Observation of the Isospin-Violating Decay $D_s^{*+}\to D_s^+\pi^0$

TL;DR

This paper reports the first observation of the isospin-violating decay of the $D_s^{*+}$ meson into $D_s^+ ext{ and } ext{pi}^0$, measuring its decay rate relative to the dominant radiative decay.

Contribution

The study provides the first measurement of the decay rate of $D_s^{*+} o D_s^+ ext{ pi}^0$ relative to $D_s^{*+} o D_s^+ ext{ gamma}$.

Findings

Decay rate ratio is approximately 0.062.

First observation of this isospin-violating decay.

Quantitative measurement with uncertainties.

Abstract

Using data collected with the CLEO~II detector, we have observed the isospin-violating decay $D_s^{*+}\to D_s^+\pi^0$. The decay rate for this mode, relative to the dominant radiative decay, is found to be $\Gamma(D_s^{*+}\to D_s^+\pi^0)/\Gamma(D_s^{*+}\to D_s^+\gamma)= 0.062^{+0.020}_{-0.018}\pm0.022$.