The first observation of the decay B0 -> D0bar K+ K- is reported from an analysis of 0.62 fb-1 of pp collision data collected with the LHCb detector. Its branching fraction is measured relative to that of the topologically similar decay B0 -> D0bar pi+ pi- to be BR(B0 -> D0bar K+ K-)/BR(B0 -> D0bar pi+ pi-) = 0.056+-0.011+-0.007, where the first uncertainty is statistical and the second is systematic. The significance of the signal is 5.8 sigma. Evidence, with 3.8 sigma significance, for Bs -> D0bar K+ K- decays is also presented, with a relative branching fraction of BR(Bs -> D0bar K+ K-)/BR(B0 -> D0bar K+ K-) = 0.90+-0.27+-0.20.
Sample decay diagrams that contribute to the $ B ^0 \rightarrow \overline{ D }{} ^0 K ^+ K ^- $ final state via (left) $W$-exchange, (right) rescattering from a colour-suppressed decay. |
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Fits to the $ B ^0_{( s )} $ candidate invariant mass distributions for the (left) $\overline{ D }{} ^0 \pi ^+ \pi ^- $ and (right) $\overline{ D }{} ^0 K ^+ K ^- $ samples. Data points are shown in black, the full fitted PDFs as solid blue lines and the components as detailed in the legends. Yields of the partially reconstructed and peaking backgrounds are all small for the $\overline{ D }{} ^0 K ^+ K ^- $ sample. |
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Dalitz plot distributions for (left) $ B ^0 \rightarrow \overline{ D }{} ^0 \pi ^+ \pi ^- $ and (right) $ B ^0 \rightarrow \overline{ D }{} ^0 K ^+ K ^- $ obtained from the signal weights. Note that these distributions contain contributions from charmless peaking backgrounds. |
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DKK_DP[..].pdf [6 KiB] HiDef png [110 KiB] Thumbnail [79 KiB] *.C file |
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Animated gif made out of all figures. |
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Supplementary material full pdf |
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- Supplementary.pdf The supplementary material to the paper LHCb-PAPER-2012-018 - *.pdf *.eps *.png The figures in various formats |
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Figsupb.pdf [10 KiB] HiDef png [210 KiB] Thumbnail [176 KiB] *C file |
Created on 02 May 2024.