Search for new charged particle in mass interval 2–100 MeV

Publications, 11 April 2023

We offer to your attention a preprint “Search for new charged particle in mass interval 2–100 MeV” Р1-2022-62 issued by the JINR Publishing Department. The authors are Maya Anikina, Vladimir Nikitin, and Victor Rikhvitskiy.

The regularity of the e, μ, τ lepton mass distribution is proposed, indicating the possibility of the existence of a new state (“heavy” electron) with a mass of ∼ 8 MeV. To search for it, ∼ 55 thousand stereo photos from the 2-m propane bubble chamber were scanned. The chamber is exposed in a 10-GeV proton beam at the JINR Synchrophasotron. The events of the γ-quantum conversion into a pair of charged particles are analysed. 47 anomalous events were found in which one particle of the pair stops in the volume of the chamber, has an increased track density at the end of the range and, upon identification, detects a mass of ∼ 8 MeV. The average value of the mass of the new particle is (8.6 ± 3.0) MeV.

The study has been carried out at the Veksler and Baldin Laboratory of High Energy Physics JINR.