"Extra Figure g8ct[Z65]" of "Study of quark and gluon jet substructure in Z+jet and dijet events from pp collisions"

Measurements of jet substructure describing the composition of quark- and gluon-initiated jets are presented. Proton-proton (pp) collision data at sqrt(s)=13 TeV collected with the CMS detector are used, corresponding to an integrated luminosity of 35.9/fb. Generalized angularities are measured that characterize the jet substructure and distinguish quark- and gluon-initiated jets. These observables are sensitive to the distributions of transverse momenta and angular distances within a jet. The analysis is performed using a data sample of dijet events enriched in gluon-initiated jets, and, for the first time, a Z+jet event sample enriched in quark-initiated jets. The observables are measured in bins of jet transverse momentum, and as a function of the jet radius parameter. Each measurement is repeated applying a "soft drop" grooming procedure that removes soft and large angle radiation from the jet.For easier navigation, figures are named with a code with each letter/number representing in the following order: ungroomed/groomed, AK4/AK8, charged, multiplicity/pTD2/thrust/width/LHA, [central dijet/forward dijet/Z+jet, PT].

本研究展示了针对夸克引发喷注（quark-initiated jets）与胶子引发喷注（gluon-initiated jets）的组成特性开展的喷注子结构（jet substructure）测量结果。本次分析使用了CMS探测器（CMS detector）采集的质心系能量√s=13 TeV的质子-质子（pp）碰撞数据，对应的积分亮度（integrated luminosity）为35.9 fb⁻¹。我们测量了广义角距（generalized angularities）可观测量，该类可观测量可用于刻画喷注子结构特征，并区分夸克引发喷注与胶子引发喷注。上述可观测量对喷注内部的横向动量（transverse momentum）分布与角间距（angular distances）分布具有敏感性。分析过程分别使用了富含胶子引发喷注的双喷注事件（dijet events）样本，以及首次采用的富含夸克引发喷注的Z+jet事件样本。上述可观测量按照喷注横向动量的分箱开展测量，并以喷注半径参数（jet radius parameter）为函数进行表征。所有测量均重复应用了「软滴（soft drop）」喷注修整流程，该流程可移除喷注内的软辐射与大角度辐射。为便于查阅，所有图表均采用编码命名，各字母/数字依次代表以下类别：未修整（ungroomed）/已修整（groomed）、AK4/AK8、带电粒子（charged）、多重数（multiplicity）/pTD2/推力（thrust）/喷注宽度（width）/LHA、[中心区双喷注（central dijet）/前向区双喷注（forward dijet）/Z+jet、PT]。