Related papers: S-matrix approach to the Z resonance
The prospects are presented for precise measurements of the branching ratios of the purely leptonic $B_c^+ \to \tau^+ \nu_\tau$ and $B^+ \to \tau^+ \nu_\tau$ decays at the Future Circular Collider (FCC). This work is focused on the hadronic…
Provided SUSY is realized in Nature, future colliders like the Large Hadron Collider (LHC) and a future e+e- linear collider (LC) will provide a wealth of data on SUSY phenomena. One important task will be to extract the Lagrangian…
Beamstrahlung is a dominant effect in the beam dynamics of the high luminosity next-generation lepton collider FCC-ee. We characterize the beamstrahlung radiation for the beam parameters at the four working energies, from the Z-pole to the…
We discuss the production, at high--energy e$^+$e$^-$ linear colliders, of new heavy fermions predicted by extensions of the Standard Model. We analyze in great details the various signals and the corresponding backgrounds for both pair…
Circular electron positron colliders, such as the CEPC and FCC-ee, have been proposed to measure Higgs boson properties precisely, test the Standard Model, search for physics beyond the Standard Model, and so on. One of the important goals…
Future linear colliders designs, ILC and CLIC, are expected to be powerful machines for the discovery of Physics Beyond the Standard Model and subsequent precision studies. However, due to the intense beams (high luminosity, high energy),…
In the context of future electroweak precision measurements at the Future Circular Lepton Collider (FCC-ee), we consider recent proposals aimed at finding signatures of physics beyond the Standard Model. In particular, we focus on recent…
Lepton flavor violation is one of the cleanest probes of physics beyond the standard model. In this work, we explore the sensitivity of the process $e^+ e^- \to \tau \mu$ to new physics above the TeV scale at the proposed circular…
Measurements of electroweak precision observables at future electron-positron colliders, such as the CEPC, FCC-ee, and ILC, will be sensitive to physics at multi-TeV scales. To achieve this sensitivity, precise predictions for the Standard…
Future linear $e^+e^-$ colliders aim for extremely high precision measurements. To achieve this, not only excellent detectors and well controlled machine conditions are needed, but also the best possible estimate of backgrounds. To avoid…
Boson-fermion pairing is considered in a discrete environment of bosons and fully spin-polarized fermions, coupled via an attractive Bose-Fermi Hubbard Hamiltonian in one dimension. The results of the T-matrix approximation for particles of…
Feshbach scattering resonances are being utilized in atomic gases to explore the entire crossover region from a Bose-Einstein Condensation (BEC) of composite bosons to a Bardeen-Cooper-Schrieffer (BCS) of Cooper pairs. Several theoretical…
We study possible new physics interactions in the $ZZH$ vertex contributing to the Higgsstrahlung process $e^+ e^- \to ZH$ at proposed future $e^+e^-$ colliders using the polarization of the $Z$ as a probe. We calculate the spin density…
We explore a scenario where Dark Matter (DM) couples to the Standard Model mainly via a scalar mediator ${\cal S}$ that is odd under a $Z_2$ symmetry, leading to interesting collider signatures. In fact, if linear interactions with the…
The search for a Z' is one of the tasks of future colliders. I study the capability to detect the Z' at a linear e+e- collider operating below resonance production. Depending on m_{\Zp} and the collider parameters we will be able to…
We describe how to probe new physics through examination of the form factors describing the Ztt couplings via the scattering process e^-e^+->t+tbar. We focus on experimental methods on how the top quark momentum can be determined and show…
The complete matrix elements for e^+ e^- -> 4f and e^+ e^- -> 4f + gamma are calculated in the Electroweak Standard Model for polarized massless fermions. The matrix elements for all final states are reduced to a few compact generic…
It has recently been shown that the studies of strongly-interacting electroweak symmetry breaking (EWSB) at photon colliders, via photon splitting into $W$ pair followed by longitudinal $W$-boson scattering, could be possible. Here we…
In this paper, a study is carried out on the $e^-p \to e^-\gamma^* p \to p W^+\gamma \nu_e$ production to probe quartic $W^+W^-\gamma\gamma$ couplings using 10, 100 ${\rm fb^{-1}}$ of $e^-p$ collisions data at $\sqrt{s}$= 1.30, 1.98 GeV at…
We explore the usefulness of very energetic linear $e^+e^-$ colliders in the $TeV$ range in studying an alternative scheme of electroweak symmetry breaking based on a strong interacting sector. The calculations are performed within the BESS…