，一个不足，短缺的因素是一个数量级，大约是一个数量方案，而直接$ j/ψ+w/z $ w/z $ w/z $ w/z $ w/z $。 Atlas观察到的迅速$ j/ψ$ Plus $ W $生产的较高速度为NRQCD分解固有的颜色八位格机制提供了有力的证据，而领先的颜色单元贡献仅以$ \ MATHCAL {o}（g_fα_s^4）$输入，超出了此处考虑的订单。
We study the associated production of prompt $J/ψ$ mesons and $W$ or $Z$ bosons within the factorization approach of nonrelativistic QCD (NRQCD) at next-to-leading order in $α_s$, via intermediate color singlet ${^3}S_1^{[1]}$ and ${^3}P_J^{[1]}$ and color octet ${^1S}_0^{[8]}$, ${^3S}_1^{[8]}$ and ${^3P}_J^{[8]}$ states. Requiring for our predictions to be compatible with recent ATLAS measurements yields stringent new constraints on charmonium long-distance matrix elements (LDMEs) being nonperturbative, process-independent input parameters. Considering four popular LDME sets fitted to data of single $J/ψ$ inclusive production, we find that one is marginally compatible with the data, with central predictions typically falling short by a factor of three, one is unfavored, the factor of shortfall being about one order of magnitude, and two violate cross section positivity for direct $J/ψ+W/Z$ production. The large rate of prompt $J/ψ$ plus $W$ production observed by ATLAS provides strong evidence for the color octet mechanism inherent to NRQCD factorization, the leading color singlet contribution entering only at $\mathcal{O}(G_Fα_s^4)$, beyond the order considered here.
