We study initial-state radiation events, e(+)e(-)->gamma(ISR)pi(+)pi(-)J/psi, with data collected with the BABAR detector. We observe an accumulation of events near 4.26 GeV/c(2) in the invariant-mass spectrum of pi(+)pi(-)J/psi. Fits to the mass spectrum indicate that a broad resonance with a mass of about 4.26 GeV/c(2) is required to describe the observed structure. The presence of additional narrow resonances cannot be excluded. The fitted width of the broad resonance is 50 to 90 MeV/c(2), depending on the fit hypothesis. RI Peters, Klaus/C-2728-2008; de Groot, Nicolo/A-2675-2009; Patrignani, Claudia/C-5223-2009; Lista, Luca/C-5719-2008; Bellini, Fabio/D-1055-2009; Roe, Natalie/A-8798-2012; Neri, Nicola/G-3991-2012; Monge, Maria Roberta/G-9127-2012
Observation of a broad structure in the pi(+)pi(-)J/psi mass spectrum around 4.26 GeV/c(2)
ANGELINI, CARLO;BATIGNANI, GIOVANNI;BETTARINI, STEFANO;CALDERINI, GIOVANNI;FORTI, FRANCESCO;GIORGI, MARCELLO;PAOLONI, EUGENIO;RIZZO, GIULIANA;
2005-01-01
Abstract
We study initial-state radiation events, e(+)e(-)->gamma(ISR)pi(+)pi(-)J/psi, with data collected with the BABAR detector. We observe an accumulation of events near 4.26 GeV/c(2) in the invariant-mass spectrum of pi(+)pi(-)J/psi. Fits to the mass spectrum indicate that a broad resonance with a mass of about 4.26 GeV/c(2) is required to describe the observed structure. The presence of additional narrow resonances cannot be excluded. The fitted width of the broad resonance is 50 to 90 MeV/c(2), depending on the fit hypothesis. RI Peters, Klaus/C-2728-2008; de Groot, Nicolo/A-2675-2009; Patrignani, Claudia/C-5223-2009; Lista, Luca/C-5719-2008; Bellini, Fabio/D-1055-2009; Roe, Natalie/A-8798-2012; Neri, Nicola/G-3991-2012; Monge, Maria Roberta/G-9127-2012I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
