"Table 21" of "Study of Hadronic Event-Shape Variables in Multijet Final States in pp Collisions at $\sqrt{s}$ = 7 TeV"
收藏资源简介:
CERN-LHC. Event-shape variables, which are sensitive to perturbative and nonperturbative aspects of quantum chromodynamic (QCD) interactions, are studied in multijet events recorded in proton-proton collisions at $\sqrt{s}=7$ TeV. Events are selected with at least one jet with transverse momentum $p_T > 110$ GeV and pseudorapidity $\mid\eta\mid < 2.4$, in a data sample corresponding to integrated luminosities of up to $5 fb^{-1}$. The distributions of five event-shape variables in various leading jet $p_T$ ranges are compared to predictions from different QCD Monte Carlo event generators. Five event-shape variables are analyzed in this paper: the transverse thrust $\tau_{\perp}$, the total jet broadening $B_{tot}$, the total jet mass $\rho_{tot}$, the total transverse jet mass $\rho^T_{tot}$ and the third-jet resolution parameter $Y_{23}$. In the formulae below, $p_{T,i}$, $\eta_i$, and $\phi_i$ represent the transverse momentum, pseudorapidity, and azimuthal angle of the $i$th jet, and $\hat{n}_{T}$ is the unit vector that maximizes the sum of the projections of $\vec{p}_{T,i}$. The transverse thrust axis $\hat{n}_{T}$ and the beam form the so-called event plane. Based on the direction of $\hat{n}_{T}$, the transverse region is separated into an upper side $\cal{C}_U$, consisting of all jets with $\vec{p}_{T}\cdot\hat{n}_{T}$ $>$ 0, and a lower side $\cal{C}_L$, with $\vec{p}_{T}\cdot\hat{n}_{T}$ $
欧洲核子研究中心大型强子对撞机(CERN-LHC)实验中,针对质心系能量$sqrt{s}=7$ TeV的质子-质子碰撞所记录的多喷注事件,研究了对量子色动力学(QCD)微扰与非微扰相互作用敏感的事件形状变量。实验选取了至少包含一个满足横向动量(transverse momentum, $p_T$)>110 GeV、赝快度绝对值$|eta| < 2.4$的喷注的事件,所用数据样本的积分亮度最高可达5 fb⁻¹。本文针对五种事件形状变量在不同领头喷注横向动量区间内的分布展开分析,并将其与不同QCD蒙特卡洛(Monte Carlo, MC)事件生成器的预言结果进行对比。本文所分析的五种事件形状变量分别为:横向推力$ au_perp$、总喷注展宽$B_{ m tot}$、总喷注质量$ ho_{ m tot}$、总横向喷注质量$ ho^T_{ m tot}$以及三喷注分辨参数$Y_{23}$。在下述公式中,$p_{T,i}$、$eta_i$与$phi_i$分别代表第$i$个喷注的横向动量、赝快度与方位角,$hat{n}_T$是使$vec{p}_{T,i}$的投影之和最大化的单位矢量;该横向推力轴$hat{n}_T$与束流共同构成所谓的事件平面。基于$hat{n}_T$的方向,横向区域被划分为上侧区域$mathcal{C}_U$(包含所有满足$vec{p}_Tcdothat{n}_T > 0$的喷注)与下侧区域$mathcal{C}_L$,其中$vec{p}_Tcdothat{n}_T$



