Measurement of the absolute branching fraction of the inclusive decay $D_s^{+}\to \ddot{I}{€}^{+}\ddot{I}{€}^{+}\ddot{I}{€}^{-}X$

Abstract

Using an $e^{+}{e}^{-}$ collision data sample with a total integrated luminosity of $3.19$ fb${}^{-1}$ collected with the BESIII detector at a center-of-mass energy of 4.178 GeV, the branching fraction of the inclusive decay of the $D_s^{+}$ meson to final states including at least three charged pions is measured for the first time to be $\mathcal{B}(D_s^{+}\to \ddot{I}{€}^{+}\ddot{I}{€}^{+}\ddot{I}{€}^{-}X)=(32.81\pm 0.35_{\mathrm{stat}}\pm 0.63_{\mathrm{syst}})\%$. In this measurement the charged pions from $K_S^0$ meson decays are excluded. The partial branching fractions of $D_s^{+}\to \ddot{I}{€}^{+}\ddot{I}{€}^{+}\ddot{I}{€}^{-}X$ are also measured as a function of the $\ddot{I}{€}^{+}\ddot{I}{€}^{+}\ddot{I}{€}^{-}$ invariant mass.

13 pages, 4 figures