Related papers: Unambiguously Testing Positivity at Lepton Collide…
We study the discovery prospects of the leptophilic photon Z\_l, a hypothetical gauge boson beyond the Standard Model, at future electron-positron colliders. Our analysis is based on the process e+e- -> mu+mu- and consistently includes…
The exclusive two-photon production at the LHC of pairs of W and Z bosons provides a novel and unique test-ground for the electroweak gauge boson sector. In particular it offers, thanks to high gamma-gamma center-of-mass energies, large and…
Whether in nature exists Majorana neutrino is one of the most fundamental questions in physics. It is directly related to the violation of accidental $U(1)$-lepton number symmetry(LNV). Enormous efforts had been put into such test and among…
Unitarity, a powerful constraint on new physics, has not always been properly accounted for in the context of hidden sectors. Feng, Rajaraman and Tu have suggested that large (pb to nb) multi-photon or multi-lepton sugnals could be…
Inspired by Schwartz, Jang-Lewis and Victory, who study in particular generalizations of triangularizations of matrices to operators, we shall give for positive operators on Lebesgue spaces equivalent definitions of atoms (maximal…
In the attempt to fully profile a $Z'$ boson accessible at the Large Hadron Collider (LHC), we study the sensitivity of di-lepton (for the electron, muon and tauon cases) and di-quark (for the case of the heavy flavours, $t$ and, possibly,…
The gravitational positivity bound gives quantitative "swampland'' constraints on low-energy effective theories inside theories of quantum gravity. We give a comprehensive discussion of this bound for those interested in applications to…
We examine very general four-point interactions arising from new physics and contributing to the Higgs production process e+e- -> HZ. We write all possible forms for these interactions consistent with Lorentz invariance. We allow the…
We establish model independent bounds on the anomalous magnetic and electric dipole moments of the tau-lepton using the two-photon processes $\gamma\gamma \to \tau^+\tau^-$ and $\gamma\gamma \to \tau^+\tau^-\gamma$. We use ${\cal L}=10, 50,…
We investigate the sensitivities on the Wilson coefficients of dimension-six operators associated with the anomalous $H\gamma\gamma$, $H\gamma Z$ and $HZZ$ vertices through the process $\mu^- \mu^+ \rightarrow Z\gamma\gamma$ at future muon…
Effects of Kaluza-Klein excited neutral vector bosons ($Z'$ bosons) in the gauge-Higgs unification on $e^+e^- \to \bar{q}q, \ell^+\ell^-$ cross sections are studied, particularly in future $e^+ e^-$ collider experiments with polarized…
In this study, we explore the non-standard $\nu\bar{\nu}\gamma \gamma$ couplings parametrized by dimension-seven operators via $e^{+}e^{-} \to \nu\bar{\nu}\gamma$ process at the FCC-ee/CEPC and $\mu^{+}\mu^{-}\to\nu\bar{\nu}\gamma$ process…
Theories such as massive Galileons and massive gravity can satisfy the presently known improved positivity bounds provided they are weakly coupled. We discuss the form of the EFT Lagrangian for a weakly coupled UV completion of massive…
We show how the processes $e^- e^+ \to ZH, ~ \gamma H$, which will be studied at LEP2 and at high energy colliders, could be used to search for types of New Physics (NP) characterized by an effective NP scale in the few TeV range and…
A detailed analysis of ZZ production at the upgraded Fermilab Tevatron and the CERN Large Hadron Collider is presented for general ZZZ and ZZ\gamma couplings. Deviations from the Standard Model gauge theory structure for each of these can…
We examine the possibility to detect new SM-neutral vector bosons ($Z'$) that couple exclusively to leptons in the electron-positron mode of the Future Circular Collider (FCC-ee). Focusing on the $Z'$ production with a radiated photon…
Generation dependent discrete symmetries often appear in models derived from superstring theories. In particular, in the framework of E$_6$ models the presence of such symmetries is required in order to allow for the radiative generation of…
Gravity can become strong at the TeV scale in the theory of extra dimensions. An effective Lagrangian can be used to describe the gravitational interactions below a cut-off scale. In this work, we study the diphoton production in…
This is a short review of present and future limits on new neutral gauge bosons, in particular on hadrophilic or leptophobic $Z'$s recently proposed to interpret the observed fluctuations of $\Gamma _{c,b}$ at LEP. Light gauge bosons…
The main possibilities of investigation of leptons and bosons birth in interaction of polarized photons are considered. The usage of $\gamma \gamma \to f \bar{f} [+\gamma]$ reactions for the luminosity measurement on linear photon collider…