Fast simulation of muons produced at the SHiP experiment using Generative Adversarial Networks

: This paper presents a fast approach to simulating muons produced in interactions of the SPS proton beams with the target of the SHiP experiment. The SHiP experiment will be able to search for new long-lived particles produced in a 400 GeV / c SPS proton beam dump and which travel distances between fifty metres and tens of kilometers. The SHiP detector needs to operate under ultra-low background conditions and requires large simulated samples of muon induced background processes. Through the use of Generative Adversarial Networks it is possible to emulate the simulation of the interaction of 400 GeV / c proton beams with the SHiP target, an otherwise computationally intensive process. For the simulation requirements of the SHiP experiment, generative networks are capable of approximating the full simulation of the dense fixed target, offering a speed increase by a factor of O( 10 6 ) . To evaluate the performance of such an approach, comparisons of the distributions of reconstructed muon momenta in SHiP’s spectrometer between samples using the full simulation and samples produced through generative models are presented. The methods discussed in this paper can be generalised and applied to modelling any non-discrete multi-dimensional distribution. A significant improvement was achieved by starting the first section of the muon shield within the hadron stopper by integrating a coil which magnetises the iron shielding blocks. The SHiP detector itself incorporates two complementary apparatuses, the Scattering and Neutrino Detector (SND), and the Hidden Sector (HS) spectrometer. The SND will search for LDM scattering and perform neutrino physics. It is made of an emulsion spectrometer located inside a single long magnet with a field above 1.2T in the entire volume, and a muon identification system. The emulsion spectrometer is a hybrid detector consisting of alternating layers of an absorber, nuclear emulsion films and fast electronic trackers. The absorber mass totals ⇠ 10 tonnes. The HS decay spectrometer aims at measuring the visible decays of HS particles by reconstructing their decay vertices in a 50m long decay volume. In order to eliminate the background from neutrinos