Searching for fractionally charged particles with DAMPE

The existence of fractionally charged particles (FCP) is foreseen in some extensions to the Standard Model of particle physics, and their detection would be a significant breakthrough. Most of the previous cosmic-rays (CRs) studies are mainly focused on the secondary CRs from the extensive air shower, but there is rarely on-orbit study to search FCP from primary CRs. The DArk Matter Particle Explorer (DAMPE) was launched into space on the 17th December 2015, and it has been working well in space for more than five years with the purpose of measuring CRs and gamma-rays, and as today a large amount of scientific data has been acquired. The FCP is assumed to be a heavy lepton, as a result, the Minimum Ionized Particles (MIPs) are selected. The Geant4 simulations toolkit is used to investigate the signal region and to evaluate selection efficiency of 2/3 FCP in DAMPE. The detailed selection methods are presented and discussed in this work.