Multi-W-Z-top Bags, and their Possible Role in Cosmological Baryogenesis

As an amusing incarnation of Nuclear Physics, the gauge bosons W, Z and the top quarks may form collective states bound by Higgs-based attraction. Since Higgs vacuum expectation value (VEV) is significantly modified inside them, they are called “bags”. We argue that creation of such objects can explain certain numerical studies of cosmological baryogenesis. Using as an example a hybrid model, combining inflationary preheating with cold electroweak transition, we identify “spots of unbroken phase” found in numerical studies of this scenario with such W–Z bags. We argue that the baryon number violation should happen predominantly inside these objects, and show that the rates calculated in numerical simulations can be analytically explained using finite-size pure gauge sphaleron solutions, developed previously in the QCD context by Carter, Ostrovsky and Shuryak (COS). Furthermore, we point out significant presence of the top quarks/antiquarks in these bags (which were not included in those numerical studies). We find that tops help to stabilize them for a longer time. Another enhancement of the transition rate comes from the “recycling” of the tops in the topological transition. Although we do not discuss it here, it is highly probable that this scenario would produce CP violation by the usual CKM matrix mechanism large enough to explain the observed baryon asymmetry.