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arXiv 1809.03232nucl-exhep-ex
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$\sqrt{s}$ = 7 TeV质子-质子碰撞中的带电喷流截面和碎裂

Charged jet cross section and fragmentation in proton-proton collisions at $\sqrt{s}$ = 7 TeV

ALICE Collaboration

摘要:

本文报道了用ALICE探测器测量的质心能量为$\sqrt{s}=$ 7 TeV的质子-质子碰撞中的微分带电喷流截面和喷流碎裂分布。具有伪快度$\left| η\right| < {\rm 0.5}$的喷流使用反$k_{\rm T}$喷流寻找算法从带电粒子重建,分辨率参数$R$ = 0.4。在横向动量间隔5 $\leq p_{\rm T}^{\rm ch \; jet} <$ 100 GeV/ $c$中测量喷流截面。测量了5 GeV/ $c$ ~ 30 GeV/ $c$四个喷注横向动量区间内喷注带电组分的标度横向动量谱,研究了喷注破碎。测量结果进行了比较,从PYTHIA模型的计算,以及下一个领先的顺序微扰QCD计算与POWHEG + PYTHIA 8。对于整个测量范围的$p_{\rm T}^{\rm ch \; jet}$,带电射流截面由POWHEG描述。对于$p_{\rm T}^{\rm ch \; jet}$ $>$ 40 GeV/ $c$,PYTHIA的计算结果也与测量的带电喷流截面一致。PYTHIA 6模拟描述了15%的碎片分布。PYTHIA 8观察到较大的差异。

英文摘要:

We report the differential charged jet cross section and jet fragmentation distributions measured with the ALICE detector in proton-proton collisions at a centre-of-mass energy $\sqrt{s}=$ 7 TeV. Jets with pseudo-rapidity $\left| η\right| < {\rm 0.5}$ are reconstructed from charged particles using the anti-$k_{\rm T}$ jet finding algorithm with a resolution parameter $R$ = 0.4. The jet cross section is measured in the transverse momentum interval 5 $\leq p_{\rm T}^{\rm ch \; jet} <$ 100 GeV/$c$. Jet fragmentation is studied measuring the scaled transverse momentum spectra of the charged constituents of jets in four intervals of jet transverse momentum between 5 GeV/$c$ and 30 GeV/$c$. The measurements are compared to calculations from the PYTHIA model as well as next-to-leading order perturbative QCD calculations with POWHEG + PYTHIA8. The charged jet cross section is described by POWHEG for the entire measured range of $p_{\rm T}^{\rm ch \; jet}$. For $p_{\rm T}^{\rm ch \; jet}$ $>$ 40 GeV/$c$, the PYTHIA calculations also agree with the measured charged jet cross section. PYTHIA6 simulations describe the fragmentation distributions to 15%. Larger discrepancies are observed for PYTHIA8.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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