Related papers: Light Fermion Mass Effects in e^+e^- -> 4 Fermions
We derive the low-energy electroweak effective lagrangian for the case of additional heavy, unmixed, sequential fermions. Present LEP1 data still allow for the presence of a new quark and/or lepton doublet with masses greater than $M_Z/2$,…
We propose a general classification of all four fermion final states in $\gamma\gamma$ collisions at a future $e^+e^-$ Linear Collider and discuss the relation of ``signal'' and ``background'' contributions in vector boson production. We…
Electrons interact strongly with their environment. The result of these interactions is, most of the time, encoded in an effective mass. In non-relativistic systems, as in condensed matter, the electrons plus interactions form a…
Assuming that the leptons and quarks other than top are massless at tree level, we show that their masses may be induced by loops involving the top quark. As a result, the generic features of the fermion mass spectrum arise from…
In view of the forthcoming experiments at high energy $e^+ e^-$ colliders, LEP2 and beyond, the process $e^+ e^- \to W^+ W^- \to 4f$ has been investigated for {\it off-shell} $W$'s. After deriving the matrix element for the process within…
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…
The boson and fermion particle masses are calculated in a finite quantum field theory. The field theory satisfies Poincar\'e invariance, unitarity and microscopic causality, and all loop graphs are finite to all orders of perturbation…
The recently completed 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…
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…
The mass of the W boson is determined from the direct reconstruction of its decays into purely hadronic and semi-leptonic events in e+e- collisions at LEP. The data sample corresponds to an integrated luminosity of 683 inverse picobarns…
Within the scenario of chiral freedom we compute the quark and lepton masses of the first two generations in terms of their chiral couplings. This allows us to make a rough estimate of the size of the chiral couplings, narrowing down the…
Large fermion mass effect on the Yukawa process $Z \ra b\bar{b}\ra b\bar{b} h (A)$ in the entire range of the neutral Higgs boson masses is found. It is particularly important for light Higgs bosons, which are still not excluded…
Advantages of the e-e- option at linear colliders for the study of supersymmetry are highlighted. The fermion number violating process $e^- e^- \to \selectron^- \selectron^-$ provides unique opportunities for studies of slepton masses and…
In $e^+ e^-$ collisions, electromagnetic effects caused by large charge density bunches modify the effective acceptance of the luminometer system of the experiments. These effects consequently bias the luminosity measurement from the rate…
We calculate total and differential cross sections for sfermion production in $e^+e^-$ annihilation and in photon-photon collisions with arbitrary photon polarization. The total cross section at a polarized photon collider is shown to be…
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…
The impact of higher-order final-state photonic corrections on the precise determination of the W-boson mass at the Tevatron and LHC colliders is evaluated. The W-mass shift from a fit to the transverse mass distribution is found to be…
We present new data on the mass of the light and strange quarks from SESAM/T$\chi$L. The results were obtained on lattice-volumes of $16^3\times 32$ and $24^3\times 40$ points, with the possibility to investigate finite-size effects. Since…
Using $e^+e^-$ collision data collected with the BESIII detector operating at the Beijing Electron Positron Collider, the cross section of $e^+e^-\to \pi^+\pi^- h_c$ is measured at 59 points with center-of-mass energy $\sqrt{s}$ ranging…
Properties of amplitudes that describe radiative corrections in a bag of heavy fermions bound by the Higgs boson exchange are studied. Classes of amplitudes, in which the large fermion mass is canceled out and hence produces no enhancement…