In this work we compute the CP-violating currents of the right-handed stops and Higgsinos, induced by the presence of non-trivial vacuum expectation values of the Higgs fields within the context of the minimal supersymmetric extension of the Standard Model (MSSM) with explicit CP-violating phases. Using the Keldysh formalism, we perform the computation of the currents at finite temperature, in an expansion of derivatives of the Higgs fields. Contrary to previous works, we implement a resummation of the Higgs mass insertion effects to all orders in perturbation theory. While the components of the right-handed stop current j µ t R become proportional to the difference H 2 ∂ µ H 1 − H 1 ∂ µ H 2 (suppressed by ∆β), the Higgsino currents, j µ H i , present contributions proportional to both H 2 ∂ µ H 1 ± H 1 ∂ µ H 2 . For large values of the charged Higgs mass and moderate values of tan β the contribution to the source proportional to H 2 ∂ µ H 1 + H 1 ∂ µ H 2 in the diffusion equations become sizeable, although it is suppressed by the Higgsino number violating interaction rate Γ −1/2 µ . For small values of the wall velocity, 0.04 < ∼ v ω < ∼ 0.1, the total contribution leads to acceptable values of the baryon asymmetry for values of the CP-violating phases ϕ CP in the range 0.04 < ∼ | sin ϕ CP | < ∼ 1. Finally, we comment on the relevance of the latest results of Higgs searches at LEP2 for the mechanism of electroweak baryogenesis within the MSSM. † Present address:

We compute the tunneling probability from the symmetric phase to the true vacuum, in the first order electroweak phase transition of the MSSM, and the corresponding Higgs profiles along the bubble wall. We use the resummed two-loop temperature-dependent effective potential, and pay particular attention to the light stop scenario, where the phase transition can be sufficiently strongly first order not to wipe off any previously generated baryon asymmetry. We compute the bubble parameters which are relevant for the baryogenesis mechanism: the wall thickness and ∆β. The two-loop corrections provide important enhancement effects, with respect to the one-loop results, in the amount of baryon asymmetry.

We present a complete and systematic analysis of the Minkowski extrema of the N = 1, D = 4 Supergravity potential obtained from type II orientifold models that are T-duality invariant, in the presence of generalised fluxes. Based on our previous work on algebras spanned by fluxes, and the so-called no-go theorems on the existence of Minkowski and/or de Sitter vacua, we perform a partly analytic, partly numerical analysis of the promising cases previously hinted. We find that the models contain Minkowski extrema with one tachyonic direction. Moreover, those models defined by the Supergravity algebra so(3, 1) 2 also contain Minkowski/de Sitter minima that are totally stable. All Minkowski solutions, stable or not, interpolate between points in parameter space where one or several of the moduli go to either zero or infinity, the so-called singular points. We finally reinterpret our results in the language of type IIA flux models, in order to show explicitly the contribution of the different sources of potential energy to the extrema found. In particular, the cases of totally stable Minkowski/de Sitter vacua require of the presence of non-geometric fluxes.

We perform a complete classification of the flux-induced 12d algebras compatible with the set of N = 1 type II orientifold models that are T-duality invariant, and allowed by the symmetries of the T 6 /(Z 2 ×Z 2 ) isotropic orbifold. The classification is performed in a type IIB frame, where onlyH 3 and Q fluxes are present. We then study no-go theorems, formulated in a type IIA frame, on the existence of Minkowski/de Sitter (Mkw/dS) vacua. By deriving a dictionary between the sources of potential energy in types IIB and IIA, we are able to combine algebra results and no-go theorems. The outcome is a systematic procedure for identifying phenomenologically viable models where Mkw/dS vacua may exist. We present a complete table of the allowed algebras and the viability of their resulting scalar potential, and we point at the models which stand any chance of producing a fully stable vacuum.

A real singlet scalar, connected to the Standard Model sector through a portal with the Higgs boson, is one of the simplest and most popular models for dark matter (DM). However, the experimental advances in direct and indirect DM searches, together with the latest results from the LHC, have ruled out vast areas of the parameter space of this scenario; and are expected to probe it completely within the next years, ruling it out if no signal is found. Motivated by the simplicity of this model, in this article we address a minimal, renormalizable extension that could evade detection, consisting of the addition of an extra real singlet scalar field in the dark sector. We analyze the physical constraints on the model and show that the new annihilation and/or coannihilation channels involving the extra singlet allow to reproduce the correct DM relic abundance while avoiding the bounds from direct and indirect searches for any DM mass above 50 GeV. We also show that, in some interesting regions of the parameter space, the extra particle can be integrated-out, leaving a "clever" effective theory (just involving the DM particle and the Higgs), that essentially reproduces the results.