New perturbation expansions in quantum chromodynamics and the determination of alpha(s)

0356868 - FZÚ 2011 RIV RO eng J - Článek v odborném periodiku
Caprini, I. - Fischer, Jan
New perturbation expansions in quantum chromodynamics and the determination of alpha(s).
Romanian Journal of Physics. Roč. 55, 5-6 (2010), s. 527-537. ISSN 1221-146X. E-ISSN 1221-146X
Grant CEP: GA MŠMT LC527; GA MŠMT LA08015
Výzkumný záměr: CEZ:AV0Z10100502
Klíčová slova: quantum chromodynamics * conformal mapping * tau lepton decay
Kód oboru RIV: BF - Elementární částice a fyzika vys. energií
Impakt faktor: 0.340, rok: 2010

We consider a new class of perturbation expansions which in a systematic way incorporate the available information about the divergent character of the perturbation series in QCD. The new expansion functions, which replace the powers of the coupling, are defined by the analytic continuation in the Borel plane, achieved through an optimal conformal mapping. We consider several possibilities of implementing the known behaviour of the Borel transform, which have the same convergence rate, but differ at low orders. The new expansions allow a precise determination of the strong coupling $/alpha_s$ from the hadronic decays of the tau lepton.
Trvalý link: http://hdl.handle.net/11104/0195277