Towards a full NNLO Monte Carlo generator for low energy e+e- data into leptons and hadrons.

Abstract

During the last 15 years the Radio MonteCarLow Working Group has been providing valuable support to the development of radiative corrections and Monte Carlo event generators for low energy 𝑒 + 𝑒 − data and 𝜏-lepton decays. While the working group has been operating for more than 15 years without a formal basis for funding, parts of our program have recently been included as a Joint Research Initiative in the group application of the European hadron physics community, STRONG2020, to the European Union, with a more specific goal of creating an annotated database for low-energy hadronic cross sections in 𝑒 + 𝑒 − collisions. In parallel the theory community is continuing its effort towards the realization of improved Monte Carlo generators with for low energy 𝑒 + 𝑒 − data into hadrons. Full NNLO corrections in the leptonic sector are to be combined with an improved treatment of radiative corrections involving pions. This is of relevance for the precise determination of the leading hadronic contribution to the muon 𝑔 −2. We will report on these initiatives.