Phenomenology of neutron-antineutron conversion

We consider the possibility of neutron-antineutron ($n-\bar{n}$) conversion, in which the change of a neutron into an antineutron is mediated by an external source, as can occur in a scattering process. We develop the connections between $n-\bar{n}$ conversion and $n-\bar{n}$ oscillation, in which a neutron spontaneously tranforms into an antineutron, noting that if $n-{\bar n}$oscillationoccursinatheorywithB-Lviolation,then$n-{\bar n}$conversioncanoccuralso\mathrm{.}Weshowhowanexperimentallimiton$n-{\bar n}$conversioncouldconnectconcretelytoalimiton$n-{\bar n}$ oscillation, and vice versa, using effective field theory techniques and baryon matrix elements computed in the M.I.T. bag model.