Related papers: Constraints on scalar and vector leptoquarks from …
We study the Higgs boson decays $h \to Z\gamma$ and $h \to m_VZ$ in a model with vectorlike fermions and $U(1)_X$ symmetry ($U(1)_X$VLFM), where $m_V$ is a vector meson ($\rho,\ \omega,\ \phi,\ J/\psi,\ \Upsilon$). The exotic Yukawa…
The newly discovered resonance at 125 GeV has properties consistent with the Standard Model (SM) Higgs particle, although some production and/or decay channels currently exhibit O(1) deviations. We consider scenarios with a new scalar…
We study the impact of heavy vector-like leptons on several observables in collider and low-energy physics. These states, present in many well-motivated extensions of the Standard Model, can induce lepton flavour violation and non-standard…
We study charged Higgs boson production at future electron-proton colliders in the framework of the Minimal Supersymmetric Standard Model. We focus our attention to the case of single-top production and decay through the channel $t\to…
The possibility to observe a Higgs boson having a mass between 300 and 600 GeV and to measure its couplings to vector bosons and top quark with CMS at the LHC is studied. Six different signatures are analyzed. The possibility to separate…
We present a study of Higgs boson production in vector boson fusion and in association with a vector boson and its decay to two vector bosons, with a focus on the treatment of virtual loops and virtual photons. Our analysis is performed…
We study single production of exotic vectorlike $Y$ quark with electric charge $|Q_{Y}|=4/3$ and its subsequent decay at the High Luminosity LHC (HL-LHC). Most of the vector like quark (VLQ) decays have the electroweak $W$ bosons in the…
A search for scalar and vector leptoquarks coupling to first generation fermions is performed using the e^+p and e^-p scattering data collected by the H1 experiment between 1994 and 2000. The data correspond to a total integrated luminosity…
In this paper we complete our re-assessment of the production of W boson pairs at the LHC, by calculating analytic results for the gg -> W+ W- -> (\nu l l\nu) process including the effect of massive quarks circulating in the loop. Together…
We show that the recent discovery of a new boson at the LHC, which we assume to be a Higgs boson, and the observed enhancement in its diphoton decays compared to the SM prediction, can be explained by a new doublet of charged vector bosons…
We study LHC searches for an extension of the Standard Model (SM) by exploiting an additional Abelian $U_D(1)$ gauge symmetry and a complex scalar Higgs portal. As the scalar is charged under this gauge symmetry, a vector dark matter (VDM)…
We investigate a model of $SU(2) \otimes U(1)$ singlet scalars coupled to Standard Model. We point out that for the case of maximal mixing between singlet scalars and standard Higgs boson the Higgs boson production cross section is smaller…
In a fourth generation model with heavy quarks, the production cross section of the Higgs boson in the gluon-gluon fusion process is significantly increased due to additional quark loops. In a similar way, the partial decay width of the…
We study the off-shell production of the Higgs boson at the LHC to probe Higgs physics at higher energy scales utilizing the process $g g \rightarrow h^{*} \rightarrow ZZ$. We focus on the energy scale dependence of the off-shell Higgs…
Vector-Like Quarks (VLQs) are predicted by several theoretical scenarios of new physics and, having colour quantum numbers, can copiously be produced at the Large Hadron Collider (LHC), so long that their mass is in the testable kinematic…
We derive constraints on the sign of couplings in an effective Higgs Lagrangian using prime principles such as the naturalness principle, global symmetries, and unitarity. Specifically, we study four dimension-six operators, O_H, O_y, O_g,…
We present a comprehensive analysis of low-energy signals of hypothetical scalar leptoquark interactions in lepton and kaon transitions. We derive the most general effective four-fermion Lagrangian induced by tree-level scalar leptoquark…
In this article we probe resonant associated production of a Standard Model Higgs boson with new heavy scalar resonant in proton-proton collisions at a center-of-mass energy $\sqrt{s} = 13$ TeV. The Higgs boson and new scalar resonant are…
We examine new aspects of leptoquark (LQ) phenomenology using effective field theory (EFT). We construct a complete set of leading effective operators involving SU(2) singlets scalar LQ and the SM fields up to dimension six. We show that,…
The pair production cross section for scalar and vector leptoquarks at $ep$ colliders is calculated for the case of photon--gluon fusion. In a model independent analysis we consider the most general $C$ and $P$ conserving couplings of…