We consider the possibility of neutron-antineutron ($n-\overline{n}$) 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 $n-\overline{n}$ conversion and $n-\overline{n}$ oscillation, in which a neutron spontaneously transforms into an antineutron, noting that if $n-\overline{n}$ oscillation occurs in a theory with baryon number minus lepton number (B-L) violation, then $n-\overline{n}$ conversion can occur also. We show how an experimental limit on $n-\overline{n}$ conversion could connect concretely to a limit on $n-\overline{n}$ oscillation, and vice versa, using effective field theory techniques and baryon matrix elements computed in the MIT bag model.

• Received 14 November 2017

DOI:https://doi.org/10.1103/PhysRevD.97.056008

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Published by the American Physical Society