Lepton pair production in ultraperipheral collisions: Toward a precision test of the resummation formalism
Ding Yu Shao, Cheng Zhang, Jian Zhou, Ya-jin Zhou
Abstract
We present a detailed investigation of the azimuthal asymmetries and acoplanarity in lepton pair production in ultraperipheral collisions (UPCs). These observables provide a unique opportunity to test the soft colliner effective theory resummation formalism, given the exceptionally high photon flux in UPCs, which enables precise measurements of these processes. We improve the accuracy of the previous calculations by including the soft photon contributions beyond the double leading logarithm approximation. Notably, the single logarithmic terms arising from the collinear region are greatly enhanced by the small mass of the leptons. Our findings demonstrate the accessibility of these subleading resummation effects through the analysis of angular correlations in lepton pairs produced in UPCs at the Relativistic Heavy Ion Collider and the Large Hadron Collider.