Photoproduction of the $f_2(1270)$ meson using the CLAS detector

Abstract

The quark structure of the $f_2(1270)$ meson has, for many years, been assumed to be a pure quark-antiquark ($q\bar{q}$) resonance with quantum numbers $J^{PC}=2^{++}$. Recently, it was proposed that the $f_2(1270)$ is a molecular state made from the attractive interaction of two $\ddot{I}$-mesons. Such a state would be expected to decay strongly to final states with charged pions, due to the dominant decay $\ddot{I}\to \ddot{I}{€}^{+}\ddot{I}{€}^{-}$, whereas decay to two neutral pions would likely be suppressed. Here, we measure for the first time the reaction ${\hat{I}}^{3}p\to \ddot{I}{€}^0\ddot{I}{€}^{0}p$, using the CLAS detector at Jefferson Lab for incident beam energies between 3.6-5.4~GeV. Differential cross sections, $d\ddot{I}ƒ/dt$, for $f_2(1270)$ photoproduction are extracted with good precision, due to low backgrounds, and are compared with theoretical calculations.

5 pages, 4 figures