First observation of the decay $\bar{B}^0_s \to D^0 K^{*0}$ and a measurement of the ratio of branching fractions $\frac{{\cal B}(\bar{B}^0_s \to D^0 K^{*0})}{{\cal B}(\bar{B}^0 \to D^0 \rho^0)}$

TL;DR

This paper reports the first observation of the decay _s   D K^{*0} using LHCb data at 7 TeV, measuring its branching fraction relative to   D ho^0 with high statistical significance.

Contribution

It presents the first observation and measurement of the _s   D K^{*0} decay, expanding knowledge of B meson decay modes.

Findings

First observation of _s   D K^{*0} decay

Measured ratio of branching fractions: 1.48 b0 0.34 b0 0.15 b0 0.12

Signal significance exceeds nine standard deviations

Abstract

The first observation of the decay $\bar{B}^0_s \to D^0 K^{*0}$ using $pp$ data collected by the LHCb detector at a centre-of-mass energy of 7 TeV, corresponding to an integrated luminosity of 36 pb$^{-1}$, is reported. A signal of $34.4 \pm 6.8$ events is obtained and the absence of signal is rejected with a statistical significance of more than nine standard deviations. The $\bar{B}^0_s \to D^0 K^{*0}$ branching fraction is measured relative to that of $\bar{B}^0 \to D^0 \rho^0$: $\frac{{\cal B}(\bar{B}^0_s \to D^0 K^{*0})}{{\cal B}(\bar{B}^0 \to D^0 \rho^0)} = 1.48 \pm 0.34 \pm 0.15 \pm 0.12$, where the first uncertainty is statistical, the second systematic and the third is due to the uncertainty on the ratio of the $B^0$ and $B^0_s$ hadronisation fractions.