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

Susan Gardner, Xinshuai Yan

Research output: Contribution to journalArticlepeer-review

14 Scopus citations


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-n¯ oscillations and of a pattern of particular nucleon–antinucleon conversion processes — all accessible through e-d scattering — namely, selecting from ep→e+p¯ ep→n¯ν¯ en→p¯ν¯ and en→en¯ would reveal that the decay ππ→ee 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 ππ→ee would also reveal the Majorana nature of the neutrino, though the absence of this inference would not preclude it.

Original languageEnglish
Pages (from-to)421-426
Number of pages6
JournalPhysics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics
StatePublished - Mar 10 2019

Bibliographical note

Publisher Copyright:
© 2019


  • Baryon and lepton number violation
  • Majorana dynamics
  • Minimal extensions of the electroweak gauge sector
  • Photon and charged-lepton interactions with hadrons

ASJC Scopus subject areas

  • Nuclear and High Energy Physics


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