Chen Hao, Moult Ian, Zhu Hua Xing
Zhejiang Institute of Modern Physics, Department of Physics, Zhejiang University, Hangzhou 310027, China.
SLAC National Accelerator Laboratory, Stanford University, California 94309, USA.
Phys Rev Lett. 2021 Mar 19;126(11):112003. doi: 10.1103/PhysRevLett.126.112003.
Collimated sprays of hadrons, called jets, are an emergent phenomenon of quantum chromodynamics (QCD) at collider experiments, whose detailed internal structure encodes valuable information about the interactions of high energy quarks and gluons and their confinement into color-neutral hadrons. The flow of energy within jets is characterized by correlation functions of energy flow operators, with the three-point correlator being the first correlator with nontrivial shape dependence, playing a special role in unraveling the dynamics of QCD. In this Letter, we initiate a study of the three-point energy correlator to all orders in the strong coupling constant, in the limit where two of the detectors are squeezed together. We show that, by rotating the two squeezed detectors with respect to the third by an angle ϕ, a cos(2ϕ) dependence arising from the quantum interference between intermediate virtual gluons with +/- helicity is imprinted on the detector. This can be regarded as a double slit experiment performed with jet substructure, and it provides a direct probe of the ultimately quantum nature of the substructure of jets and of transverse spin physics in QCD. To facilitate our all-orders analysis, we adopt the operator product expansion (OPE) for light-ray operators in conformal field theory and develop it in QCD. Our application of the light-ray OPE in real world QCD establishes it as a powerful theoretical tool with broad applications for the study of jet substructure.
被称为喷注的强子准直束流是对撞机实验中量子色动力学（QCD）的一种涌现现象，其详细的内部结构编码了有关高能夸克和胶子相互作用以及它们被禁闭成色中性强子的宝贵信息。喷注内的能量流由能量流算符的关联函数来表征，三点关联函数是第一个具有非平凡形状依赖性的关联函数，在揭示QCD动力学方面起着特殊作用。在这篇快报中，我们在两个探测器挤压在一起的极限情况下，对强耦合常数的所有阶次的三点能量关联函数展开研究。我们表明，通过将两个挤压探测器相对于第三个探测器旋转角度ϕ，由具有±螺旋性的中间虚胶子之间的量子干涉产生的cos(2ϕ)依赖性会印刻在探测器上。这可以看作是用喷注子结构进行的双缝实验，它为喷注子结构的最终量子性质以及QCD中的横向自旋物理提供了直接探测。为便于我们进行所有阶次的分析，我们采用共形场论中光线算符的算符乘积展开（OPE）并在QCD中加以发展。我们在实际的QCD中对光线OPE的应用将其确立为一种强大的理论工具，在喷注子结构研究中有广泛应用。
