title: Charmed baryonium.
abstract: We reanalyze the published data on the Y(4630)-->Lambda(c) Lambda(c) and the Y(4660)-->psi(2S)pi pi with a consistent ansatz and we find that the two observations are likely to be due to the same state Y(B), produced via initial state radiation (ISR), with M(Y(B))=4660.7+/-8.7 MeV and Gamma(Y(B))=61+/-23 MeV. Under this hypothesis and reanalyzing the e+e- -->J/psi pi pi gamma(ISR) spectrum we find B(Y(B))-->Lambda(c) Lambda(c))/B(Y(B))-->psi(2S)pi pi)=117+/-44, B(Y(B))-->J/psi pi pi)/B(Y(B))-->psi(2S)pi pi)<0.46@90% C.L., B(Y(4350)-->J/psi pi pi)/B(Y(4350)-->psi(2S)pi pi)<3.4x10(-3)@90% C.L., and B(Y(B))-->psi(2S)sigma)/B(Y(B))-->psi(2S)f0)=2.0+/-0.3. These conclusions strongly support the hypothesis of Y(B) being the first observation of a charmed baryonium constituted by four quarks. Analyzing the mass spectrum we show that Y(4350) and Y(B) are, respectively, consistent with the ground state and first radial excitation of the l=1 state.
authors.affiliation: Department of Physics, Università di Roma, La Sapienza, Piazzale A. Moro 2, Roma, I-00185, Italy.
authors.forename: G
authors.initials: G
authors.lastname: Cotugno
authors.forename: R
authors.initials: R
authors.lastname: Faccini
authors.forename: A D
authors.initials: AD
authors.lastname: Polosa
authors.forename: C
authors.initials: C
authors.lastname: Sabelli