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 ISR processes at CLEO but finds no evidence, setting upper limits on its production rates in these channels.

Contribution

First search for X(3872) in gamma-gamma fusion and ISR at CLEO, establishing upper limits on production cross sections and decay branching ratios.

Findings

No signals observed for X(3872) in either process.

Established 90% confidence upper limits on production rates.

Provided constraints on X(3872) properties in these channels.

Abstract

We report on a search for the recently reported X(3872) state using 15.1 fb^{-1} e+ e- data taken 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 (ISR) are made by taking advantage of the unique correlation of J/psi -> l+ l- in X(3872) decay to pi+ pi- J/psi. No signals are observed in either case, and 90% confidence upper limits are established as (2J+1)\Gamma_{\gamma\gamma}B(X -> pi+ pi- J/psi) < 12.9 eV and \Gamma_{ee}B(X -> pi+ pi- J/psi) < 8.3 eV.