论文标题
喷气机在Tevatron和LHC处被较大的假性差距隔开
Jets separated by a large pseudorapidity gap at the Tevatron and at the LHC
论文作者
论文摘要
我们对两个高横向动量($ p_t $)的事件进行了现象学分析,该事件被粒子活性的大型(伪)速度间隔分开,也称为喷气间隙-JET事件。在碰撞能量$ \ sqrt {s} $的限制中,比任何其他动量刻度都要大得多,因此,用巴利茨基 - 菲丁 - kuraev--lipatov(bfkl)扰动量子量子量子量子量子量子量子量子化量子量子(QCCCD)的Partons之间的Partons之间描述了喷气间隙 - 射流过程。 BFKL Pomeron Exchange振幅在近代领先的对数近似情况下重新召集,已嵌入Pythia8 Monte Carlo事件发生器中。标准的QCD Dijet事件以$α_s$匹配的$α_s$与Parton Showers一起模拟,以Powheg+Pythia8匹配。我们将计算与通过1.8、7和13 TEV的质量中心能量的CDF,D0和CMS实验进行了比较。详细研究了理论量表,Parton密度,最终和初始状态辐射效应,多个Parton相互作用以及$ P_T $阈值和粒子在速度差距上的颗粒阈值和粒子的多样性。具有严格的间隙定义(间隙中不允许粒子),大多数分布的形状都得到很好的描述,除了CMS方位角分布在13 TEV处。出人意料地通过毕曲霉中的倍年相互作用来很好地建模生存概率。如果没有倍率相互作用,基于两通道艾科纳尔模型的理论预测与实验数据拟合一致。
We present a phenomenological analysis of events with two high transverse momentum ($p_T$) jets separated by a large (pseudo-)rapidity interval void of particle activity, also known as jet-gap-jet events. In the limit where the collision energy $\sqrt{s}$ is much larger than any other momentum scale, the jet-gap-jet process is described in terms of perturbative pomeron exchange between partons within the Balitsky--Fadin--Kuraev--Lipatov (BFKL) limit of perturbative quantum chromodynamics (QCD). The BFKL pomeron exchange amplitudes, with resummation at the next-to-leading logarithmic approximation, have been embedded in the PYTHIA8 Monte Carlo event generator. Standard QCD dijet events are simulated at next-to-leading order in $α_s$ matched to parton showers with POWHEG+PYTHIA8. We compare our calculations to measurements by the CDF, D0, and CMS experiments at center-of-mass energies of 1.8, 7 and 13 TeV. The impact of the theoretical scales, the parton densities, final- and initial-state radiation effects, multiple parton interactions, and $p_T$ thresholds and multiplicities of the particles in the rapidity gap on the jet-gap-jet signature is studied in detail. With a strict gap definition (no particle allowed in the gap), the shapes of most distributions are well described except for the CMS azimuthal-angle distribution at 13 TeV. The survival probability is surprisingly well modelled by multiparton interactions in PYTHIA8. Without multiparton interactions, theoretical predictions based on two-channel eikonal models agree qualitatively with fits to the experimental data.