Collinear Expansion of Cross Sections and the EEC at N3LL' in QCD

by Gherardo Vita (MIT and SLAC)

Thursday 8 Apr 2021, 16:30 → 17:30 Europe/Berlin

Zoom

In this seminar I'll show how to efficiently expand hadronic cross sections in the collinear limit. This method can be used in pp collisions, semi-inclusive DIS (SIDIS) processes, and color singlet decays as the ones resulting from electron-positron annihilation. This technique can be used for the study of different physical observables such as the approximation of rapidity distributions at the LHC, the calculation of N-jettiness beam functions as well as TMDPDFs and fragmentation functions at N3LO. In this talk I'll focus on its application to the calculation of the back-to-back asymptotic of the Energy-Energy Correlation (EEC). I'll present the calculation of this limit at three loops in QCD, matching the order of the results obtained in N=4 sYM, and its resummation at N3LL', which constitutes the highest level of accuracy for the resummation of an event shape to date.