2005/05/14 by G. Abbiendi, Abbiendi, G.
Physics and Astronomy · #FOS: Physical sciences #High Energy Physics - Experiment (hep-ex) #High-Energy Particle Collisions Research #Particle physics theoretical and experimental studies #Quantum Chromodynamics and Particle Interactions #hep-ex
paper · pdf · doi:10.48550/arxiv.hep-ex/0505040
Talks given at the 19th Rencontres De Physique De La Vallee D'Aoste (27.2-5.3.05), La Thuile, Italy and at the 40th Rencontres De Moriond On Electroweak Interactions And Unified Theories (5.3-12.3.05), La Thuile, Italy. Added 1 figure and related text wrt vers.1
openalex publication_date 2005/05/14 · arxiv created 2005/05/18 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
Using the OPAL detector at LEP, the running of the effective QED coupling alpha(t) is measured for space-like momentum transfer, 2 ≤ -t ≤ 6 GeV2, from the angular distribution of small-angle Bhabha scattering. This is currently the most significant direct observation of the running of the QED coupling in a single experiment and the first clear evidence of the hadronic contribution to the running in the space-like region. Our result is in good agreement with standard evaluations of alpha(t), based on data in the time-like region.