Production of ${\rm f_0}(980)$, ${\rm f}_2(1270)$ and $\phi(1020)$ in hadronic ${\rm Z}^0$ decay

Abstract.

Inclusive production of the ${\rm f_0}(980)$, ${\rm f}_2(1270)$ and $\phi(1020)$ resonances has been studied in a sample of 4.3 million hadronic ${\rm Z}^0$ decays from the OPAL experiment at LEP. A coupled channel analysis has been used for the ${\rm f}_0$ in simultaneous fits to the resonances in inclusive $\pi^+\pi^-$ and ${\rm K^+K^-}$ mass spectra. Fragmentation functions are reported for the three states. Total inclusive rates are measured to be $0.141 \pm 0.007 \pm 0.011$ ${\rm f}_0$, $0.155\pm0.011\pm0.018$ ${\rm f}_2$ and $0.091\pm0.002\pm0.003$ $\phi$ mesons per hadronic ${\rm Z}^0$ decay. The production properties of the ${\rm f}_0$, including those in three-jet events, are compared with those of the ${\rm f}_2$ and $\phi$, and with the Lund string model of hadron production. All measurements are consistent with the hypothesis that the ${\rm f_0}(980)$ is a conventional ${\rm q\bar q}$ scalar meson.