Evolution of cosmological baryon asymmetries. I. The role of gauge bosons

J. N. Fry, Keith A. Olive, Michael S. Turner

Research output: Contribution to journalArticlepeer-review

106 Scopus citations


The time evolution of the baryon asymmetry (knBs) due to the interactions of a superheavy gauge boson (mass MX∼1015 GeV, coupling strength α∼145) is obtained by numerically integrating the Boltzmann equations. Particle interactions in the very early universe (t10-35 sec) are assumed to be described by the SU(5) grand unification theory. To a good approximation the results depend upon one parameter, K2.9×1017 α GeVMX. If C and CP are not violated in the decays of the superheavy boson no asymmetry develops, and any initial baryon asymmetry is reduced by a factor of ≅exp(-5.5K). If both C and CP are violated then an initially symmetrical universe evolves a baryon asymmetry which today corresponds to knBs≅7.8×10-3ε[1+(16K)1.3], where ε2 is the baryon excess produced when an X-X̄ pair decays. Decays and inverse decays of superheavy bosons are primarily responsible for these results (as Weinberg and Wilczek suggested); however for K1 baryon production falls off much less rapidly than they had expected. A gauge boson of mass 3×1014 GeV could have generated the observed asymmetry knBs≅10-9.8±1.6 if ε≅10-4.3±1.6. In a companion paper the role of Higgs bosons is considered.

Original languageEnglish (US)
Pages (from-to)2953-2976
Number of pages24
JournalPhysical Review D
Issue number12
StatePublished - 1980

Bibliographical note

Copyright 2015 Elsevier B.V., All rights reserved.

Fingerprint Dive into the research topics of 'Evolution of cosmological baryon asymmetries. I. The role of gauge bosons'. Together they form a unique fingerprint.

Cite this