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Predictions of ZFITTER v.6 for fermion-pair production with acollinearity cut

P. Christova·M. Jack·S. Riemann·T. Riemann
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Abstract

ZFITTER is a Fortran package for the description of fermion-pair production in e+e- annihilation. We report on results of a rederivation of the complete set of analytical O(alpha) formulae for the treatment of photonic corrections to the total cross-section and the integrated forward-backward asymmetry with combined cuts on acollinearity angle, acceptance angle, and minimal energy of the fermions. Numerically, the following changes result in ZFITTER v. 6.11 compared to ZFITTER v. 5.20/21: (i) at the Z resonance -- numerical changes are negligible; (ii) at LEP 1 energies off-resonance -- corrections amount to at most few per mil; (iii) at LEP 2 energies -- corrections amount to one per cent or less. Thus, the predictions for LEP/SLC data remain unchanged within the actual errors.

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P. Christova, M. Jack, S. Riemann, T. Riemann. 1999-08-06. Predictions of ZFITTER v.6 for fermion-pair production with acollinearity cut. https://arxiv.org/abs/hep-ph/9908289

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