McMule -- a Monte Carlo generator for low energy processes

Abstract

McMule, a Monte Carlo for MUons and other LEptons, implements many major QED processes at NNLO (eg. $ee\to ee$, $e\mu\to e\mu$, $ee\to\mu\mu$, $\ell p\to\ell p$, $\mu\to\nu\bar\nu e$) including effects from the lepton masses, making it suitable for predictions for low-energy experiments such as MUonE, CMD-III, PRad, or MUSE. Recently, McMule gained the ability to generate events at NNLO rather than just pre-defined differential distributions. To avoid negative event weights, it employs cellular resampling directly as part of the generation step which further reduces the fraction of negative weights.