Speaker
Alessio Mangoni
(INFN Perugia)
Description
Assuming the isospin conservation, the electromagnetic amplitudes of the decays $\psi \to \Lambda \overline \Sigma^0 + \rm{c.c.}$, where $\psi=J/\psi, \psi(2S)$, and of the processes $e^+e^- \to \Lambda \overline \Sigma{}^0 + \rm{c.c.}$ at the $\psi$ mass are parametrized by the same coupling. By using BESIII and BABAR data we find a substantial discrepancy between the values of the modulus of the same electromagnetic coupling extracted from the branching ratios and the cross sections. This fact suggests the presence of isospin-violating contributions, especially in the $\psi(2S)$ case.
Primary authors
Alessio Mangoni
(INFN Perugia)
Prof.
Simone Pacetti
(INFN Perugia & Università di Perugia)
Prof.
Rinaldo Baldini Ferroli
(LNF INFN)
