Upper Limit on the Photoproduction Cross Section of the Spin-Exotic $\ddot{I}{€}_1(1600)$

Abstract

The spin-exotic hybrid meson $\ddot{I}{€}_1(1600)$ is predicted to have a large decay rate to the $\ddot{I}‰\ddot{I}€\ddot{I}€$ final state. Using 76.6~pb${}^{-1}$ of data collected with the GlueX detector, we measure the cross sections for the reactions ${\hat{I}}^{3}p\to \ddot{I}‰\ddot{I}{€}^{+}\ddot{I}{€}^{-}p$, ${\hat{I}}^{3}p\to \ddot{I}‰\ddot{I}{€}^0\ddot{I}{€}^{0}p$, and ${\hat{I}}^{3}p\to \ddot{I}‰\ddot{I}{€}^{-}\ddot{I}{€}^0\hat{I}{”}^{++}$ in the range $E_{\hat{I}}^3=$ 8-10 GeV. Using isospin conservation, we set the first upper limits on the photoproduction cross sections of the $\ddot{I}{€}_1^0(1600)$ and $\ddot{I}{€}_1^{-}(1600)$. We combine these limits with lattice calculations of decay widths and find that photoproduction of $\hat{I}{\cdot }^{\prime }\ddot{I}€$ is the most sensitive two-body system to search for the $\ddot{I}{€}_1(1600)$.

7 pages, 3 figures plus supplemental materials