cern.ch

Observation of $B_{c}^{+} \to J/\psi D^{(*)} K^{(*)}$ decays

[to restricted-access page]

Information

Tools

Abstract

A search for the decays $B_c^+ \to J/\psi D^{(*)0} K^+$ and $B_c^+ \to J/\psi D^{(*)+} K^{*0}$ is performed with data collected at the LHCb experiment corresponding to an integrated luminosity of 3 fb$^{-1}$. The decays $B_c^+ \to J/\psi D^0 K^+$ and $B_c^+ \to J/\psi D^{*0} K^+$ are observed for the first time, while first evidence is reported for the $B_c^+ \to J/\psi D^{*+} K^{*0}$ and $B_c^+ \to J/\psi D^+ K^{*0}$ decays. The branching fractions of these decays are determined relative to the $B_c^+ \to J/\psi \pi^+$ decay. The $B_c^+$ mass is measured, using the $J/\psi D^0 K^+$ final state, to be $6274.28 \pm 1.40 (stat) \pm 0.32 (syst)$ MeV/$c^2$. This is the most precise single measurement of the $B_c^+$ mass to date.

Figures and captions

Diagrams for $ B _ c ^+ \rightarrow { J \mskip -3mu/\mskip -2mu\psi \mskip 2mu} D ^{(*)} K ^{(*)}$ decays mediated by $\overline b \rightarrow c \bar{c} \bar{s}$ and annihilation amplitudes.

 Fig1a.pdf [110 KiB]
HiDef png [51 KiB]
Thumbnail [30 KiB]
*.C file
Fig1a.pdf
Fig1b.pdf [110 KiB]
HiDef png [58 KiB]
Thumbnail [33 KiB]
*.C file
Fig1b.pdf
Fig1c.pdf [110 KiB]
HiDef png [63 KiB]
Thumbnail [38 KiB]
*.C file
Fig1c.pdf

The invariant mass distribution of $ { J \mskip -3mu/\mskip -2mu\psi \mskip 2mu} D ^0 K ^+ $ candidates: (a) $ D ^0 \rightarrow K ^- \pi ^+ $ and $ D ^0 \rightarrow K ^- \pi ^+ \pi ^- \pi ^+ $ combined; (b) $ D ^0 \rightarrow K ^- \pi ^+ $ only, and the events are required to be TOS.

 Fig2a.pdf [23 KiB]
HiDef png [276 KiB]
Thumbnail [237 KiB]
*.C file
Fig2a.pdf
Fig2b.pdf [22 KiB]
HiDef png [272 KiB]
Thumbnail [237 KiB]
*.C file
Fig2b.pdf

The invariant mass distribution of (a,b) $ { J \mskip -3mu/\mskip -2mu\psi \mskip 2mu} D ^0 $, (c,d) $ D ^0 K ^+ $ and (e,f) $ { J \mskip -3mu/\mskip -2mu\psi \mskip 2mu} K ^+ $ combinations of background-subtracted (a,c,e) $ B _ c ^+ \rightarrow { J \mskip -3mu/\mskip -2mu\psi \mskip 2mu} D ^0 K ^+ $ and (b,d,f) $ B _ c ^+ \rightarrow { J \mskip -3mu/\mskip -2mu\psi \mskip 2mu} D ^{*0} K ^+ $ decays, where the $\gamma$ or $\pi ^0 $ in the $ D ^{*0} \rightarrow D ^0 \gamma/ D ^0 \pi ^0 $ decay is not reconstructed. Dashed lines show simulation assuming phase-space decay.

 Fig3a.pdf [17 KiB]
HiDef png [170 KiB]
Thumbnail [165 KiB]
*.C file
Fig3a.pdf
Fig3b.pdf [17 KiB]
HiDef png [173 KiB]
Thumbnail [164 KiB]
*.C file
Fig3b.pdf
Fig3c.pdf [18 KiB]
HiDef png [167 KiB]
Thumbnail [163 KiB]
*.C file
Fig3c.pdf
Fig3d.pdf [18 KiB]
HiDef png [174 KiB]
Thumbnail [171 KiB]
*.C file
Fig3d.pdf
Fig3e.pdf [18 KiB]
HiDef png [171 KiB]
Thumbnail [166 KiB]
*.C file
Fig3e.pdf
Fig3f.pdf [18 KiB]
HiDef png [177 KiB]
Thumbnail [168 KiB]
*.C file
Fig3f.pdf

The invariant mass distribution of (a,c) the $ B _ c ^+ \rightarrow { J \mskip -3mu/\mskip -2mu\psi \mskip 2mu} D ^{*+} K ^{*0} $ and (b,d) $ { J \mskip -3mu/\mskip -2mu\psi \mskip 2mu} D ^+ K ^{*0} $ candidates, (a,b) without and (c,d) with TOS requirements.

 Fig4a.pdf [20 KiB]
HiDef png [225 KiB]
Thumbnail [185 KiB]
*.C file
Fig4a.pdf
Fig4b.pdf [18 KiB]
HiDef png [216 KiB]
Thumbnail [170 KiB]
*.C file
Fig4b.pdf
Fig4c.pdf [20 KiB]
HiDef png [229 KiB]
Thumbnail [194 KiB]
*.C file
Fig4c.pdf
Fig4d.pdf [18 KiB]
HiDef png [227 KiB]
Thumbnail [179 KiB]
*.C file
Fig4d.pdf

The invariant mass distribution of the $ B _ c ^+ \rightarrow { J \mskip -3mu/\mskip -2mu\psi \mskip 2mu} \pi ^+ $ candidates.

 Fig5.pdf [32 KiB]
HiDef png [254 KiB]
Thumbnail [210 KiB]
*.C file
Fig5.pdf

Animated gif made out of all figures.

 PAPER-2016-055.gif
Thumbnail
thumbnail_PAPER-2016-055.gif

Tables and captions

Summary of systematic uncertainties on the ratios of the $ B _ c ^+ $ decay branching fractions, in %.

 Table_1.pdf [60 KiB]
HiDef png [59 KiB]
Thumbnail [23 KiB]
tex code 		Table_1.pdf

Summary of systematic uncertainties of the $ B _ c ^+$ mass measurement.

 Table_2.pdf [31 KiB]
HiDef png [63 KiB]
Thumbnail [28 KiB]
tex code 		Table_2.pdf

Supplementary Material [file]

Supplementary material full pdf

 supple[..].pdf [108 KiB]
 supplementary.pdf

This ZIP file contains supplemetary material for the publication LHCb-PAPER-2016-055. The files are: supplementary.pdf : An overview of the extra figures *.pdf, *.png, *.eps : The figures in variuous formats

 Fig1.pdf [13 KiB]
HiDef png [189 KiB]
Thumbnail [173 KiB]
*C file
Fig1.pdf

Created on 26 April 2024.