Search for X(3872) in γγ fusion and ISR at CLEO

Abstract

We report on a search for the X(3872) state using 15.1 fb−1 of e+e−. annihilation data taken with the CLEO III detector in the s = 9.46–11.30 GeV region. Separate searches for the production of X(3872) in untagged γγ fusion and e+e− annihilation following initial state radiation (ISR) are made by taking advantage of the unique correlation of J/ψ → l+l− in X(3872) decay into π+π−J/ψ. No signals are observed in either case, and 90% confidence upper limits are established as (2J + 1)Γγγ(X(3872))β(X → π+π−J/ψ) < 12.9 eV and Γee(X(3872))β(X → π+π−J/ψ) < 8.3eV.