Experimental evidence for a light and broad scalar resonance in $D^{+}\to {\pi }^{-}{\pi }^{+}{\pi }^{+}$ decay

Abstract

From a sample of $1172\pm 61$ $D^{+}\to {\pi }^{-}{\pi }^{+}{\pi }^{+}$ decay, we find $\Gamma (D^{+}\to {\pi }^{-}{\pi }^{+}{\pi }^{+})/\Gamma (D^{+}\to K^{-}{\pi }^{+}{\pi }^{+})=0.0311\pm 0.0018_{-0.0026}^{+0.0016}$. Using a coherent amplitude analysis to fit the Dalitz plot of this decays, we find strong evidence that a scalar resonance of mass $478_{-23}^{+24}\pm 17$ MeV/$c^2$ and width $324_{-40}^{+42}\pm 21$ MeV/$c^2$ accounts for approximately half of all decays.

10 pages, 3 eps figures