Related papers: Constraining wrong-sign $hbb$ couplings with $h \r…
We perform a model-independent study of new physics effects in the Higgs decay $h \to \Upsilon \gamma$, focusing on scenarios that spoil the accidental cancellation between the direct and indirect amplitudes. After imposing all existing…
We analyse the possibility that, in two Higgs doublet models, one or more of the Higgs couplings to fermions or to gauge bosons change sign, relative to the respective Higgs Standard Model couplings. Possible sign changes in the coupling of…
We consider two Higgs doublet models with a softly broken U(1) symmetry, for various limiting values of the scalar mixing angles $\alpha$ and $\beta$. These correspond to the Standard Model Higgs particle being the lighter CP-even scalar…
We point out the importance of the decay channels $A\to Zh$ and $H\to VV$ in the wrong-sign limit of the Two-Higgs-Doublet Model (2HDM) of type II. They can be the dominant decay modes at moderate values of $\tan\beta$, even if the…
It has been pointed out recently that current experiments still allow for a two Higgs doublet model where the $h b \bar{b}$ coupling ($k_D m_b/v$) is negative; a sign opposite to that of the Standard Model. Due to the importance of delayed…
We consider the two-Higgs-doublet model as a framework in which to evaluate the viability of scenarios in which the sign of the coupling of the observed Higgs boson to down-type fermions (in particular, $b$-quark pairs) is opposite to that…
The recently discovered 125 GeV boson appears very similar to a Standard Model Higgs, but with data favoring an enhanced h to gamma gamma rate. A number of groups have found that fits would allow (or, less so after the latest updates,…
The study of the Higgs boson properties is one of the most relevant activities in current particle physics. In particular, the Higgs boson couplings to third generation fermions is an important test of the mechanism of mass generation. In…
We discuss scenarios with wrong-sign (WS) Yukawa couplings for the discovered Higgs boson in the Yukawa-aligned two Higgs doublet model. In the WS scenario, Yukawa couplings for down-type quarks and/or charged leptons have an opposite sign…
A sign change in the Higgs couplings to fermions and massive gauge bosons is still allowed in the framework of two-Higgs doublet models (2HDM). In this work we discuss the possible sign changes in the Higgs couplings to fermions and gauge…
It is well know that the precise measurement of $H\to\gamma\gamma$ can generate two degenerate parameter spaces of $H\gamma\gamma$ anomalous coupling. We propose to utilize the exclusive Higgs rare decays $H\to\Upsilon(ns)+\gamma$ to break…
We confront the most common CP-conserving 2HDM with the LHC data analysed so far while taking into account all previously available experimental data. A special allowed corner of the parameter space is analysed - the so-called wrong-sign…
In the decoupling limit of a non-minimal Higgs sector, the lightest CP-even Higgs boson (h) is indistinguishable from the Standard Model (SM) Higgs boson. In the two-Higgs-doublet sector of the MSSM, the approach to the decoupling limit…
In left-right symmetric models, large contributions to the decay amplitude $b \rightarrow s+ \gamma$ can arise from the mixing of the $W_L$ and $W_R$ gauge bosons as well as from the charged Higgs boson. These amplitudes are enhanced by the…
Recent re-evaluations of the Standard Model (SM) contribution to ${\mathcal Br(b\to s\gamma)$ hint at a positive correction from new physics. Since a charged Higgs boson exchange always gives a positive contribution to this branching ratio,…
We investigate Higgs boson decay into two photons in the type-II seesaw model. The rate of $h\to \gamma\gamma$ gets suppressed/enhanced in this model compared to the Standard Model (SM) due to the presence of the singly and doubly charged…
A study of two-Higgs-doublet models (2HDM) in the decoupling limit reveals the existence of parameter configurations with a large triple-Higgs self-coupling as the only low-energy trace of a departure from a Standard Model (SM) Higgs…
The magnitudes of the couplings of the scalar resonance at 125 GeV with the SM particles are found to be consistent with those of the SM Higgs boson. However, the signs are not experimentally determined in most of the cases, a prime example…
The LHC sensitivity to an anomalous Higgs coupling to the top quark in the Higgs-top associated production is analyzed. Thanks to the strong destructive interference in the t-channel for standard model couplings, this process can be very…
A sequential fourth generation is known to be excluded because the non-decoupling contribution to $\kappa_g$, the Higgs coupling modifier with a gluon pair, is unacceptably large. Recently a new way to save the model was suggested in the…