The production process of the charged Higgs-boson associated with a W boson at electron-positron colliders is discussed in the two-Higgs-Doublet Model (2HDM) and in the Minimal Supersymmetric Standard Model (MSSM). The process is induced at one-loop level in these models. We examine how much the cross section can be enhanced by quarkand Higgs-loop effects. In the non-SUSY 2HDM, in addition to l...

We study loop-induced parity violating asymmetries in the strong production of polarized top quark pairs at pp and pp̄ colliders. The electroweak O(α) corrections to the helicity amplitudes of qq̄ → tt̄ and gg → tt̄ are evaluated in a two Higgs doublet model (2HDM) and the minimal supersymmetric standard model (MSSM). While observables in top quark pair production receive little contribution from s...

We discuss new physics (NP) contributions to kaon mixing parameter $\varepsilon_K$, direct CP violation $\varepsilon^\prime/\varepsilon$ of $K\to \pi\pi$, and rare decays $K^+\to \pi^+\nu\bar\nu$, $K_L\to \pi^0\nu\bar\nu$ $K_{L, S}\to \mu^+ \mu^- $ in the context general two Higgs doublet model. focus on top quark related exotic couplings, show that simultaneous presence flavor conserving viola...

Dark Matter (DM) density is reduced if entropy production takes place after DM particles abundance frozen out in the early universe. We study a possibility of such reduction due to electroweak phase transition (EWPT). compare scenarios standard model (SM) and its simplest extension, two-Higgs doublet (2HDM). Assuming EWPT second order SM scenario first 2HDM, we calculate release these correspon...

Anomalous moments of the top quark arises from one loop corrections to the vertices t̄tg and t̄tγ . We study these anomalous couplings in different frameworks: effective theories, Standard Model and 2HDM. We use available experimental results in order to get bounds on these anomalous couplings.

The rare K + → π + ν ¯ ν decay is investigated in the context of type II two-Higgs-doublet model (2HDM). By using the existing experimental data of the branching ratio, restrictions on the free parameters of the model m H , and tanβ are obtained: 0.7 ≤ tanβ ≤ 0.8, and 500GeV ≤ m H ≤ 700GeV .

Minimal extensions of the Standard Model (SM), such as so-called Two Higgs Doublet (2HDM), can possess several accidental discrete symmetries whose spontaneous breakdown in early universe usually lead to formation domain walls. We extend an earlier work [arXiv:2006.13273] on this topic by studying more detail analytic properties electrically charged and CP-violating kink solutions $Z_{2}$-symme...

Soft breaking of a symmetry requires an invariance the dimension-4 part Lagrangian and non-trivial variation lower-dimensional part. However, in general, separation between dim-4 is not invariant with respect to basis transformations fields. Therefore, natural question physical meaning soft arises. This problem addressed here framework two-Higgs-Doublet Models (2HDM). It has been shown, within ...

In this letter we study the specific sensitivity and constraints to soft breaking Z2 parameter m12 of Two Higgs Doublet Model (2HDM). is considered here as an input model together with masses bosons, mh, mH, mA, mH±, ratio two vacuum expectation values, tan⁡β, cos⁡(β−α), α β mixing angles CP-even CP-odd sector, respectively. We explore in particular decays lightest boson h photons, assuming: 1)...