Related papers: Beam Blow Up due to Beamstrahlung in Circular $e^+…
For future precision analyses of the Higgs boson at $\approx 125$ GeV, $h_{125}$, a precise knowledge of its production and decay properties is mandatory. While in the Standard Model (SM) these calculations are quite advanced, in many…
A $\gamma\gamma$ collider, either in conjunction with an $e^+e^-$ linear collider or as a stand-alone facility, offers a very attractive Higgs physics programme at relatively low centre-of-mass (c.m.) energies. While the Higgs boson that…
We investigate the possibility of probing an extra Higgs boson at future linear $e^+ e^-$ colliders. We consider the production process $e^+e^- \to H\nu \bar\nu$, followed by the decay $H \to W^+W^-$, where $H$ is the extra…
Exploiting the fact that $W$ pair production in high-energy $\gamma \gamma$ collisions is very large, we use this process to trigger Higgs, $Z$ or photon radiation. We find that there are sizeable rising cross-sections for triple bosons…
We study the effect of interference between the Standard Model Higgs boson resonance and the continuum background in the process gamma gamma -> H -> b b-bar at a photon collider. Taking into account virtual gluon exchange between the…
We study the prospects of the B-L model with an additional $Z'$ boson to be a Higgs boson factory at high-energy and high-luminosity linear electron positron colliders, such as the ILC and CLIC, through the Higgs-strahlung process…
A new effect is presented, which changes the emittance during colliding-beam operation in circular colliders. If the initial transverse distribution is Gaussian, the collision probability is much higher for particles in the core of the beam…
A future 100 TeV pp collider will explore energies much higher than the scale of electroweak (EW) symmetry breaking. In this paper we study some of the phenomenological consequences of this fact, concentrating on enhanced bremsstrahlung of…
Higgs bosons can have a substantial ``invisible'' branching ratio in many extensions of the Standard Model, such as models where the Higgs bosons decay predominantly into light or massless weakly interacting Goldstone bosons. In this work,…
In the colliders, the macroscopically large impact parameters give a substantial contribution to the standard cross section of the $e^+ e^- \to e^+ e^- \gamma$ process. These impact parameters may be much larger than the transverse sizes of…
The discovery of the Higgs particle at 125 GeV is demanding a detailed knowledge of the properties of this fundamental component of the Standard Model. To that aim various proposals of electron and muon colliders have been put forward for…
A semi-analytical model has been developed to study a combined effect of Beamstrahlung due to beam-beam interaction and beam coupling impedance in the future lepton colliders CEPC and FCCee. This model allows evaluating an impact of the…
In gauge models with bigger number of Higgs particles their couplings to fermions are more complicated then in the standard model (SM). The influence of the Higgs bosons exchange on the neutrino production cross section in $e^-e^+$…
One-loop production of a Higgs boson in electro-photon collisions at future accelerators is studied via the process (e gamma -> e H), for intermediate Higgs masses. Exact cross sections, including the possibility of longitudinally polarized…
We evaluate the prospects for measuring $BR(h\to\gamma\gamma)$ for a Standard-Model-like Higgs boson at the Next Linear $e^+e^-$ Collider in the $e^+e^-\to Z^*\to Z h$ and $e^+e^-\to\nu_e\anti\nu_e h$ production modes. Relative merits of…
Standard Model Higgs pair production at e^+e^- colliders has the capability to determine the Higgs boson self-coupling \lambda. I present a detailed analysis of the e^+e^- -> ZHH and e^+e^- -> \nu\bar\nu HH signal channels, and the relevant…
We explore the collider relevance of a charge-radius coupling among light mesons in composite Higgs models. In particular, we focus of a coupling of the photon to the composite Higgs and a composite singlet, arising from isospin violation…
We review the decay properties and production mechanisms of the Standard-Model Higgs boson at a future e^+e^- linear collider with special emphasis on the influence of quantum corrections. We also discuss how its quantum numbers and…
We study angular observables in the $e^+e^-\to Z H\to \ell^+ \ell^-\,b\bar{b}$ channel at future circular $e^+ e^-$ colliders such as CEPC and FCC-ee. Taking into account the impact of realistic cut acceptance and detector effects, we…
We update our previous calculation of di--jet production in two--photon collisions at future \ee\ colliders, including both beam-- and bremsstrahlung. We then discuss the production of heavy ($c,b,t$) quarks. Our study re--confirms that…