A study of $CP$ violation in $B^\mp \rightarrow Dh^\mp$ ($h=K,\pi$) with the modes $D \rightarrow K^\mp \pi^\pm \pi^0$, $D \rightarrow \pi^+\pi^-\pi^0$ and $D \rightarrow K^+K^-\pi^0$

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Abstract

An analysis of the decays of $B^\mp \rightarrow D K^\mp$ and $B^\mp \rightarrow D \pi^\mp$ is presented in which the $D$ meson is reconstructed in the three-body final states $K^\mp \pi^\pm \pi^0$, $\pi^+ \pi^- \pi^0$ and $K^+ K^- \pi^0$. Using data from LHCb corresponding to an integrated luminosity of 3.0 fb$^{-1}$ of $pp$ collisions, measurements of several $CP$ observables are performed. First observations are obtained of the suppressed ADS decay $B^\mp \rightarrow [\pi^\mp K^\pm \pi^0]_D \pi^\mp$ and the quasi-GLW decay $B^\mp \rightarrow [K^+ K^- \pi^0]_D \pi^\mp$. The results are interpreted in the context of the unitarity triangle angle $\gamma$ and related parameters.

Figures and captions

 Invariant mass distributions of selected \favBToDHWithDToKPiPi0 candidates, separated by $B$ hadron charge. $B ^\mp \rightarrow D K ^\mp$ signal events are in the upper plots and \BToDPi events are in the lower plots. The solid dark (red) curve represents $B ^\mp \rightarrow D K ^\mp$ events and the solid light (green) curve represents \BToDPi events. The solid (grey) shape indicates partially reconstructed $B ^\mp$ decays and the heavy dotted (red) curve indicates wrongly reconstructed $D$ decays. The solid (blue) line represents the total PDF and includes the combinatorial component. canvas[..].pdf [35 KiB] HiDef png [335 KiB] Thumbnail [196 KiB] *.C file Invariant mass distributions of selected \supBToDHWithDToKPiPi0 candidates. See the caption of Fig. 1 for a full description. The lightly dotted (blue) line represents the combinatorial component and the long-dashed (magenta) line indicates contributions from partially reconstructed $B ^0_ s \rightarrow D K ^\mp \pi ^\pm$ decays where the pion is not reconstructed. canvas[..].pdf [33 KiB] HiDef png [309 KiB] Thumbnail [207 KiB] *.C file Invariant mass distributions of selected \BToDHWithDToPiPiPi0 candidates. See the caption of Fig. 1 for a full description. The lightly dotted (blue) line represents the combinatorial component. canvas[..].pdf [36 KiB] HiDef png [360 KiB] Thumbnail [225 KiB] *.C file Invariant mass distributions of selected \BToDHWithDToKKPi0 candidates. See the caption of Fig. 1 for a full description. The lightly dotted (blue) line represents the combinatorial component. canvas[..].pdf [33 KiB] HiDef png [337 KiB] Thumbnail [214 KiB] *.C file Scan of the $\chi^2$ probabilities over the $\gamma$ --$r_B$ parameter space. Shown are the $n\sigma$ profile likelihood contours, where $\Delta\chi^2 = n^2$, with $n=1$ being the light (blue) shaded region, $n=2$ the dark (blue) shaded region and $n=3$ corresponding to the white area. The result is seen to be compatible with the current LHCb measurement of $\gamma$ and $r_B$, indicated by the point with error bars. rB_vs_[..].pdf [151 KiB] HiDef png [1 MiB] Thumbnail [885 KiB] *.C file Scan of the $\chi^2$ probabilities over the $\gamma$ --$\delta_B$ parameter space. Shown are the $n\sigma$ profile likelihood contours, where $\Delta\chi^2 = n^2$, with $n=1$ being the light (blue) shaded region, $n=2$ the dark (blue) shaded region and $n=3$ corresponding to the white area. The result is compatible with the current LHCb measurement of $\gamma$ and $\delta_B$, indicated by the point with error bars. deltaB[..].pdf [152 KiB] HiDef png [1 MiB] Thumbnail [912 KiB] *.C file Animated gif made out of all figures. PAPER-2015-014.gif Thumbnail

Tables and captions

 The final signal yields, split in categories based on the charges of the $B$ hadron (only statistical uncertainties are shown). Table_1.pdf [50 KiB] HiDef png [86 KiB] Thumbnail [45 KiB] tex code Systematic uncertainties on the observables, multiplied by a factor of $10^{3}$. PID' refers to the fixed PID efficiency attributed to the bachelor tracks. PDFs' refers to the uncertainties based on fixed parameters in the PDF shapes that are used in the invariant mass fit. Sim' refers to the use of simulation to calculate relative efficiencies between the $B ^\mp \rightarrow D K ^\mp$ and \BToDPi modes, in addition to the estimated charmless background contributions and the fixed $DK$ to $D\pi$ ratio on the ADS modes. $A_{\rm instr}$' refers to the interaction and detection asymmetries. The `Total' column represents the sum in quadrature of all of the categories of systematic uncertainties. Table_2.pdf [47 KiB] HiDef png [197 KiB] Thumbnail [93 KiB] tex code

Supplementary Material [file]

 Supplementary material full pdf supple[..].pdf [221 KiB] This ZIP file contains supplementary material for the publication LHCb-PAPER-2015-014. The files are: supplementary.pdf : An overview of the extra figures *.pdf, *.png, *.eps, *.C : The figures in various formats FigS1.pdf [30 KiB] HiDef png [355 KiB] Thumbnail [253 KiB] *C file FigS2.pdf [30 KiB] HiDef png [396 KiB] Thumbnail [271 KiB] *C file

Created on 20 September 2019.