Speaker
Dr
Rikab Gambhir
(Massachusetts Institute of Technology)
Description
Fixed-order perturbative calculations for physical cross sections can suffer from non-physical artifacts: they can be non-finite, non-positive, non-normalizable, and susceptible to large logarithmic corrections. We propose a framework that, given a fixed-order perturbative expression for an observable to some finite order in $\alpha$, will ``resum'' the expression in a way that is guaranteed to be finite, positive, normalized, and match the original expression order-by-order. Moreover, our ansatz parameterizes all possible finite, positive, and normalized completions consistent with the original fixed-order expression, including but not limited to N$^n$LL expressions.
Author
Dr
Rikab Gambhir
(Massachusetts Institute of Technology)
Co-author
Dr
Radha Mastandrea
(Berkeley)