Assisted baryon number violation in 4k+2 dimensions

Abstract

Proton decay in six-dimensions orbifolded on square T2/Z2 is highly suppressed at tree level. This is because baryon number violating (BNV) operators containing only the zero mode of bulk fermions must satisfy the selection rule 32ΔB±12ΔL=0 mod 4. In this article, we show that the above relation does not prohibit mass dimension-six BNV operators containing Kaluza-Klein partners of the bulk fermions. Together with a “spinless” adjoint scalar partner of hypercharge gauge boson (the dark matter candidate), these novel operators generate dark matter assisted proton decay at mass dimension eight. Here, with explicit examples of scalar and vector baryon number violating interactions, we discuss the importance of such ΔB=1=ΔL and ΔB=2=ΔL operators and derive the limit on new physics. Published by the American Physical Society 2024