Forward-backward asymmetry with Z' effects in the process e+e-to mu+mu-

The forward - backward asymmetry with Z ′ effects in the process e + e − → μ + μ −

Having taken the QED radiative correction and one-loop weak corrections into account, we have computed the unpolarized forward-backward asymmetry in the process e+e−− > μ+μ− at a very reasonable accuracy. Special attention to the effects around the LEP 200 energy, induced by the possible Z ′ boson of the left-right symmetric model SU(2)L×SU(2)R×U(1)B−L, is paid. The numerical results of the dir...

The Forward–backward Asymmetry in Nnlo Qcd

We have recently calculated the second-order QCD corrections to the forward–backward asymmetry in ee annihilation. Here we recall the results and compare them to others in the literature. RAL–TR–1999–048 CERN–TH/99–204 July 1999 Talk given by M. Seymour at 13th Rencontres de Physique de la Vallée d’Aoste, Results and Perspectives in Particle Physics, La Thuile, Aosta Valley, Italy, February 28t...

QED Radiative Corrections to Z Boson Production and the Forward Backward Asymmetry at Hadron Colliders

The O(α) radiative corrections to the process p p (−) → γ∗, Z → `+`− (` = e, μ) are calculated. Factorizing the collinear singularity associated with initial state photon bremsstrahlung into the parton distribution functions, we find that initial state corrections have a much smaller effect than final state radiative corrections. Due to mass singular logarithmic terms associated with photons em...

The forward-backward asymmetry at NNLO revisited

I reconsider the forward-backward asymmetry for flavoured quarks in electron-positron annihilation. I suggest an infrared-safe definition of this observable, such that the asymmetry may be computed in perturbative QCD with massless quarks. With this definition, the first and second order QCD corrections are computed.

Forward - backward and isospin asymmetry for B →