Faculty and Student Publications

Document Type


Publication Date



We report the first evidence for X(3872) production in two-photon interactions by tagging either the electron or the positron in the final state, exploring the highly virtual photon region. The search is performed in e+e-→e+e-J/ψ π+ π-, using 825 fb-1 of data collected by the Belle detector operated at the KEKB e+e-collider. We observe three X(3872) candidates, where the expected background is 0.11±0.10 events, with a significance of 3.2σ. We obtain an estimated value for γB(X(3872)→J/ψ π+ π-) assuming the Q2 dependence predicted by a cc meson model, where-Q2 is the invariant mass squared of the virtual photon. No X(3915)→J/ψ π+ π-candidates are found.

Relational Format

journal article



Accessibility Status

Searchable text


To view the content in your browser, please download Adobe Reader or, alternately,
you may Download the file to your hard drive.

NOTE: The latest versions of Adobe Reader do not support viewing PDF files within Firefox on Mac OS and if you are using a modern (Intel) Mac, there is no official plugin for viewing PDF files within the browser window.