Generation of hypermagnetic helicity and leptogenesis in the early Universeстатья
Статья опубликована в высокорейтинговом журнале
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Дата последнего поиска статьи во внешних источниках: 26 сентября 2016 г.
Аннотация:We study hypermagnetic helicity and lepton asymmetry evolution in the plasma of the early Universe before the electroweak phase transition accounting for chirality flip processes via inverse Higgs decays and sphaleron transitions which violate the left lepton number and wash out the baryon asymmetry of the Universe (BAU). In the scenario where the right electron asymmetry supports the BAU alone through the conservation law B/3−LeR=const at temperatures T>TRL≃10 TeV, the following Universe cooling leads to the production of a nonzero left lepton (electrons and neutrinos) asymmetry. This is due to the Higgs decays becoming faster when entering the equilibrium at T=TRL, with the Universe expansion, ΓRL∼T>H∼T2, resulting in the parallel evolution of the right and left electron asymmetries at T<TRL through the corresponding Abelian anomalies in the standard model in the presence of a seed hypermagnetic field. The hypermagnetic helicity evolution proceeds in a self-consistent way with the lepton asymmetry growth. The role of sphaleron transitions in decreasing the left lepton number turns out to be negligible in a given scenario. The hypermagnetic helicity plays a key role in lepto-/baryogenesis in our scenario, and the more hypermagnetic field gets closer to the maximum helical one the faster the BAU grows to the observable value, Bobs∼10−10