论文标题
$ t \ bar {t} $ events the lhc的$ b $ quark碎片对$ b $ quark碎片敏感的测量值
Measurements of jet observables sensitive to $b$-quark fragmentation in $t\bar{t}$ events at the LHC with the ATLAS detector
论文作者
论文摘要
使用36 fb $ {}^{ - 1} $ $ \ sqrt s = 13 $ \ sqrt s = 13 $ tev proton-proton碰撞数据，使用36 fb $ {}^{ - 1} $测量了对$ b $ quarks在$ b $ hadrons中的碎片敏感的几种观察力。含有$ b $ - hadrons的喷气机是从dialeptonic $ t \ bar {t} $事件的样本中获得的，相关的带电粒子轨道集分为主要$ pp $互动顶点和来自流离失所的$ b $ b $ -b $ -decay sependaryverx的轨道。该划分用于构建可观察到的，以表征$ b $ - hadron在喷气机中的纵向和横向动量分布。测量值已得到校正，以实现检测器的效应，并在LHC的系统中提供了重夸克碎片建模的测试，在该系统中，顶级衰减产物与质子束残余物有色连接。将展开的分布与几个现代Monte Carlo Parton-Shower发电机和发电机的预测进行了比较，并且观察到与数据的广泛一致，$ p $ - 价值从$ 5 \ times 10^{ - 4} $到0.98不等。这些测量值补充了$ e^+e^ - $ collider实验的类似测量结果，其中$ b $ quarks源自颜色单$ z/γ^*$。
Several observables sensitive to the fragmentation of $b$-quarks into $b$-hadrons are measured using 36 fb${}^{-1}$ of $\sqrt s = 13$ TeV proton-proton collision data collected with the ATLAS detector at the LHC. Jets containing $b$-hadrons are obtained from a sample of dileptonic $t\bar{t}$ events, and the associated set of charged-particle tracks is separated into those from the primary $pp$ interaction vertex and those from the displaced $b$-decay secondary vertex. This division is used to construct observables that characterize the longitudinal and transverse momentum distributions of the $b$-hadron within the jet. The measurements have been corrected for detector effects and provide a test of heavy-quark-fragmentation modeling at the LHC in a system where the top-quark decay products are color-connected to the proton beam remnants. The unfolded distributions are compared with the predictions of several modern Monte Carlo parton-shower generators and generator tunes, and a wide range of agreement with the data is observed, with $p$-values varying from $5 \times 10^{-4}$ to 0.98. These measurements complement similar measurements from $e^+e^-$ collider experiments in which the $b$-quarks originate from a color-singlet $Z/γ^*$.
