Electroweak baryogenesis and the standard model effective field theory

Abstract

We investigate electroweak baryogenesis within the framework of the Standard Model Effective Field Theory. The Standard Model Lagrangian is supplemented by dimension-six operators that facilitate a strong first-order electroweak phase transition and provide sufficient CP violation. Two explicit scenarios are studied that are related via the classical equations of motion and are therefore identical at leading order in the effective field theory expansion. We demonstrate that formally higher-order dimension-eight corrections lead to large modifications of the matter-antimatter asymmetry. The effective field theory expansion breaks down in the modified Higgs sector due to the requirement of a first-order phase transition. We investigate the source of the breakdown in detail and show how it is transferred to the CP-violating sector. We briefly discuss possible modifications of the effective field theory framework.

Electroweak baryogenesis from temperature-varying couplings

“…This formalism allows us to introduce the operators required to satisfy the Sakharov conditions, as well as modify the SM gauge couplings. The effect of operators required to ensure a first order phase transition and provide new CP violation are well understood, and have been studied extensively in the literature [12][13][14][15][16][17]. The novel aspect of our work is to include dimension-5 operators involving new scalar fields, which change the effective gauge couplings in the early universe.…”

Production of tZH and tZh in 2HDM: Prospects for discovery at the LHC

“…Complex ρ tt provides a generally more robust mechanism for EWBG [7,8]. Having nonzero ρ tt motivates the conventional gg → H → tt scalar resonance search, or gg → Htt → tttt [50], i.e., four-top search.…”

“…The λ matrices are real and diagonal, but the ρ matrices are in general nondiagonal and complex. It was pointed out recently that Oð1Þρ tt and ρ tc can drive electroweak baryogenesis (EWBG) rather efficiently [7,8].…”

Exotic gravitational wave signatures from simultaneous phase transitions

“…Such a cosmic phase transition leaves behind a striking relic gravitational wave spectrum that depends on the strength of the transition, the speed of the transition, the bubble wall velocity and the temperature of the transition. The electroweak phase transition in particular is of interest since a strongly first order electroweak phase transition can catalyze electroweak baryogenesis [9][10][11][12] providing an explanation for matter anti-matter asymmetry observed today [10,11,[13][14][15][16][17][18]. The phenomenology of such PTs have been studied abundantly [19][20][21][22][23][24][25][26][27][28] and the GW production has recently been advanced theoretically [29] and through lattice simulations [30,31].…”