标题： 在小的$x$区域用横向能量-能量关联探针Sivers不对称性 显示英文标题

标题： Probing the Sivers Asymmetry with Transverse Energy-Energy Correlators in the Small-$x$ Regime

摘要： 我们研究了电子-离子对撞机（EIC）中小的$x$区域内极化和非极化靶的横向能量-能量关联函数（TEEC）。聚焦于近似背对背的电荷产生过程中的强子-电子对，我们应用了横向动量依赖（TMD）因子化公式，该公式包含了事件形状可观测量的TMD演化，并用小的$x$双色振幅展开它们。这使我们能够用C奇异数为奇的相互作用（对应于奇eron交换）来表示质子横向极化情况下的TEEC。由于小的$x$夸克Sivers函数的电荷共轭奇异性，我们将最终强子态的求和限制为正负电荷强子分别考虑。我们在EIC上给出了TEEC Sivers不对称性的数值预测，发现不对称性的大小在$0.1 \%$数量级。这一通道为检验仍然很大程度上未约束的奇eron振幅提供了一个有前景的途径。 显示英文摘要

摘要： We investigate transverse energy-energy correlators (TEECs) for both polarized and unpolarized targets in the small-$x$ regime at the Electron-Ion Collider (EIC). Focusing on the approximately back-to-back electroproduction of a hadron-electron pair, we apply transverse-momentum-dependent (TMD) factorization formulas that incorporate TMD evolution for both event-shape observables and expand them in terms of the small-$x$ dipole amplitude. This allows us to write the TEEC off the transversely polarized proton in terms of a C-odd interaction, corresponding to an odderon exchange. Due to the charge-conjugation-odd nature of the small-$x$ quark Sivers function, we restrict the sum over final hadronic states to positively and negatively charged hadrons separately. We present numerical predictions for the TEEC Sivers asymmetry at the EIC and find the magnitude of the asymmetry to be on the $0.1 \%$ level. This channel offers a promising avenue for benchmarking the still largely unconstrained odderon amplitude.