Search for X(3872) in gamma gamma Fusion and ISR at CLEO

TL;DR

This study searches for the X(3872) particle in gamma gamma fusion and initial state radiation at CLEO, setting upper limits on its production rates but not observing a signal.

Contribution

First search for X(3872) in gamma gamma fusion and ISR at CLEO, providing upper limits on production rates in these channels.

Findings

No evidence of X(3872) observed in either production mode.

Established 90% confidence upper limits on production rates.

Results constrain models of X(3872) production mechanisms.

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 sqrt{s} = 9.46-11.30 GeV region. Separate searches for the production of X(3872) in untagged gamma gamma fusion and e+ e- annihilation following initial state radiation are made by taking advantage of the unique correlation of J/psi -> l+ l- in X(3872) decay into J/psi pi+ pi-. No signals are observed in either case, and 90% confidence upper limits are established as (2J+1)Gamma_{gammagamma}(X(3872))B(X -> J/psi pi+ pi-) < 12.9 eV and Gamma_{ee}(X(3872))B(X -> J/psi pi+ pi-) < 8.3 eV.