Rational approximants in g-2 of the muon

Abstract

In the absence of direct evidence for physics beyond the Standard Model (BSM), indirect searches play a major role in testing the theory. At present, one of the most prominent examples is the anomalous magnetic moment of the muon, known as g_mu-2. The latest experimental result from the Muon g-2 collaboration, published in 2021, shows a 4.2 sigma tension with the dispersion-relation based determination of this quantity within the Standard Model (SM). However, several aspects of the SM calculation must be scrutinized before this tension can be attributed to BSM effects. In the present project, we aim at reducing the uncertainty on g_mu-2 in the SM applying rational approximants. We will consider purely theoretical aspects of the method as well as applications to hadronic form-factor data and to the recently proposed CERN-MUonE experiment. The use of D-Log Padé approximants, that we have recently reintroduced in the physics literature, should play a central role in this project. (AU)