arXiv subjects

Jochen Biebel

Publications and source records attributed to Jochen Biebel.

5 recordsLinked to original sources

arXiv1999

Off-shell W pair production with anomalous couplings: The CC11 process

The differential cross-sections for processes of the type e+ e- to W+ W- to l nu q anti-q are determined with account of background contributions and of anomalous triple gauge boson couplings. Analytic expressions for dsigma/ds1 ds2 dcostheta, where theta is the production angle of the W boson, are numerically integrated with the Fortran package GENTLE. QED corrections are taken into account in the leading logarithmic approximation. The importance of the various contributions is studied for center-of-mass energies of 190 GeV, 500 GeV, and 1 TeV.

hep-ph↗

arXiv1998

Seeking CP Violating Couplings in ZZ Production at LEP2

The effects of CP violating anomalous ZZZ and gammaZZ vertices in ZZ production are determined. We present the differential cross-section for e+e- -> ZZ with dependence on the spins of the Z bosons. It is shown that from the different spin combinations those with one longitudinally and one transversally polarized Z in the final state are the most sensitive to CP violating anomalous couplings.

hep-ph↗

arXiv1998

Anomalous Couplings in W Pair Production

I present a short overview over W pair production and studies of angular differential cross-sections with and without initial state radiation applying semi-analytical methods and using the Fortran program GENTLE. The influence of anomalous couplings to this process is also discussed.

hep-ph↗

arXiv1997

Four-Fermion Production with Anomalous Couplings at LEP2 and NLC

I give a short report on the semi-analytical approach to off-shell W pair production. In particular, I show the effects of irreducible background diagrams of the CC11 class in the differential cross-section. Further, I study the influence of potential anomalous couplings at a future linear collider and investigate the sensitivity of the forward-backward asymmetry to anomalous couplings.

hep-ph↗

arXiv1996

Predictions for Anomalous tau+ tau- gamma Production at LEP 1

We calculate distributions for tau+ tau- gamma production at LEP 1 taking into account a potentially existing anomalous magnetic moment a_tau of the tau lepton. The existing upper limits for |a_tau| are known from the dependence of the decay Z -> tau+ tau- gamma on (a_tau)^2 and are of the order of (1 - 5)%. We show that such limits are also sensitive to linear terms in a_tau, which are of equal importance at |a_tau| ~ (1 - 2)% and dominate below this value. Contributions from an electric dipole moment d_tau do not interfere with the electromagnetic vertex or with the anomalous magnetic moment. Appropriate formulae are derived.

hep-ph↗