Abstract

The seminar will take place in the Potter Room at DAMPT and will be broadcast via Zoom here.

Abstract: I will discuss the application of Soft Collinear Effective Theory (SCET) to the extraction of the strong coupling constant from e+e- event shape distributions, where state-of-the-art results exhibit a 3-4 sigma discrepancy with respect to the PDG world average. After introducing event shape distributions and the SCET resummation formalism we use to study them, I will then focus on the canonical ‘Thrust’ variable, and on the phenomenological treatment of non-perturbative effects stemming from the soft sector. In particular, I will show that equivalently well-defined renormalon subtraction schemes can lead to significant shifts in the extracted values of the strong coupling, when studying two-parameter fits in the dijet region. After discussing other generic systematics associated to extractions (and their potential impact on results), I hope to briefly mention novel (non-)perturbative extraction opportunities using the ‘Angularities’ class of observables, which generalizes the Thrust variable.