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arXiv 2504.03431hep-exnucl-ex
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质子-质子碰撞中粲标记喷注的能量-能量关联子($\mathbf{\sqrt{s} = 13}$ TeV)

Energy-energy correlators in charm-tagged jets in proton-proton collisions at $\mathbf{\sqrt{s} = 13}$ TeV

ALICE Collaboration

AI总结:

本文首次测量了13 TeV质子-质子碰撞中粲标记喷注的能量-能量关联子,发现粲喷注EEC振幅显著受抑而峰位相似,揭示了Casimir因子与死锥效应的复杂相互作用,为重夸克喷注模型提供了新约束。

摘要:

本文首次测量了质子-质子碰撞在$\sqrt{s} = 13$ TeV下粲标记喷注的能量-能量关联子(EEC)。EEC探究QCD辐射结构,为涉及粲夸克的粒子簇射中质量相关效应提供了独特测试,并深入揭示了包括强子化过程在内的非微扰现象。针对横动量在$10 < p_{\rm T} < 30$ GeV/$c$范围内的粲标记喷注和未标记(包含)喷注测量了EEC,此区间粲夸克质量效应显著。与包含喷注相比,我们观察到粲喷注中EEC振幅显著受抑,这与大质量夸克辐射受抑的QCD基本预言一致。尽管振幅差异显著,粲喷注与包含喷注EEC的观测峰位却相似,表明QCD粒子簇射中Casimir因子(区分夸克和胶子喷注)与夸克质量(死锥)效应以及随后的强子化效应之间存在复杂相互作用。与次领头阶计算及多种蒙特卡洛事件产生子的比较显示,该可观测量对粒子簇射中的质量效应及强子化过程均高度敏感。这些结果为重夸克喷注理论模型提供了新约束,并为QCD中部分子到强子转变提供了见解。

英文摘要:

In this letter, we present the first measurement of the energy-energy correlator (EEC) in charm-tagged jets from proton-proton (pp) collisions at $\sqrt{s} = 13$ TeV. EECs probe the structure of QCD radiation, providing a unique test of mass-dependent effects in parton showers involving a charm quark and offering a distinct view into non-perturbative phenomena, including the hadronization process. The EEC is measured for charm-tagged jets and flavor-untagged (inclusive) jets with transverse momenta of $10 < p_{\rm T} < 30$ GeV/$c$, where charm-quark mass effects are significant. We observe a significant suppression of the EEC amplitude in charm jets compared to inclusive ones, consistent with the expected suppression of radiation from massive quarks -- a fundamental prediction of QCD. Despite the significant amplitude difference, the observed peak positions of the charm and inclusive-jet EEC are similar, indicating a complex interplay between Casimir factor (differentiating quark and gluon jets), and quark-mass (dead-cone) effects in the QCD parton shower as well as subsequent hadronization effects. Comparisons with next-to-leading order calculations and various Monte Carlo event generators reveal the sensitivity of this observable to both mass effects in the parton shower and hadronization process. These results provide new constraints on theoretical models of heavy-quark jets and offer insights into the parton-to-hadron transition in QCD.

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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