Related papers: Lepton Spectra from e^+ e^- \to W^+ W^- in the BES…
A data sample corresponding to an integrated luminosity of 232pb^-1 was collected in 1997 and 1998 by the L3 experiment at LEP in e+e- collisions at centre-of-mass energies between 181.7GeV and 188.7GeV. Pair production of fermions and…
Searches for first generation scalar and vector leptoquarks, and for squarks in R-parity violating SUSY models with the direct decay of the squark into Standard Model particles, have been performed using e+e- collisions collected with the…
A selection of di-lepton events with significant missing transverse momentum has been performed using a total data sample of 77.0 pb-1 at e+e- centre-of-mass energies of 161 GeV, 172 GeV and 183 GeV. The observed numbers of events: four at…
We investigate the possibility of probing the triplet Higgs boson sector via single charged Higgs production in the process $e^+ e^- \to H^+ l \nu_l$, at high energy electron-positron colliders, using the tree level $H^+W^-Z$ coupling which…
We study the lepton-flavor-violating reaction $\mu^+ e^- \to e^+ e^-$ within two extensions of the standard model that include heavy neutrinos. The reaction is studied in the low energy limit in the form of muonium decay $M\to e^+ e^-$ and…
New heavy charged lepton production and decay signatures at future electron-positron colliders are investigated at $\sqrt {s}=500$ GeV. The consequences of model dependence for vector singlets and vector doublets are studied. Distributions…
Events containing a pair of charged leptons and significant missing transverse momentum are selected from a data sample corresponding to a total integrated luminosity of 20.6 pb^-1 at centre-of-mass energies of 161 GeV and 172 GeV. The…
We carry out a study of intermediate-mass (between 1 and 2.5 GeV) dilepton spectra from hadronic interactions in heavy-ion collisions. The processes considered are $\pi\pi\to l{\bar l}$, $\pi\rho\to l{\bar l}$, $\pi a_1\to l{\bar l}$,…
We search for lepton flavour violating events (e mu, e tau and mu tau) that could be directly produced in e+e- annihilations, using the full available data sample collected with the OPAL detector at centre-of-mass energies between 189 GeV…
Hadron production and lepton-pair production in e+e- collisions are studied with data collected with the L3 detector at LEP at centre-of-mass energies sqrt{s}=192-208GeV. Using a total integrated luminosity of 453/pb, 36057 hadronic events…
Lepton flavor violating interactions are absent in the standard model but are expected in various beyond standard models. In this work, the potential of the future circular electron-positron collider to probe the four fermion lepton flavor…
We present a measurement of the coefficient alpha_2 of the leptonic polar-angle distribution from W boson decays, as a function of the W transverse momentum. The measurement uses an 80+/-4 pb^{-1} sample of proton-antiproton collisions at…
We study the Higgs pair-production in the Standard Model of the strong and electroweak interactions at future $e^{+}e^{-}$ collider energies, with the reaction $e^{+}e^{-}\to t \bar t HH$. We evaluated the total cross section of $t\bar tHH$…
LHCb data indicate a significant difference in widths between the B->K (or K^*) + e^+ e^- and B->K (or K^*) + {\mu}^+ {\mu}^- decays (April 2017). The width of the e^+ e^--channel is noticeably larger than that of the {\mu}^+…
The precision measurements of lepton electroweak parameters at SLD and LEP are reviewed and discussed. The updated SLD weak mixing angle measurement from $A_{LR}$ and the lepton left-right forward-backward asymmetries is…
Production of electroweak bosons in e+e- annihilation into quarks and into leptons at energies much greater than 100 Gev is considered. We account for double-logarithmic contributions to all orders in electroweak couplings. It is assumed…
Excited leptons are searched for using the L3 detector at LEP. The data collected at centre-of-mass energies in the range from 192 up to 202 GeV correspond to a total luminosity of 233 pb^(-1). No evidence of either pair production of…
We begin to analyze and contrast the predictions for the decay $b\to s\ell^+\ell^-$ in the Left-Right Symmetric Model(LRM) with those of the Standard Model(SM). In particular, we show that the forward-backward asymmetry of the lepton…
The e^+ jet invariant mass spectrum produced in the reaction e^+ p -> e^+ X has been studied at a center-of-mass energy of 300 GeV. The data were collected using the ZEUS detector operating at the HERA collider, and correspond to an…
Inspired by precision tests of the Standard Model in future lepton colliders, the numerical analysis of the following scattering processes, $e^+e^- \rightarrow Z h^0\gamma$ and $e^+e^- \rightarrow Z H^0 \gamma$, are carried at the tree…