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.
Highlights
First problem is that the electroweak phase transition (EWPT) is a cross-over transition, whereas the required strong first-order transition can only occur for a much lighter Higgs boson than is observed [4,5,6,7]
We investigate electroweak baryogenesis within the framework of the Standard Model Effective Field Theory
In scenarios of electroweak baryogenesis (EWBG) [11,12,13], the scale of BSM physics cannot be much higher than the electroweak scale which makes the scenario more testable
Summary
We begin by defining the SM Lagrangian. We write the Lagrangian in terms of left-handed quark and lepton doublets, qL, and, lL, respectively, and right-handed singlets uR, dR, and eR. QL and yt denote, respectively, the left-handed doublet of the third-generation quarks and the (33)-component of the up-type Yukawa-coupling matrix. For simplicity we consider a purely imaginary coupling CY = icY , with c∗Y = cY This particular choice of dimension-six operators has been well studied [15, 16, 20, 21] and is sometimes called the minimal EWBG scenario [16]. Where eL and ye denote, respectively, the lepton doublet of the first generation and the real electron Yukawa coupling. We will not remove the μ2CDD piece and keep the form of eq (2.9), mainly because it provides a cleaner relation between L(6EOM) and the derivative of the scalar potential
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
