Speaker
Mr
Andrey Sukharev
(Budker INP)
Description
Since 2004 KEDR detector at VEPP-4M collider has taken several data sets in psi(2s) region, acquiring total luminosity of about 7 pb^{-1}, which corresponds to
more than 3.5 \times 10^6 psi(2s).
There were 5 scans of the resonance allowing us to know the collider's energy spread and 5 runs where the data was taken at the psi(2s) peak and slightly below it.
We report the value of
\Gamma_{ee}\times B_{\mu\mu} = 20.5 \pm 0.5 \pm 1.0 eV.
No direct measurement of this quantity is listed in the PDG tables yet.
Primary author
Mr
Andrey Sukharev
(Budker INP)
