Measurements of the branching fractions of the inclusive decays $D^{0}(D^{+})\to \pi^+\pi^+\pi^-X$

TL;DR

This paper reports the first measurements of inclusive decay branching fractions of D mesons into three pions plus any other particles, using data from the BESIII detector at 3.773 GeV.

Contribution

It provides the first experimental determination of the inclusive decay branching fractions for D0 and D+ mesons into three pions plus any particles, excluding those from K0_S decays.

Findings

Branching fraction for D0→π+π+π−X is (17.60±0.11±0.22)%

Branching fraction for D+→π+π+π−X is (15.25±0.09±0.18)%

First measurements of these inclusive decay modes.

Abstract

Using $e^+e^-$ annihilation data corresponding to an integrated luminosity of 2.93 fb$^{-1}$ taken at a center-of-mass energy of 3.773 GeV with the BESIII detector, we report the first measurements of the branching fractions of the inclusive decays $D^0\to \pi^+\pi^+\pi^-X$ and $D^+\to \pi^+\pi^+\pi^-X$, where pions from $K^0_S$ decays have been excluded from the $\pi^+\pi^+\pi^-$ system and $X$ denotes any possible particle combination. The branching fractions of $D^0(D^+)\to \pi^+\pi^+\pi^-X$ are determined to be ${\mathcal B}(D^0\to \pi^+\pi^+\pi^-X)=(17.60\pm0.11\pm0.22)\%$ and ${\mathcal B}(D^+\to \pi^+\pi^+\pi^-X)=(15.25\pm0.09\pm0.18)\%$, where the first uncertainties are statistical and the second systematic.