Selection Rules for Baryon Number Nonconservation in Gauge Models

  • R. E. Marshak
  • R. N. Mohapatra


We discuss the selection rules for baryon number nonconserving processes in the context of various gauge models with partial and complete unification of all elementary particle forces. Three separate cases are discussed: (a) Δ(B−L) = 0, Δ(B+L) ≠ 0; (b) Δ(B−L) ≠ 0, Δ(B+L) = 0; and (c) Δ(B−L) ≠ 0 and Δ(B+L) ≠ 0. Observation of \(n - \bar n\) “oscillation” without proton decay with a life-time of ≳ 1030 years would be evidence of “partial unification” with an intermediate mass scale of ~108–109 GeV.


Higgs Boson Selection Rule Baryon Number Proton Decay Gauge Model 
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References and Footnotes

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    This yields ΔL processes such as neutrinoless double β decay and an interesting correlation between neutrino mass and the right-handed W boson, i.e. \({m_\upsilon } \simeq \frac{{{m_\ell }^2}}{{{g_{{m_{{w_r}}}}}}}.\) See R.N. Mohapatra and G. Senjanovic, CCNY-HEP-79/10 (1979).Google Scholar
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    The equivalent of this relation was suggested by A. Gamba, R.E. Marshak and S. Okubo (Proc. Nat. Acad, of Sci.? (1959)) when the consequences of the baryon-lepton symmetry of the weak interaction were first examined. See also paper by R.E. Marshak and R.N. Mohapatra for Maurice Goldhaber Festschrift (New York, 1980 ).Google Scholar
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    We have used the same notation as J.C. Pati and A. Salam (ref. 9) but it is important to stress that the fourth color in our case is (B–L) not L.Google Scholar
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    The extended SU (5) model has also been considered in detail by L.N. Chang and N.P. Chang (to be published).Google Scholar
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    This is the subject of a forthcoming paper by R.N. Mohapatra and G. Senjanovic, to appear as a City College Preprint (1980). It is shown in this paper that to get sin2 0W(mwL) to be about 0.23, while at the same time getting an intermediate mass scale, requires the value mX,Y ≈ 1019 GeV and mWR ≈10 GeV, as well as mX,Y.. mPS. In this case, the proton decay mediated by the gauge bosons is completely suppressed leaving n–n oscillation as a possible dominant mode of baryon non- conservation.Google Scholar
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    HUTP-79/AO29 and HUTP-79/A059. These preprints discuss modifications of the minimal SU(5) model and reach similar conclusions to ours as summarized in Table 1; however, we stress that the new result highlighted by Table 1 is the predicted dominance of the “neutron oscillation” mode in a partial unification model incorporating B-L local symmetry on the electroweak level.Google Scholar

Copyright information

© Plenum Press, New York 1980

Authors and Affiliations

  • R. E. Marshak
    • 1
  • R. N. Mohapatra
    • 2
  1. 1.Virginia Polytechnic Institute and State UniversityBlacksburgUSA
  2. 2.City College of City University of New YorkNew YorkUSA

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