Probing the structure of ${\chi }_{c1}(3872)$ with photon transition form factors

Abstract

We propose to study the structure of the enigmatic ${\chi }_{c1}(3872)$ axial vector meson through its ${\gamma }_L^{\ast }\gamma \to {\chi }_{c1}(3872)$ transition form factor. We derive a light-front wave function representation of the form factor for the lowest $c\bar{c}$ Fock-state. We found that the reduced width of the state is well within the current experimental bound recently published by the Belle collaboration. This strongly suggests a crucial role of the $c\bar{c}$ Fock-state in the photon-induced production. Our results for the $Q^2$ dependence can be tested by future single tagged $e^{+}{e}^{-}$ experiments, giving further insights into the short-distance structure of this meson.

Comments: 5 pages, 2 figures