Light particles with baryon and lepton numbers

We consider light new particles χ and ϕ that carry baryon and lepton numbers. If these particles are lighter than nucleons they lead to exotic decays such as p→π+χ and p→e+ϕ, not yet fully constrained by dedicated searches. For χ and ϕ masses in the GeV range, proton decays are kinematically forbidden but other decays of the forms baryon → meson + χ, meson → baryon + χ¯, and baryon → anti-lepton + ϕ involving heavy initial hadrons are allowed. This opens up the possibility to search for apparent baryon number violation not just in underground experiments such as Super-Kamiokande and DUNE but also in decays of heavy hadrons in charm and B factories.