Measurement of $e^{+}e^{-}\to\phi\pi^{+}\pi^{-}$ cross sections at center-of-mass energies from 2.00 to 3.08 GeV

Abstract

Using data corresponding to an integrated luminosity of $651~\mathrm{pb}^{-1}$ accumulated at 22 center-of-mass energies from 2.00 to 3.08 GeV by the BESIII experiment, the process $e^{+}e^{-}\to\phi\pi^{+}\pi^{-}$ is studied. The cross sections for $e^{+}e^{-}\to\phi\pi^{+}\pi^{-}$ are consistent with previous results, but with improved precision. To measure the mass and width of the structure observed in the cross section line shape, a combine fit is performed after enhancing the contribution from $\phi f_{0}(980)$. The fit reveals a structure with the mass of $M=2178\pm20\pm5~{\rm MeV}/c^2$ and the width of $\varGamma=140\pm36\pm16~{\rm MeV}$, where the first uncertainties are statistical and the second ones are systematic.