Freiburg 1998 – scientific programme

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T: Teilchenphysik

T 502: QCD V

T 502.6: Talk

Wednesday, March 25, 1998, 17:45–18:00, HS B

Massive Quark Production in Electron Positron Annihilation to Order α_s² — •T. Teubner⁴, K.G. Chetyrkin¹, A.H. Hoang², J.H. Kühn¹, and M. Steinhauser³ — ¹Inst. f. Theoret. Teilchenphysik, Univ. Karlsruhe, D-76128 Karlsruhe — ²Dep. of Physics, Univ. of California, San Diego, La Jolla, CA 92093-0319, USA — ³MPI f. Physik, Werner Heisenberg Inst., D-80805 Muenchen — ⁴DESY Theorie, D-22603 Hamburg

Recent analytical and numerical results for the three-loop polarization function allow to present a phenomenological analysis of the cross section for massive quark production in electron positron annihilation to order α_s². Numerical predictions based on fixed order perturbation theory are presented for charm and bottom production above 5 and 11.5 GeV, respectively. The contribution from these energy regions to α(M_Z²), the running QED coupling constant at scale M_Z, are given. The dominant terms close to threshold, i.e. in an expansion for small quark velocity β, are presented.