The Effective Fine Structure Constant at TESLA Energies
| dc.creator | Jegerlehner, F. | |
| dc.date | 2001-05-27 | |
| dc.date.accessioned | 2026-07-07T03:44:36Z | |
| dc.date.available | 2026-07-07T03:44:36Z | |
| dc.description | We present a new estimate of the hadronic contribution to the shift in the fine structure constant at LEP and TESLA energies and calculate the effective fine structure constant. Substantial progress in a precise determination of this important parameter is a consequence of substantially improved total cross section measurements by the BES II collaboration and an improved theoretical understanding. In the standard approach which relies to a large extend on experimental data we find $Δ\al_{\rm hadrons}^{(5)}(\mz) = 0.027896 \pm 0.000395$ which yields $α^{-1}(\mz) = 128.907 \pm 0.054$. Another approach, using the Adler function as a tool to compare theory and experiment, allows us to to extend the applicability of perturbative QCD in a controlled manner. The result in this case reads $Δα^{(5)}_{\rm had}(M_Z^2) = 0.027730 \pm 0.000209$ and hence $α^{-1}(\mz) = 128.930 \pm 0.029$. At TESLA energies a new problem shows up with the definition of an effective charge. A possible solution of the problem is presented. Prospects for further progress in a precise determination of the effective fine structure constant are discussed. | |
| dc.description | 21 pages 6 figures 2 tables | |
| dc.identifier | https://arxiv.org/abs/hep-ph/0105283 | |
| dc.identifier | http://arxiv.org/abs/hep-ph/0105283 | |
| dc.identifier.uri | http://salesiana.dossiersoluciones.com/handle/123456789/40629 | |
| dc.subject | High Energy Physics - Phenomenology | |
| dc.title | The Effective Fine Structure Constant at TESLA Energies | |
| dc.type | text |