Article ID Journal Published Year Pages File Type
5493600 Nuclear and Particle Physics Proceedings 2017 4 Pages PDF
Abstract
A measurement of the effective QED coupling constant αQED(s) in the time-like region 600-975 MeV by using the Initial State Radiation process e+e−→μ+μ−γ will be presented. It represents the first measurement of the running of αQED in this energy region. Our results show more than 5 σ significance on the hadronic contribution to the running of α(s), which is the strongest direct evidence ever achieved both in time- and space-like regions by a single experiment. By using the dipion cross section previously measured at KLOE, the Real and Imaginary part of the shift Δα has been extracted. By fitting the ReΔα, the product of the Branching Fraction BR(ω→e+e−)BR(ω→μ+μ−) has been measured. Status and prospects in γγ physics at KLOE-2 experiment will be also presented.
Related Topics
Physical Sciences and Engineering Physics and Astronomy Nuclear and High Energy Physics
Authors
, ,