All-order results in gauge theories

by Leonardo Vernazza (INFN, Torino)

Monday 11 Apr 2022, 14:30 → 16:00 Europe/Rome

Precision physics at hadron colliders represents a valid opportunity to find New Physics, in the form of small deviations from predictions made within the Standard Model. To this end, physicists are hard at work to improve our ability to provide accurate theoretical predictions. The calculation of scattering processes is largely based on perturbation theory. In this context, one faces several challenges. On the one hand, fixed-order calculations within current technology becomes incredibly involved already at second order in perturbation theory. On the other hand, in presence of scattering processes involving multiple scales, which is a common circumstance at hadron colliders, perturbation theory is often not enough: large logarithms of the ratio of these scales appear, which spoil the convergence of the perturbative expansion. In this case, the large logarithmic contribution needs to be summed to all orders, in order to obtain reliable results, a process that is known as resummation. 

My work within the Fellini project deals with developing new calculation techniques for resummation. I will illustrate recent results, focusing on large logarithms appearing in kinematic limits of scattering processes, such as the high-energy and the threshold limits. Summing large logarithms poses a very interesting theoretical problem, because it requires to understand all-order properties of gauge theories. As such, I will show how ideas developed within resummation feeds into several aspects of quantum field theory, providing also important results for fixed order perturbation theory and effective field theories.

Meeting ID: 694 9192 9100

Passcode: 095417

https://cern.zoom.us/j/69491929100?pwd=eEVGRVFzZjREYjZSMm9pNFJYZVZZUT09

Fellini-2022.pdf