Study of the exclusive initial-state-radiation production of the D¯¯¯D system

Abstract

A search for charmonium and other new states is performed in a study of exclusive initial-state-radiation production of D ¯¯¯ D events from electron-positron annihilations at a center-of-mass energy of 10.58 GeV. The data sample corresponds to an integrated luminosity of 384 fb − 1 and was recorded by the BABAR experiment at the PEP-II storage ring. The D ¯¯¯ D mass spectrum shows clear evidence of the ψ ( 3770 ) plus other structures near 3.9, 4.1, and 4.4 GeV / c 2 . No evidence for Y ( 4260 ) → D ¯¯¯ D is observed, leading to an upper limit of B ( Y ( 4260 ) → D ¯¯¯ D ) / B ( Y ( 4260 ) → J / ψ π + π − ) < 1.0 at 90% confidence level.