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Title: Measurement of $CP$ violation observables and parameters for the decays
$B^{\pm}\to D K^{*\pm}$.
Authors: The BABAR Collaboration, B. Aubert et al.
Comments: 15 pages, 13 postscript(eps) figures, submitted to PRD
Report-no: BABAR-PUB-09/019, SLAC-PUB-13793
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We study the decay $B^-\to DK^{*-}$ using a sample of 379$\times 10^6$ $\Upsilon(4S)\to B\bar{B}$ events collected
with the BABAR detector at the PEP-II $B$-factory. We perform a ``GLW'' analysis where the $D$ meson decays
into either a $CP$-even ($CP+$) eigenstate ($K^+K^-$, $\pi^+\pi^-$), $CP$-odd ($CP-$) eigenstate ($K^0_S\pi^0$, $K^0_S\phi$,
$K^0_S\omega$) or a non-$CP$ state ($K^-\pi^+$). We also analyze $D$ meson decays into $K^+\pi^-$ from a Cabibbo-favored
$\overline{D}^0$ decay or doubly suppressed $D^0$ decay (``ADS'' analysis). We measure observables
that are sensitive to the CKM angle $\gamma$: the partial-rate charge asymmetries ${\cal A}_{CP\pm}$,
the ratios ${\cal R}_{CP\pm}$ of the $B$-decay branching fractions in $CP\pm$ and non-$CP$ decay,
the ratio ${\cal R}_{ADS}$ of the charge-averaged branching fractions, and the charge asymmetry
${\cal A}_{ADS}$ of the ADS decays:
${\cal A}_{CP+}= 0.09 \pm 0.13 \pm 0.06$,
${\cal A}_{CP-}= -0.23 \pm 0.21 \pm 0.07$,
${\cal R}_{CP+} =2.17 \pm 0.35 \pm 0.09$,
${\cal R}_{CP-} = 1.03 \pm 0.27 \pm 0.13$,
${\cal R}_{ADS} =0.066 \pm 0.031 \pm 0.010$, and
${\cal A}_{ADS} = -0.34 \pm 0.43 \pm 0.16$,
where the first uncertainty is statistical and the second is systematic.
Combining all the measurements and using a frequentist approach
yields the magnitude of the ratio between the Cabibbo-suppressed and favored amplitudes,
$r_B$ = 0.31 with a one (two) sigma confidence
level interval
of [0.24, 0.38] ([0.17, 0.43]). The value $r_B=0$ is excluded at the 3.3 sigma level.
A similar analysis
excludes values of $\gamma$ in the intervals
$[0,~7]^{\circ},~[55,~111]^{\circ}$, and $[175,~180]^{\circ}$ ([85, 99]$^{\circ}$)
at the one (two) sigma confidence level.
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