# Measurement of $C\!P$ observables in the process $B^0 \to DK^{*0}$ with two- and four-body $D$ decays

## TL;DR

This paper reports measurements of $CP$ observables in $B^0 o DK^{*0}$ decays, utilizing both two- and four-body $D$ decay modes, including first observations of certain decay channels, to extract the $CP$-violating phase $oldsymbol{\gamma}$.

## Contribution

It introduces the first measurements of $CP$ observables in $B^0 o DK^{*0}$ decays with four-body $D$ decays and observes new decay channels, enhancing understanding of $CP$ violation.

## Key findings

- First observations of $B^0 o D( ext{π}^+ ext{K}^-)K^{*0}$ and $B^0 o D( ext{π}^+ ext{π}^- ext{π}^+ ext{π}^-)K^{*0}$ decays.
- Measurements of $CP$ observables in multiple $D$ decay modes.
- Interpretation of results in terms of the $CP$-violating phase $oldsymbol{\gamma}$.

## Abstract

Measurements of $C\!P$ observables in $B^0 \to DK^{*0}$ decays are presented, where $D$ represents a superposition of $D^0$ and $\bar{D}^0$ states. The $D$ meson is reconstructed in the two-body final states $K^+\pi^-$, $\pi^+ K^-$, $K^+K^-$ and $\pi^+\pi^-$, and, for the first time, in the four-body final states $K^+\pi^-\pi^+\pi^-$, $\pi^+ K^-\pi^+\pi^-$ and $\pi^+\pi^-\pi^+\pi^-$. The analysis uses a sample of neutral $B$ mesons produced in proton-proton collisions, corresponding to an integrated luminosity of 1.0, 2.0 and 1.8 $\rm fb^{-1}$ collected with the LHCb detector at centre-of-mass energies of $\sqrt{s} = $ 7, 8 and 13 TeV, respectively. First observations of the decays $B^0 \to D(\pi^+ K^-)K^{*0}$ and $B^0 \to D(\pi^+\pi^-\pi^+\pi^-)K^{*0}$ are obtained. The measured observables are interpreted in terms of the $C\!P$-violating weak phase $\gamma$.