1210.3594 (P. A. Baikov et al.)

R(s) and Z decay in order α_s^4: complete results    [PDF]

P. A. Baikov, K. G. Chetyrkin, J. H. Kühn, J. Rittinger

We report on our calculation of the order \alpha_s^4 axial singlet contributions for the decay rates of the Z-boson as well as the vector singlet contribution to the cross section for electron-positron annihilation into hadrons. Together with recently finished O(\alpha_s^4) calculations of the non-signlet corrections [1,2], the new results directly lead us to the first complete O(\alpha_s^4) predictions for the total hadronic decay rate of the Z-boson and the ratio R(s).

View original: http://arxiv.org/abs/1210.3594