Probing baryon number with missing energy

A bstract Quark portal interactions qqqN with a light singlet fermion N make baryon number testable through missing transverse energy (MET). We find that present LHC data constrain scales up to 10 TeV (MET plus jet), 8 TeV (MET plus top) and 11 TeV (MET plus bjet). With increasing mass, or larger portal couplings, N becomes less long-lived, and gives clean displaced vertex signatures, which encourage dedicated searches. We also narrow down viable mesogenesis models with color triplet scalars to a mass range ~ y · 3 TeV (with charm) and ~ y · 5 TeV (charmless) couplings y to b and lighter quarks, a window that can be scrutinized by HL-LHC. Interactions also induce rare decays of type baryon (meson) to meson (baryon) plus invisible, which complement high- p T searches and can prove baryon number violation. We explore charm decays Λ c → ( π , K ) + invisible. Their branching ratios are subject to sizable hadronic uncertainties and require high luminosity flavor facilities such as a Tera-Z facility (FCC-ee, CEPC). Branching ratios of top quarks into one or two b -jets plus N can reach few×10 −6 .