Measurements of $B\to \bar{D}{D}_{s0}^{\ast +}(2317)$ decay rates and a search for isospin partners of the $D_{s0}^{\ast +}(2317)$

Abstract

We report improved measurements of the product branching fractions $\mathcal{B}(B^{+}\to {\bar{D}}^0{D}_{s0}^{\ast +}(2317))\times \mathcal{B}(D_{s0}^{\ast +}(2317)\to D_s^{+}\ddot{I}{€}^0)=(8.0_{-1.2}^{+1.3}\pm 1.1\pm 0.4)\times 10^{-4}$ and $\mathcal{B}(B^0\to D^{-}{D}_{s0}^{\ast +}(2317))\times \mathcal{B}(D_{s0}^{\ast +}(2317)\to D_s^{+}\ddot{I}{€}^0)=(10.2_{-1.2}^{+1.3}\pm 1.0\pm 0.4)\times 10^{-4}$, where the first errors are statistical, the second are systematic and the third are from $D$ and $D_s$ branching fractions. In addition, we report negative results from a search for hypothesized neutral ($Z^0$) and doubly charged ($Z^{++}$) isospin partners of the $D_{s0}^{\ast +}(2317)$ and provide upper limits on the product branching fractions $\mathcal{B}(B^0\to D^0{z}^0)\times \mathcal{B}(z^0\to D_s^{+}\ddot{I}{€}^{-})$ and $\mathcal{B}(B^{+}\to D^{-}{z}^{++})\times \mathcal{B}(z^{++}\to D_s^{+}\ddot{I}{€}^{+})$ that are more than an order of magnitude smaller than theoretical expectations for the hypotheses that the $D_{s0}^{\ast +}(2317)$ is a member of an isospin triplet. The analysis uses a 711 fb${}^{-1}$ data sample containing 772 million $B\bar{B}$ meson pairs collected at the $\hat{I}\yen (4S)$ resonance in the Belle detector at the KEKB collider.

11 pages, 7 figures, es2015apr10_546