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Related papers: On e+e- --> W+W- --> 4f(+gamma) at LEP2

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We accomplish our efforts to obtain predictions for all four-fermion final states of e+ e- annihilation and the corresponding bremsstrahlung reactions which are possible in the framework of the Standard Model. For this purpose we have…

High Energy Physics - Phenomenology · Physics 2011-09-13 F. Jegerlehner , K. Kolodziej

The process e^+e^- -> gamma gamma (gamma) is studied using data recorded with the OPAL detector at LEP. The data sample corresponds to a total integrated luminosity of 25.38 pb^{-1} taken at centre-of-mass energies of 130-172 GeV. The…

High Energy Physics - Experiment · Physics 2008-11-26 The OPAL Collaboration , K. Ackerstaff et al

The cross sections for the reaction $e^+ e^- \rightarrow l \bar l q \bar q $ and for similar four fermion production processes at LEP~1, LEP~2 and the NLC are calculated. Due to the extraordinary symmetry properties of the process, very…

High Energy Physics - Phenomenology · Physics 2009-10-28 Dima Bardin , Arnd Leike , Tord Riemann

The search for quartic anomalous gauge couplings at LEP requires appropriate predictions for the radiative processes e+ e- \to \nu\bar\nu \gamma\gamma, e+ e- \to q\bar{q}\gamma\gamma and e+ e- \to 4 fermions+\gamma. Matrix elements are…

High Energy Physics - Phenomenology · Physics 2009-11-07 G. Montagna , M. Moretti , O. Nicrosini , M. Osmo , F. Piccinini

The $e^+e^-\to\eta\gamma$ cross section has been measured in the center-of-mass energy range 1.07--2.00 GeV using the decay mode $\eta\to 3\pi^0$, $\pi^0\to \gamma\gamma$. The analysis is based on 36 pb$^{-1}$ of integrated luminosity…

The cross section of the $e^+e^-\to\omega\pi^0\to\pi^0\pi^0\gamma$ reaction was measured by the SND detector at VEPP-2M $e^+e^-$ collider in the energy range from threshold up to 1.4 GeV. Results of the cross section fitting by the sum of…

Formulae for the cross section of the process gamma gamma <-> e+ e- with all four particles polarized are obtained in the lowest order of the perturbation theory using REDUCE.

High Energy Physics - Phenomenology · Physics 2007-05-23 V. N. Baier , A. G. Grozin

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…

High Energy Physics - Phenomenology · Physics 2014-11-17 G. Couture , S. Godfrey

This note presents a combination of published and preliminary electroweak results from the four LEP collaborations and the SLD collaboration which were prepared for the 2004 summer conferences. [...] The main changes with respect to the…

We present a study of single-W production ($e^+e^-\to e^-\bar{\nu}_e W^+$) as a new probe of the anomalous couplings at the LEP energy region. We introduce simple cuts to separate the single-W process from W-pair production and have…

High Energy Physics - Phenomenology · Physics 2009-10-28 Toshio Tsukamoto , Yoshimasa Kurihara

We review the status of theoretical predictions for W-pair production at high energies. We discuss a systematic scenario towards a Monte-Carlo generator for e^+e^- --> 4f(\gamma), which meets the experimental requirements. In particular we…

High Energy Physics - Phenomenology · Physics 2007-05-23 W. Beenakker , A. Denner

The three different helicity states of W bosons produced in the reaction e+ e- -> W+ W- -> l nu q q~ at LEP are studied using leptonic and hadronic W decays. Data at centre-of-mass energies \sqrt s = 183-209 GeV are used to measure the…

High Energy Physics - Experiment · Physics 2012-08-27 L3 Collaboration

A test of the benchmark QED process e+e- -> gamma gamma (gamma) is reported, using the data collected with the DELPHI detector at LEP 2. The data analysed were recorded at centre-of-mass energies ranging from 161 GeV to 208 GeV and…

High Energy Physics - Experiment · Physics 2008-11-26 The DELPHI Collaboration , J. Abdallah

Full O(alpha) electroweak corrections for gamma-gamma-> W+W- are calculated including virtual corrections, soft and hard real photon and Z-boson emission. The corrections are quite large ranging from -2.5% at 500 GeV to -18% at 2 TeV,…

High Energy Physics - Phenomenology · Physics 2009-10-30 G. Jikia

The calculation of the full electroweak O(alpha) corrections to the charged-current four-fermion production processes e+e- --> nu_tau tau+ mu- anti-nu_mu, u anti-d mu- anti-nu_mu, and u anti-d s anti-c is briefly reviewed. The calculation…

High Energy Physics - Phenomenology · Physics 2008-11-26 A. Denner , S. Dittmaier , M. Roth , L. H. Wieders

The cross section of the process e+e- -> Ze+e is measured with 0.7fb^-1 of data collected with the L3 detector at LEP. Decays of the Z boson into quarks and muons are considered at centre-of-mass energies ranging from 183GeV up to 209GeV.…

High Energy Physics - Experiment · Physics 2012-08-27 L3 Collaboration

The process e+e- to gamma gamma (gamma) is studied using data recorded with the OPAL detector at LEP. The data sample corresponds to a total integrated luminosity of 56.2 pb-1 taken at a centre-of-mass energy of 183 GeV. The measured…

High Energy Physics - Experiment · Physics 2008-11-26 The OPAL Collaboration , K. Ackerstaff et al

We present a numerical estimate of the $\gamma^* \gamma^*$ total cross section at LEP and at the designed $e^+e^-$ Next Linear Collider (NLC), based upon the BFKL Pomeron. We find for the linear collider that the event rate is substantial…

High Energy Physics - Phenomenology · Physics 2009-10-28 J. Bartels , A. DeRoeck , H. Lotter

The $O(\alpha)$ corrections to $\gamma\gamma --> f \bar f$ in the Standard Model are calculated for arbitrary, light fermions $f$. The relevant analytical results are listed in a form that is appropriate for practical applications, and…

High Energy Physics - Phenomenology · Physics 2008-11-26 A. Denner , S. Dittmaier

Multipole analyses of the p(g,pi0), p(g,pi+) and p(g,g) reactions are carried out using different data sets. With sufficient constraints from polarization observables, the ratio of E2/M1 transition amplitudes for N->delta (EMR) appears to…

Nuclear Theory · Physics 2011-04-15 A. M. Sandorfi , S. Hoblit , J. Tonnison