Search for relativistic fractionally charged particles in space

Abstract

More than a century after the performance of the oil drop experiment, the possible existence of fractionally charged particles (FCPs) still remains unsettled. The search for FCPs is crucial for some extensions of the Standard Model in particle physics. Most of the previously conducted searches for FCPs in cosmic rays were based on experiments underground or at high altitudes.However, there have been few searches for FCPs in cosmic rays carried out in orbit other than AMS-01 flown by a space shuttle and BESS by a balloon at the top of the atmosphere. In this study, we conduct an FCP search in space based on on-orbit data obtained using the DArk Matter Particle Explorer (DAMPE) satellite over a period of five years. Unlike underground experiments, which require an FCP energy of the order of hundreds of GeV, our FCP search starts at only a few GeV. An upper limit of 6.2 × 10 −10 cm −2 sr −1 s −1 is obtained for the flux. Our results demonstrate that DAMPE exhibits higher sensitivity than experiments of similar types by three orders of magnitude that more stringently restricts the conditions for the existence of FCP in primary cosmic rays.

DArk Matter Particle Explorer: 7 years in Space

“…Search for Fractionally-Charged Particles (FCPs) -hypothetical smoking gun signatures predicted in some extensions of the Standard Model gauge group was published by DAMPE in 2022 [50] and presented at this conference [51]. Until recently, most of the FCP searches were carried out by ground-based experiments at high altitudes, requiring FCP energies of few hundred GeV and higher.…”