In particle physics, majorons (named after Ettore Majorana) are a hypothetical type of Goldstone boson that are theorized to mediate the neutrino mass violation of lepton number or B − L in certain high energy collisions such as
- e− + e− → W− + W− + J
Where two electrons collide to form two W bosons and the majoron J. The U(1)B–L symmetry is assumed to be global so that the majoron isn't "eaten up" by the gauge boson and spontaneously broken. Majorons were originally formulated in four dimensions by Y. Chikashige, R. N. Mohapatra and R. D. Peccei to understand neutrino masses by the seesaw mechanism and are being searched for in the neutrino-less double beta decay process. There are theoretical extensions of this idea into supersymmetric theories and theories involving extra compactified dimensions. By propagating through the extra spatial dimensions the detectable number of majoron creation events vary accordingly. Mathematically, majorons may be modeled by allowing them to propagate through a material while all other Standard Model forces are fixed to an orbifold point.
Further reading 
- Balysh, A.; et al. (1996). "Bounds on new Majoron models from the Heidelberg-Moscow experiment". Physical Review D 54 (5): 3641–3644. arXiv:nucl-ex/9511001. Bibcode:1996PhRvD..54.3641G. doi:10.1103/PhysRevD.54.3641.
- Mohapatra, R. N.; Pérez-Lorenzana, A.; de S. Pires, C. A. (2000). "Neutrino mass, bulk majoron and neutrinoless double beta decay". Physics Letters B 491 (1–2): 143–147. arXiv:hep-ph/0008158. Bibcode:2000PhLB..491..143M. doi:10.1016/S0370-2693(00)01031-5.
- Carone, C. D.; Conroy, J. M.; Kwee, H. J. (2002). "Bulk majorons at colliders". Physics Letters B 538 (1–2): 115–120. arXiv:hep-ph/0204045. Bibcode:2002PhLB..538..115C. doi:10.1016/S0370-2693(02)01943-3.
- Frampton, P. H.; Oh, M. C.; Yoshikawa, T. (2002). "Majoron mass zeros from Higgs triplet vacuum expectation values without a Majoron problem". Physical Review D 66 (3): 033007. arXiv:hep-ph/0204273. Bibcode:2002PhRvD..66c3007F. doi:10.1103/PhysRevD.66.033007.
- Grossman, Y.; Haber, H. E. (2003). "The would-be Majoron in R-parity-violating supersymmetry". Physical Review D 67 (3): 036002. arXiv:hep-ph/0210273. Bibcode:2003PhRvD..67c6002G. doi:10.1103/PhysRevD.67.036002.
- de S. Pires, C. A.; Rodrigues da Silva, P. S. (2004). "Spontaneous breaking of the lepton number and invisible majoron in a 3-3-1 model". European Physical Journal C 36: 397–403. arXiv:hep-ph/0307253. Bibcode:2004EPJC...36..397D. doi:10.1140/epjc/s2004-01949-3.