Speaker
Prof.
Marco Maggiora
(INFN Torino)
Description
Experimental data in various channels show that in $J/\psi$ decay,
strong and electromagnetic amplitudes seem to be orthogonal, while in the standard model
they are expected to be both almost real. There
has been the conjecture that the phase between strong and electromagnetic
amplitudes is universally $-90^\circ$ in all decays of charmonium
(quarkonium) $1^{--}$ states. However, so far the determination of this phase has
been based mostly on theoretical assumptions about SU(3) symmetry. We propose
to measure this phase directly by the scan of the energy region below the charmonium $1^{--}$
resonances. We present the theoretical basis of such measurement
and analyze the feasibility and sensitivity for the data to be eventually taken by
BES-III experiment.
Primary authors
Dr
Ping Wang
(IHEP, Beijing)
Rinaldo Baldini
(LNF, INFN, Italy)