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Related papers: Results for all reactions e+ e- -> 4f, 4f + gamma …

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A Monte Carlo program is presented that computes all four fermion processes in $e^+ e^-$ annihilation. QED initial state corrections and QCD contributions are included. Fermions are taken to be massless, allowing a very fast evaluation of…

High Energy Physics - Phenomenology · Physics 2009-10-28 F. Berends , R , Kleiss , R. Pittau

We describe version 2.0 of the Fortran program GENTLE/4fan for the semi-analytic computation of cross-sections and distributions in four-fermion production in e+e- annihilation. GENTLE/4fan covers all charged current and neutral current…

High Energy Physics - Phenomenology · Physics 2009-10-30 D. Bardin , J. Biebel , D. Lehner , A. Leike , A. Olchevski , T. Riemann

Cross sections, angular distributions and forward-backward asymmetries are presented, of two-fermion events produced in e+e- collisions at centre-of-mass energies from 189 to 209 GeV at LEP, measured with the ALEPH detector. Results for…

High Energy Physics - Experiment · Physics 2012-08-27 The ALEPH Collaboration

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…

High Energy Physics - Phenomenology · Physics 2007-05-23 P. Christova , M. Jack , S. Riemann , T. Riemann

The various four-fermion production channels in $e^+ e^-$ annihilation are discussed and the {\tt CC11} process $e^+ e^- \rightarrow {\bar f}_1^u f_1^d f^u_2 {\bar f}_2^d$, {\mbox{$f$$\neq$$e$}}, is studied in detail. The cross section…

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

The production of a t\bar{t}-pair and its decay into a 6 fermion final state of different flavours in e+e- annihilation at centre of mass energies typical for linear colliders is analyzed in the framework of the Standard Model. The results…

High Energy Physics - Phenomenology · Physics 2011-09-13 Karol Kolodziej

The production of an intermediate-mass Higgs boson in processes of the kind $e^+ e^- \to 6$ fermions at the energies of future linear colliders is studied. The recently developed and fully automatic algorithm/code ALPHA is used to compute…

High Energy Physics - Phenomenology · Physics 2011-09-13 G. Montagna , M. Moretti , O. Nicrosini , F. Piccinini

The implementation of QED initial-state radiative corrections in the process of four-fermion production at LEP200 and higher-energy e+e- colliders is discussed. Because of the presence of charged-current processes, this is a nontrivial…

High Energy Physics - Phenomenology · Physics 2009-10-28 F. A. Berends , R. Pittau , R. Kleiss

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

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

Preliminary results on $e^+ e^- \to f \bar{f}$, $f=e, \mu, \tau, q$, including all LEP2 data are discussed. Good agreement is found with the Standard Model up to the highest energies. Limits on possible new physics are extracted.

High Energy Physics - Experiment · Physics 2007-05-23 G. Abbiendi

The rate for the production of a pair of massive fermions in $e^+ e^-$ annihilation plus real or virtual radiation of a pair of massless fermions is calculated analytically. The contributions for real and virtual radiation are displayed…

High Energy Physics - Phenomenology · Physics 2009-10-28 A. H. Hoang , J. H. Kühn , T. Teubner

I present a systematic study of all possible four leptons final states from $\gamma\gamma$ collisions. It is given a detailed account of fermion masses effects which are sizable since several collinear and $t$ channel enancements occur. The…

High Energy Physics - Phenomenology · Physics 2007-05-23 Mauro Moretti

We compute several total and differential cross sections relevant to top and WWZ physics at future $e^+e^-$ colliders taking into account the full set of Feynman diagrams for six fermion final states. We also include in our calculations…

High Energy Physics - Phenomenology · Physics 2009-10-30 Elena Accomando , Alessandro Ballestrero , Marco Pizzio

We discuss effects related to the fact that the final state particles of a reaction e+ e- -> t \bar{t} H are actually produced and they decay off mass shell. For the intermediate mass Higgs boson, which decays preferably into a…

High Energy Physics - Phenomenology · Physics 2008-11-26 Karol Kolodziej , Szymon Szczypinski

grc4f is a Monte-Carlo package for generating e+e- to 4-fermion processes in the standard model. All of the 76 LEP-2 allowed fermionic final state processes evaluated at tree level are included in version 1.0. grc4f addresses event…

High Energy Physics - Phenomenology · Physics 2015-06-25 J. Fujimoto , T. Ishikawa , T. Kaneko , K. Kato , S. Kawabata , Y. Kurihara , T. Munehisa , D. Perret-Gallix , Y. Shimizu , H. Tanaka

The relevance of radiative corrections to 4f production at LEP2 and future e+e- colliders is emphasized, and their treatment in the event generator RacoonWW is briefly discussed. In particular, the non-universal corrections are compared…

High Energy Physics - Phenomenology · Physics 2007-05-23 A. Denner , S. Dittmaier , M. Roth , D. Wackeroth

grc4f is a Monte-Carlo package for generating e+e- to 4-fermion processes in the standard model. All of the 76 LEP-2 allowed fermionic final state processes evaluated at tree level are included in version 1.1. grc4f addresses event…

High Energy Physics - Phenomenology · Physics 2009-10-28 J. Fujimoto , T. Ishikawa , T. Kaneko , K. Kato , S. Kawabata , Y. Kurihara , T. Munehisa , D. Perret-Gallix , Y. Shimizu , H. Tanaka

At future e+- e- linear colliders, the event rates and clean signals of scalar fermion production - in particular for the scalar leptons - allow very precise measurements of their masses and couplings and the determination of their quantum…

We investigated the effect of the light fermion masses on cross sections for e^+e^- into 4 fermions in the Fermion Loop scheme defined in hep-ph/9612260, and approximations to it. The effects are found to be very small, except of course in…

High Energy Physics - Phenomenology · Physics 2009-10-30 Jiri Hoogland , Geert Jan van Oldenborgh