Inphysical cosmology,theelectroweak epochwas the period in the evolution of the early universe when the temperature of the universe had fallen enough that thestrong forceseparated from theelectronuclearinteraction, but was still high enough forelectromagnetismand theweak interactionto remain merged into a singleelectroweak interactionabove the critical temperature for electroweak symmetry breaking (159.5±1.5GeV[1] in theStandard Modelof particle physics). Some cosmologists place the electroweak epoch at the start of theinflationary epoch,approximately 10−36seconds after theBig Bang.[2][3][4]Others place it at approximately 10−32seconds after the Big Bang, when the potential energy of theinflatonfield that had driven theinflationof the universe during the inflationary epoch was released, filling the universe with a dense, hotquark–gluon plasma.[5]
Particle interactions in this phase were energetic enough to create large numbers ofexotic particles,includingW and Z bosonsandHiggs bosons.As the universe expanded and cooled, interactions became less energetic, and when the universe was about 10−12seconds old, W and Z bosons ceased to be created at observable rates.[citation needed]The remaining W and Z bosons decayed quickly, and the weak interaction became a short-range force in the followingquark epoch.
The electroweak epoch ended with anelectroweak phase transition,the nature of which is unknown. If first order, this could source a gravitational wave background.[6][7]The electroweak phase transition is also a potential source ofbaryogenesis,[8][9]provided theSakharov conditionsare satisfied.[10]
In the minimalStandard Model,the transition during the electroweak epoch was not a first- or a second-orderphase transitionbut a continuous crossover, preventing anybaryogenesis,[11][12] or the production of an observablegravitational wave background.[6] [7] However, many extensions to the Standard Model includingsupersymmetryand thetwo-Higgs-doublet modelhave a first-order electroweak phase transition (but require additionalCP violation).[citation needed]
See also
editReferences
edit- ^D'Onofrio, Michela; Rummukainen, Kari (2016). "Standard model cross-over on the lattice".Phys. Rev. D.93(2): 025003.arXiv:1508.07161.Bibcode:2016PhRvD..93b5003D.doi:10.1103/PhysRevD.93.025003.hdl:10138/159845.S2CID119261776.
- ^Ryden, B. (2003).Introduction to Cosmology.Addison-Wesley. p.196.ISBN0-8053-8912-1.
- ^Allday, Jonathan (2002).Quarks, Leptons and the Big Bang.Taylor & Francis.p.334.ISBN978-0-7503-0806-9.
- ^Our Universe Part 6: Electroweak Epoch,Scientific Explorer
- ^Lecture 13: History of the Very Early UniverseArchived2012-03-27 at theWayback Machine,Dr. Balša Terzić, Northern Illinois Center for Accelerator and Detector Development
- ^abCaprini, Chiara; et al. (2020). "Detecting gravitational waves from cosmological phase transitions with LISA: an update".Journal of Cosmology and Astroparticle Physics.2020(3): 024.arXiv:1910.13125.Bibcode:2020JCAP...03..024C.doi:10.1088/1475-7516/2020/03/024.S2CID204950387.
- ^abGhiglieri, J.; Jackson, G.; Laine, M.; Zhu, Y. (2020). "Gravitational wave background from Standard Model physics: Complete leading order".Journal of High Energy Physics.2020(7): 092.arXiv:2004.11392.Bibcode:2020JHEP...07..092G.doi:10.1007/JHEP07(2020)092.S2CID216144470.
- ^L. D. McLerran; M. E. Shaposhnikov; N. Turok; M. B. Voloshin (1991). "Why the baryon asymmetry of the universe is approximately 10**-10".Phys. Lett. B.256:451–456.doi:10.1016/0370-2693(91)91794-V.
- ^Morrissey, David E.; Ramsey-Musolf, Michael J. (2012). "Electroweak baryogenesis".New J. Phys.14(12): 12500.arXiv:1206.2942.Bibcode:2012NJPh...14l5003M.doi:10.1088/1367-2630/14/12/125003.S2CID119230032.
- ^A. D. Sakharov(1967)."Violation of CP invariance, C asymmetry, and baryon asymmetry of the universe".Journal of Experimental and Theoretical Physics Letters.5:24–27. Archived fromthe originalon 2019-05-16.Retrieved2020-07-14.and in Russian,A. D. Sakharov(1967)."Violation of CP invariance, C asymmetry, and baryon asymmetry of the universe".ZhETF Pis'ma.5:32–35. Archived fromthe originalon 2019-06-06.Retrieved2020-07-14.republished asA. D. Sakharov (1991)."Violation of CP invariance, C asymmetry, and baryon asymmetry of the universe".Soviet Physics Uspekhi(in Russian and English).34(5): 392–393.Bibcode:1991SvPhU..34..392S.doi:10.1070/PU1991v034n05ABEH002497.
- ^Bergerhoff, Bastian; Wetterich, Christof (1998). "Electroweak Phase Transition in the Early Universe?".Current Topics in Astrofundamental Physics: Primordial Cosmology.Springer Netherlands. pp. 211–240.arXiv:hep-ph/9611462.doi:10.1007/978-94-011-5046-0_6.ISBN978-94-010-6119-3.S2CID13949582.
- ^Kajantie, Keijo; et al. (1996). "The Electroweak Phase Transition: A Non-Perturbative Analysis".Nucl. Phys. B.466(1–2): 189–258.arXiv:hep-lat/9510020.Bibcode:1996NuPhB.466..189K.doi:10.1016/0550-3213(96)00052-1.S2CID119416033.
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