Related papers: Standard Model at LEPII
Electroweak processes with four fermions in the final state were measured extensively at LEP-2 in e+e- collisions with centre-of-mass energies up to 209 GeV. By combining the results obtained by Aleph, Delphi, L3 and Opal, the predictions…
This paper summarises the search for the Standard Model Higgs boson in e+e- collisions at centre-of-mass energies up to 209 GeV performed by the OPAL Collaboration at LEP. The consistency of the data with the background hypothesis and…
Neutral-current four-fermion production, e+e- -> ffff is studied in 0.7/fb of data collected with the L3 detector at LEP at centre-of-mass energies root(s)=183-209GeV. Four final states are considered: qqvv, qqll, llll and llvv, where l…
The process e+e- -> gamma gamma (gamma) is studied using data collected by the OPAL detector at LEP between the years 1997 and 2000. The data set corresponds to an integrated luminosity of 672.3pb-1 at centre-of-mass energies lying between…
Recent theories propose that quantum gravity effects may be observable at LEP energies via gravitons that couple to Standard Model particles and propagate into extra spatial dimensions. The associated production of a graviton and a photon…
The total and differential cross sections of the process e+e- -> n gamma with n >= 2 are measured using data collected by the L3 experiment at centre-of-mass energies of \sqrt{s}=183 and 189 GeV. The results are in agreement with the…
This paper describes a search for the Standard Model Higgs boson using data from e^+e^- collisions collected at center-of-mass energies of 161, 170 and 172 GeV by the OPAL detector at LEP. The data collected at these energies correspond to…
The cross section for the production of Z boson pairs is measured using the data collected by the L3 detector at LEP in 1999 in e^+e^- collisions at centre-of-mass energies ranging from 192 GeV up to 202 GeV. Events in all the visible final…
All couplings of a new heavy gauge boson to ordinary fermions can be determined in a model-independent way at a large $e^+e^-$ collider for large enough statistics. No such determination is possible at LEP 200, however, because its design…
The past ten years of physics with e+e- colliding experiments at LEP and SLAC have shown the success of these experiments on not only impressively proving the theoretical predictions of the Standard Model (SM), but also to help provide…
The pair production of Z bosons is studied using the data collected by the L3 detector at LEP in 1998 in e+e- collisions at a centre-of-mass energy of 189 GeV. All the visible final states are considered and the cross section of this…
In its second phase, LEP has given the unique opportunity to study four fermion processes never observed before. This papers deals with a preliminary study of $WW$, $We\nu$, $ZZ$ and $Z\gamma^\star$ production in $e^+e^-$ collisions.…
The process e+e- to 2 (or 3) gammas is studied using data recorded with the OPAL detector at LEP. The data sample taken at a centre-of-mass energy of 189 GeV corresponds to a total integrated luminosity of 178 pb-1. The measured…
In this paper we compare $H^+H^-$ and $W^+W^-$ into four-fermion production at centre-of-mass energies typical of LEP2 and somewhat larger. The theoretical framework considered is the Minimal Supersymmetric Standard Model. The interest in…
Strange baryon pair production in two-photon collisions is studied with the L3 detector at LEP. The analysis is based on data collected at e+e- centre-of-mass energies from 91 GeV to 208 GeV, corresponding to an integrated luminosity of 844…
This note presents a combination of published and preliminary electroweak results from the four LEP collaborations ALEPH, DELPHI, L3 and OPAL based on electron-positron collision data taken at centre-of-mass energies above the Z-pole, $130…
A complete set of postulates of the standard model of the electroweak interaction and mass generation is formulated and confirmed deriving the Lagrangian for the standard model. A massive fermion is formed by a right-handed and a…
Precise measurements of electroweak processes at the International Linear Collider (ILC) will provide unique opportunities to explore new physics beyond the Standard Model. Fermion pair productions are sensitive to a new contact interaction…
An S-Matrix ansatz is used to determine the mass and width of the Z boson, as well as the contributions of gamma/Z interference and Z boson exchange to fermion-pair production. For this purpose we use hadron and lepton-pair production cross…
W+W-gamma production at LEP2 is studied using data collected with the DELPHI detector at centre-of-mass energies between 189 GeV and 209 GeV, corresponding to an integrated luminosity of about 600 pb^-1. Cross-sections are measured for the…