Decay into Muon Pairs of PhotoproducedϕMesons

Abstract

We have measured the yield of $\varphi$ mesons photoproduced from carbon and decaying into muon pairs. We find that the product of the lepton-pair branching ratio for the $\varphi$ and the $t=0\mathrm{}$ photoproduction cross section is (0.66 ± 0.10) × ${10}^{-4\mathrm{}}$ mb/Ge${\mathrm{V}}^2$. This number is compared with existing measurements of the branching ratio and the cross section.