论文标题
在Parton分支方法中，低质量Drell-Yan生产的低质量DREL-YAN产生的横向动量频谱
The transverse momentum spectrum of low mass Drell-Yan production at next-to-leading order in the parton branching method
论文作者
论文摘要
在文献中已经观察到，低质量的drell-yan（Dy）横向动量光谱在低质量中心能量$ \ sqrt {s} $的扰动QCD计算中并未很好地描述该区域的近线性分解中，该区域中横向动量与Dy Dy量相当的区域中。我们从Parton分支（PB）方法的角度检查了此问题，将硬过程的近代到领先顺序（NLO）计算与横向动量依赖（TMD）Parton分布的演变相结合。我们将我们的预测与低DY质量的实验测量进行了比较，并找到很好的一致性。此外，我们使用低$ \ sqrt {s} $的低质量DY测量值来确定PB-TMDS固有高斯分布的宽度$ q_s $。我们发现与早期在PB -TMD应用到大型强子对撞机（LHC）和HERA的高能过程中使用的值接近。我们发现，即使在$ p_t/m_ {dy} \ sim 1 $的区域中，在低质量和低$ \ sqrt {s} $中，多种软gluon排放的贡献（包括在PB-TMDS中）对于描述它们是必不可少的，而在较大的质量中，$ m_ {dy} = sim colties and of sim c} $。 $ p_t/m_ {dy} \ sim 1 $的区域很小。
It has been observed in the literature that measurements of low-mass Drell-Yan (DY) transverse momentum spectra at low center-of-mass energies $\sqrt{s}$ are not well described by perturbative QCD calculations in collinear factorization in the region where transverse momenta are comparable with the DY mass. We examine this issue from the standpoint of the Parton Branching (PB) method, combining next-to-leading-order (NLO) calculations of the hard process with the evolution of transverse momentum dependent (TMD) parton distributions. We compare our predictions with experimental measurements at low DY mass, and find very good agreement.In addition we use the low mass DY measurements at low $\sqrt{s}$ to determine the width $q_s$ of the intrinsic Gauss distribution of the PB-TMDs at low evolution scales. We find values close to what has earlier been used in applications of PB -TMDs to high-energy processes at the Large Hadron Collider (LHC) and HERA. We find that at low DY mass and low $\sqrt{s}$ even in the region of $p_t/m_{DY} \sim 1$ the contribution of multiple soft gluon emissions (included in the PB-TMDs) is essential to describe themeasurements, while at larger masses ($m_{DY} \sim m_{Z}$) and LHC energies the contribution from soft gluons in the region of $p_t/m_{DY}\sim 1$ is small.
