Related papers: No-scale supergravity confronts LEP diphoton event…
We perform a detailed study of the process $e^+e^-\to\gamma\nu_l\bar\nu_l$ and its sensitivity to anomalous gauge boson couplings of the $\gamma WW$ vertex. We concentrate on LEP II energies, $\sqrt{s}=200$ GeV, and energies appropria- te…
A phenomenological extension of the well-known brane-world cosmology of Dvali, Gabadadze and Porrati (eDGP) has recently been proposed. In this model, a cosmological-constant-like term is explicitly present as a non-vanishing tension sigma…
In some supersymmetric models, the gluino is predicted to be light and stable. In that case, it would hadronize to form R-hadrons. In these models, the missing energy signature of the lightest supersymmetric particle is no longer valid,…
We explore the collider prospects of neutrino non-standard interaction with a Standard Model (SM) gauge-singlet leptonic scalar $\phi$ carrying two units of lepton-number-charge. These leptonic scalars are forbidden from interacting with…
The CDF and D0 collaborations have both reported unusual events in the dilepton+jets sample with very high lepton and missing transverse energies. It is possible, but very unlikely, that these events originate from top quark pair…
In 2018, the CMS collaboration reported a di-photon excess around 95.3 GeV with a local significance of 2.8 $\sigma$. Interestingly, the CMS collaboration also reported a di-tau excess recently at 95 $\sim$ 100 GeV with a local significance…
The production of invisible pairs of lightest neutralinos accompanied by a large-angle hard photon in the reaction $e^+ e^- \to \chi^0_1 \chi^0_1 \gamma$ is studied at LEP2 energies. The most general gaugino/higgsino composition of the…
In this note we assess the validity and uncertainties in the predictions of the eikonalised mini-jet model for $\sigma^{inel}_{\gamma \gamma}$. We are able to find a choice of parameters where the predictions are compatible with the current…
We present a detailed description of a search for anomalous production of missing E_T ($\mett$), jets, leptons ($e, \mu, \tau$), b-quarks, or additional photons in events containing two isolated, central ($|\eta|<1.0$) photons with $\Et >…
In the context of a nonuniversal and anomaly free $U(1)_{X}$ extension of the standard model, we examine the decay of a $750$GeV scalar singlet state, $\xi_{\chi}$, as a possible explanation of the observed diphoton excess announced by the…
Extrapolations of soft scalar mass parameters in supersymmetric theories can be used to explore elements of the physics scenario near the grand unification scale. We investigate the potential of this method in the lepton sector of SO(10)…
This article presents recent results of searches for physics beyond the Standard Model using the CDF and the D$\not$O detector at the Fermilab Tevatron Collider. All results shown correspond to analysis performed using the past 1992-1996…
The first data from the LHC Run-2 have shown a possible excess in diphoton events with invariant mass $\sim 750$ GeV, suggesting the existence of a new resonance which may decay dominantly into dark matter (DM) particles. We show in a…
We introduce a new N=1 no-scale supergravity model with F- and D-term breaking. It contains a single chiral supermultiplet T and a single U(1) vector multiplet U, gauging an axionic shift symmetry. Both supersymmetry and the gauge symmetry…
In a large class of scalar-tensor theories that are potential candidates for dark energy, a nonminimal coupling between the scalar and the photon is possible. The presence of such an interaction grants us the exciting prospect of directly…
As an interpretation of the 750 GeV diphoton excesses recently reported by both ATLAS and CMS collaborations, we consider a simple extension of the Standard Model with a Dirac fermion dark matter where a singlet complex scalar field…
We show that the present LEPI lower bound on the Standard Model Higgs boson mass ($M_H\gsim60\GeV$) applies as well to the lightest Higgs boson ($h$) of the minimal $SU(5)$ and no-scale flipped $SU(5)$ supergravity models. This result would…
The search for new physics in single- and multi-photon final states with large missing energy at LEP and future e^+ e^- colliders requires precise predictions for the Standard Model irreducible background. While at LEP1 the theoretical…
Data taken by the DELPHI experiment at centre-of-mass energies of 183 GeV and 189 GeV with a total integrated luminosity of 212 pb^{-1} have been used to search for the supersymmetric partners of the electrons, muons, and taus in the…
The ATLAS and CMS experiments at the LHC have reported an excess of diphoton events with invariant mass around 750 GeV, with local significance of about $3.6 \sigma$ and $2.6 \sigma$, respectively. We entertain the possibility that this…