Analysis of Monte Carlo Simulations for the J-PARC E50 Mu-ID Detector Extension

The inner dynamics of a proton remain a mystery of modern science. Understanding quark-gluon interactions in protons through analysis of collisions is essential to solving this puzzle, and this can be done by looking at the exclusive meson-induced Drell-Yan process. To study this process, an extension is proposed to the J-PARC E50 Charmed Baryon Spectroscopy experiment. Analysis of ROOT files (produced by GEANT4 simulations of the extension's hadron absorber) was done with C++ macros that matched up dimuon pairs, smeared the simulated data to match experimental uncertainties, and used gaussian fitting techniques to identify a relevant missing mass window around the nucleon mass. These steps ensured that the signal data was only Drell-Yan dimuons, and were repeated for background simulations as well. Counts of events were recorded, and the signal to background (S/B) ratio was studied for hadron absorber length dependence. Fewer background events were simulated than required by the process cross sections, so weighted distributions were used to ensure the S/B ratio was compatible with expectations. This ratio was optimized at a length of 13 centimeters. While limitations of time and computational power suggest this number is not fully accurate, the analysis framework developed can be applied to new simulations to obtain a better result. This research was conducted as a part of NSF-funded PIRE-GEMADARC, at the Academia Sinica Institute of Physics in Taipei.