Related papers: Off-shell effects in Higgs processes at a linear c…
In this manuscript, we study the general scalar leptoquark contributions to the $gg\rightarrow Zh$ process at one-loop level. We find that the contributions only show up for the off-diagonal Higgs and $Z$ boson interactions with scalar…
Off-shell Higgs at the high mass tail may shed light on the underlying mechanism of the electroweak symmetry breaking. Due to the large cancellation in the standard model (SM) between the box and Higgs-mediated triangle diagrams, the $gg\to…
This paper presents the studies of the background contribution to the $H \rightarrow 4l$ searches originating from the processes of off-shell (virtual) photon emissions and their conversions into lepton pairs accompanying the production of…
The indirect determination of the total width of the detected Higgs boson that is carried out by the experimental collaborations at the LHC relies on the assumption that the coupling modifiers for the on-shell and off-shell couplings are…
We report on the calculation of the next-lo-leading order QCD corrections to Higgs boson production and decay in association with top quarks. We consider leptonic decays of top quarks leading to the hadronic process $pp\to e^+\nu_e\,…
We calculate the cross-section of the near-threshold off-shell $ZZZ$ and $ZW^+W^-$ production at the International Linear Collider taking into account their instability and the principal part of NLO corrections. The calculations are…
A measurement of off-shell Higgs boson production in the $H^*\to ZZ\to 4\ell$ decay channel is presented. The measurement uses 140 fb$^{-1}$ of proton-proton collisions at $\sqrt{s}=13$ TeV collected by the ATLAS detector at the Large…
We calculate all the experimentally relevant branching ratios of the Higgs bosons of the Minimal Supersymmetric Standard Model, paying particular attention to the contributions from below--threshold decays. We show that in some cases these…
Interference effects play an important role in Electroweak Physics. They are responsible for the restoration of unitarity al large energies. When, as is often the case, higher order corrections are only available for some particular…
We present state-of-the-art predictions for $t\bar{t}\gamma$ and $t\bar{t}Z(Z \to \nu_\ell\bar{\nu}_\ell)$ production in the fully leptonic channel at the LHC. The first process can provide key information on the strength and structure of…
We point out that existing measurements of $pp \to ZZ$ cross-section at the LHC in a broad range of ZZ invariant masses allow one to derive a model-independent upper bound on the Higgs boson width, thanks to strongly enhanced off-shell…
We extend the study of Higgs boson couplings in the "golden" $gg\to H \to ZZ^\ast \to 4\ell$ channel in two important respects. First, we demonstrate the importance of off-shell Higgs boson production ($gg\to H^\ast \to ZZ \to 4\ell$) in…
We present NLO electroweak corrections to Higgs production in association with off-shell top-antitop quark pairs. The full process $\text{p}\text{p}\to\text{e}^+\nu_{\text{e}} \mu^-\bar{\nu}_\mu\text{b}\bar{\text{b}} \text{H}$ is…
Results for next-to-leading order QCD corrections to the pp(p\bar{p}) -> t \bar{t} -> W^+W^- b\bar{b} -> e^{+} \nu_{e} \mu^{-} \bar{\nu}_{\mu} b \bar{b} +X processes with complete off-shell effects are presented for the first time. Double-,…
In this study we consider an effective model by introducing two hypothetical real scalars, $H$ and $\chi$ - a dark matter candidate, where the masses of these scalars are $2 m_h < m_H < 2 m_t$ and $m_\chi \approx m_h/2$ with $m_h$ and $m_t$…
Precision studies of the properties of the top quark represent a cornerstone of the LHC physics program. In this contribution we focus on the production of $t\bar{t}$ pairs in association with one hard jet and in particular on its…
The phenomenology of unstable particles, including searches and exclusion limits at the LHC, depends significantly on its lineshape. When the width of the resonance is large with respect to its mass, off-shell effects become relevant and…
In these proceedings we discuss the importance of higher-order corrections and off-shell effects for the calculation of signal strength exclusion limits in $t\bar{t}+$DM searches at the Large Hadron Collider. We present limits for the…
We present a method to compute off-shell effects for processes involving resonant particles at hadron colliders with the possibility to include realistic cuts on the decay products. The method is based on an effective theory approach to…
The current searches for a heavy Higgs boson assume on-shell (stable) Higgs-boson production. The Higgs-boson production cross section is then sampled with a Breit-Wigner distribution (with fixed-width or running-width) and implemented in…