Processes that break baryon number by two units and the Majorana nature of the neutrino

Abstract

We employ the simplest possible models of scalar-fermion interactions that are consistent with the gauge symmetries of the Standard Model and permit no proton decay to analyze the connections possible among processes that break baryon number by two units. In this context we show how the observation of $n$-$\bar{n}$ oscillations and of a pattern of particular nucleon-antinucleon conversion processes --- all accessible through e-d scattering --- namely, selecting from $e^{-}p\to e^{+}\bar{p}$, $e^{-}p\to \bar{n}\bar{\nu }$, $e^{-}n\to \bar{p}\bar{\nu }$, and $e^{-}n\to e^{-}\bar{n}$ would reveal that the decay ${\pi }^{-}{\pi }^{-}\to e^{-}{e}^{-}$ must occur also. This latter process is the leading contribution to neutrinoless double beta decay in nuclei mediated by new short-distance physics, in contrast to that mediated by light Majorana neutrino exchange. The inferred existence of ${\pi }^{-}{\pi }^{-}\to e^{-}{e}^{-}$ would also reveal the Majorana nature of the neutrino, though the absence of this inference would not preclude it.

16 pages, explanatory figure and discussion, with analysis of existing phenomenological constraints, added; version to appear in Physics Letters B

References in corpus (14)

• New Fixed-Target Experiments to Search for Dark Gauge Forces
• A Survey of Lepton Number Violation Via Effective Operators
• Dark Sectors 2016 Workshop: Community Report
• Simplified models with baryon number violation but no proton decay
• Post--Sphaleron Baryogenesis
• Search for new physics in events with same-sign dileptons and b-tagged jets in pp collisions at sqrt(s) = 7 TeV
• Magnetic Fields in the Milky Way
• Neutrino Mass Hierarchy and neutron-anti-neutron Oscillation from Baryogenesis
• Diquark Higgs at LHC
• Unified TeV Scale Picture of Baryogenesis and Dark Matter
• Search for dinucleon decay into pions at Super-Kamiokande
• Determining Majorana Nature of Neutrino from Nucleon Decays and n-nbar oscillations
• Dinucleon and Nucleon Decay to Two-Body Final States with no Hadrons in Super-Kamiokande
• Proton annihilation at hadron colliders and Kamioka: high-energy versus high-luminosity

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• How Macroscopic Limits on Neutron Star Baryon Loss Yield Microscopic Limits on Non-Standard-Model Baryon Decay
• An EFT toolbox for baryon and lepton number violating dinucleon to dilepton decays
• $\Delta B=2$ neutron decay into antiproton mode $n\to \bar{p}{e}^{+}\nu (\bar{\nu })$
• Simple models with both baryon and lepton number violation by two units
• Baryon number violating hydrogen decay
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• Scientific Opportunities at the ARIEL Electron Linac