Dalitz plot analysis and branching fraction measurement of D+ and Ds+ -> pi+pi-pi+

Abstract

Fermilab fixed target experiment E791 obtained a sample of $1172\pm 61$ events of $D^{+}\to {\pi }^{-}{\pi }^{+}{\pi }^{+}$ and 848 $\pm 44$ events of $D_s^{+}\to {\pi }^{-}{\pi }^{+}{\pi }^{+}$ decays. We find respectively $B(D^{+}\to {\pi }^{-}{\pi }^{+}{\pi }^{+})/B(D^{+}\to K^{-}{\pi }^{+}{\pi }^{+})=0.0311\pm 0.0018_{-0.0026}^{+0.0016}$ and $B(D_s^{+}\to {\pi }^{+}{\pi }^{-}{\pi }^{+})/B(D_s^{+}\to \varphi {\pi }^{+})=0.245\pm 0.028_{-0.012}^{+0.019}$. Using a coherent amplitude analysis to fit the Dalitz plot of the $D^{+}\to {\pi }^{-}{\pi }^{+}{\pi }^{+}$ decay, we find strong evidence for a scalar resonance of mass $478_{-23}^{+24}\pm 17$MeV/$c^2$ and width $324_{-40}^{+42}\pm 21$ MeV/$c^2$, compatible with what is expected for the isoscalar meson $\sigma$ >. The $D^{+}\to \sigma (500){\pi }^{+}$ fraction accounts for approximately half of all three-charged-pion decays of the $D^{+}$ . From the Dalitz plot analysis of the $D_s^{+}\to {\pi }^{-}{\pi }^{+}{\pi }^{+}$ decay events, we find significant contributions from the channels ${\rho }^0(770){\pi }^{+}$, ${\rho }^0(1450){\pi }^{+}$, $f_0(980){\pi }^{+}$, $f_2(1270){\pi }^{+}$, and $f_0(1370){\pi }^{+}$. We also present new measurement of the masses and widths of the isoscalar resonances $f_0(980)$ and $f_0(1370)$.

4 pages, 4 figures, talk presented in BEACH2000, Valencia, Spain

References in corpus (1)

• Predicting D -> sigma pi