Study of the e+e- -> J/psi pi+pi- Process via Initial-State Radiation at BABAR

Many new states have been recently discovered at the B-factories above the DD threshold in the charmonium energy region, while some of them appear to be consistent with conventional cc states, others do not t with any charmonium model expectation. Several interpretations have been proposed to explain their nature: D0D+ molecule and diquark-antidiquark states among many other models have been advanced. Among the new charmonium-like states, the Y (4260) is probably the most intriguing: it has been discovered in 2005 by BABAR experiment in J/psipi+pi- final state after Initial State Radiation. This work is the update of the the rst BABAR analysis with improved selection, and using the full data sample: 454 fb-1 of data recorded at the c.m. energy of the G(4S) resonance. Updated parameters for the Y (4260) state have been obtained (mY 4260 = 4246 +- 5 MeV/c2 and Y 4260 = 75 +- 13 MeV), and the evidence for a new structure around 4500 MeV/c2 with mY = 4492+- 10 MeV/c2 and Y = 63 +- 24 MeV has been found.