A biased MC for muon production for beam-dump experiments
Stefan Ghinescu (Horia Hulubei National Institute of Physics and Nuclear Engineering, 30 Reactorului, Magurele, 077125, Romania); Babette Döbrich (CERN, Esplanade des Particules 1, Geneva 23, 1211, Switzerland); Elisa Minucci (CERN, Esplanade des Particules 1, Geneva 23, 1211, Switzerland); Tommaso Spadaro (Laboratori Nazionali di Frascati INFN, Via E. Fermi 40, Frascati, 00044, Italy)
The search for feebly-interacting new-physics particles in the MeV-GeV mass range often involves high-intensity beams dumped into thick heavy targets. The challenge of evaluating the expected backgrounds for these searches from first principles is limited by the CPU time needed to generate the shower induced by the primary beam. We present a Monte Carlo biasing method allowing a three orders of magnitude increase in the efficiency for the simulation of the muon production in a 400 GeV/c proton beam-dump setup. At the same time, this biasing method is maintaining nearly every feature of a simulation from first principles.
