Related papers: Contact Interactions: Results from ZEUS and a Glob…
A combined analysis of the data on Bhabha scattering at centre-of-mass energies 183 and 189 GeV from the LEP experiments ALEPH, L3 and OPAL is performed to search for effects of TeV strings in quantum gravity models with large extra…
We have directly measured the ZZ-gamma and Z-gamma-gamma couplings by studying p pbar --> l+ l- gamma + X, (l = e, mu) events at the CM energy of 1.8$ TeV with the D0 detector at the Fermilab Tevatron Collider. A fit to the transverse…
A search for scalar and vector leptoquarks coupling to first generation fermions is performed in the H1 experiment at the ep collider HERA. The analysis uses e^- p data collected in 1998 and 1999 at a centre-of-mass energy of 320 GeV,…
The measurements of the QED reaction $ \EEGG $ performed with the L3 detector are used to search for new physics phenomena beyond the Standard Model. No evidence for these phenomena is found and new limits on their parameters are set. First…
Limits are set on the pair production of scalar leptoquarks, where all possible decays of the leptoquark into a quark ($t$, $b$) and a lepton ($\tau$, $\nu$) of the third generation are considered. The limits are presented as a function of…
A search is conducted for new resonant and non-resonant high-mass phenomena in dielectron and dimuon final states. The search uses 36.1 fb$^{-1}$ of proton-proton collision data, collected at $\sqrt{s}$ = 13 TeV by the ATLAS experiment at…
The four fermion contact interactions, required to explain the anomalous HERA result, could come from the exchange of new heavy (probably composite) resonances. Depending on their charges and quantum numbers, one gets different scenarios…
The analysis of events with isolated leptons and missing transverse momentum in the H1 experiment is discussed for the electron, muon and tau channels. In the Standard Model (SM) framework, production of real W-bosons gives rise to such…
A search for charged-lepton-flavour violating $\mu\tau qt$ ($q=u,c$) interactions is presented, considering both top-quark production and decay. The data analysed correspond to 140 $\textrm{fb}^{-1}$ of proton-proton collisions at a…
Neutral and charged current deep inelastic ep scattering with longitudinally polarised lepton beams has been studied with the H1 and ZEUS detectors at HERA. The differential cross sections were measured in the range of four-momentum…
Results are presented for a test of the compositeness of the heaviest charged lepton, $\tau$, using data collected by the CMS experiment in proton-proton collisions at a center-of-mass energy of 13 TeV at the CERN LHC. The data were…
Forces beyond those of the standard model may manifest themselves at low energies as four-fermion contact interactions. If these new forces are independent of colour and flavour quantum numbers including baryon and lepton number, then all…
Three searches are presented for signatures of physics beyond the standard model (SM) in $\tau\tau$ final states in proton-proton collisions at the LHC, using a data sample collected with the CMS detector at $\sqrt{s}$ = 13 TeV,…
We examine the phenomenological implications of a 200 GeV leptoquark in light of the recent excess of events at HERA. Given the relative predictions of events rates in e^+p versus e^-p, we demonstrate that classes of leptoquarks may be…
In 1999 the CERES/NA45 ran at the CERN SPS with a beam energy of 40 GeV/nucleon. The data set comprises about 8.7 millions Pb-Au events with a trigger selection corresponding to approximately the most central 30% of the geometrical cross…
We make a Monte Carlo study on compositeness of first generation quarks and leptons using the Drell-Yan distribution in the high dielectron mass region at the Tevatron and LHC energies. The current experimental lower limits on the…
An analysis is presented of events containing jets including at least one $b$-tagged jet, sizeable missing transverse momentum, and at least two leptons including a pair of the same electric charge, with the scalar sum of the jet and lepton…
A search for supersymmetry in events with four or more charged leptons (electrons, muons and $\tau$-leptons) is presented. The analysis uses a data sample corresponding to $139\,\mbox{fb\(^{-1}\)}$ of proton-proton collisions delivered by…
Various searches for leptoquarks, scalar quarks in $R_p$-violating supersymmetric models, and excited fermions performed by the HERA experiments H1 and ZEUS are reviewed. No evidence for new particle production was observed from data…
Neutrino-electron scattering is a purely leptonic fundamental interaction and therefore provides an important channel to test the Standard Model, especially at the low energy-momentum transfer regime. We derived constraints on neutrino…