Neutron-antineutron oscillation and parity and CP symmetries

Abstract

It is shown that the neutron-antineutron oscillation per se does not necessarily imply CP violation in an effective local Lorentz invariant description of the neutron which preserves CPT, contrary to a recent analysis in the literature. A CP- and baryon number-violating term can be transformed into a CP conserving one, thus rendering the CP violation spurious and unusable in the analysis of baryogenesis, for example. It is also shown that the neutron-antineutron oscillation in a $\Delta B=2$, Lorentz and CPT invariant interaction can occur only when parity is violated, irrespective of the CP properties; when parity is conserved, it is the ordinary quantum transition from neutron to antineutron which takes place. Those statements are proven by explicitly analyzing all the possible combinations with P, C and CP violation or their conservation. Moreover, a suitable combination of P=odd and P=even $\Delta B=2$ interactions in the present model is shown to give rise to the CP preserving mass term for the right-handed neutrino if one replaces the neutron by the neutrino, reinforcing the conclusion.

16 pages

References in corpus (3)

• Experimental search for neutron - mirror neutron oscillations using storage of ultracold neutrons
• Neutrino-antineutrino mass splitting in the Standard Model and baryogenesis
• Neutrino-antineutrino Mass Splitting in the Standard Model: Neutrino Oscillation and Baryogenesis

Cited by in corpus (8)

• CP Violating Baryon Oscillations
• Neutron--Antineutron Oscillations: Discrete Symmetries and Quark Operators
• CPT, CP, and C transformations of fermions, and their consequences, in theories with B-L violation
• Quantum Field Theory of Particle Oscillations: Neutron-Antineutron Conversion
• Neutron-antineutron oscillations beyond the quasi-free limit
• Parity of the neutron consistent with neutron-antineutron oscillations
• Baryon number violation and novel canonical anti-commutation relations
• A quest for new physics inside the neutron