LAPTH, UMR5108, Université de Savoie, CNRS, BP 110, 74941 Annecy-le-Vieux cedex, France.
Phys Rev Lett. 2010 Aug 6;105(6):062002. doi: 10.1103/PhysRevLett.105.062002.
A scaling law analysis of the world data on inclusive large-p(⊥) hadron production in hadronic collisions is carried out. Significant deviations from leading-twist perturbative QCD predictions at next-to-leading order are observed, particularly at high x(⊥)=2p(⊥)/sqrt[s]. In contrast, the production of prompt photons and jets exhibits near-conformal scaling behavior in agreement with leading-twist expectations. These results indicate a non-negligible contribution of higher-twist processes in large-p(⊥) hadron production, where the hadron is produced directly in the hard subprocess, rather than by quark and gluon fragmentation. Predictions for the scaling exponents at RHIC and LHC are given. Triggering on isolated large-p(⊥) hadron production will enhance the higher-twist processes. We also note that the use of isolated hadrons as a signal for new physics can be affected by the presence of direct hadron production.
对强子碰撞中包含大横动量 p⊥的整体强子产生的世界数据进行了标度律分析。在次领头阶，观察到与领头扭量微扰 QCD 预测的显著偏离，特别是在高横动量 x⊥=2p⊥/√s 处。相比之下，快光子和喷注的产生表现出近共形标度律行为，与领头扭量的预期相符。这些结果表明，在大横动量 p⊥强子产生中，高阶扭过程有不可忽视的贡献，其中强子是在硬子过程中直接产生的，而不是通过夸克和胶子碎裂产生的。给出了在 RHIC 和 LHC 上的标度指数预测。对孤立大横动量 p⊥强子产生的触发将增强高阶扭过程。我们还注意到，孤立强子作为新物理信号的使用可能会受到直接强子产生的影响。
