A search for $\it{\Xi}^{++}_{cc} \rightarrow D^{+} p K^{-} \pi^{+}$ decays

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Abstract

A search for the $\it{\Xi}^{++}_{cc}$ baryon through the $\it{\Xi}^{++}_{cc} \rightarrow D^{+} p K^{-} \pi^{+}$ decay is performed with a data sample corresponding to an integrated luminosity of 1.7 $\mathrm{fb}^{-1}$ recorded by the LHCb experiment in $pp$ collisions at a centre-of-mass energy of 13 TeV. No significant signal is observed in the mass range from the kinematic threshold of the decay to 3800 $\mathrm{MeV}/c^{2}$. An upper limit is set on the ratio of branching fractions $\mathcal{R} = \frac{\mathcal{B}(\it{\Xi}^{++}_{cc} \rightarrow D^{+} p K^{-} \pi^{+})}{\mathcal{B}(\it{\Xi}^{++}_{cc} \rightarrow \Lambda^{+}_{c} K^{-} \pi^{+}\pi^{+})}$ with $\mathcal{R} < 1.7 \hspace{2pt} (2.1) \times 10^{-2}$ at the 90 (95) confidence level at the known mass of the $\it{\Xi}^{++}_{cc}$ state.

Figures and captions

 The Feynman diagram contributing to the inclusive (left) $\Xi _{ c c }^{++}\rightarrow D ^+ p K ^- \pi ^+$ decay with the analogous (right) $\Xi _{ c c }^{++}\rightarrow \Lambda _ c ^+ K ^- \pi ^+ \pi ^+$ diagram. pub-Dp[..].pdf [20 KiB] HiDef png [139 KiB] Thumbnail [81 KiB] *.C file pub-Lc[..].pdf [20 KiB] HiDef png [147 KiB] Thumbnail [86 KiB] *.C file (left) Invariant-mass distribution of the $D ^+$ candidates after the full selection. The black points represent data and the fit is indicated by the continuous (blue) line with the individual signal and background components represented by the dotted (red) line and dashed (green) line, respectively. (right) Invariant-mass distributions of right-sign (black) $D ^+ p K ^- \pi ^+$, wrong-sign-plus (red) $D ^+ p K ^+ \pi ^+$ and wrong-sign-minus (blue) $D ^+ p K ^- \pi ^-$ data combinations are shown. The control samples have been normalised to the right-sign sample. pub-Dp[..].pdf [25 KiB] HiDef png [305 KiB] Thumbnail [279 KiB] *.C file pub-co[..].pdf [22 KiB] HiDef png [281 KiB] Thumbnail [242 KiB] *.C file (left) Invariant-mass distribution of the ${\Xi _{ c c }^{++}\rightarrow D ^+ p K ^- \pi ^+ }$ candidates with the fit overlaid. The black points represent data, the continuous (green) line represents the combinatorial background and the two vertical parallel dashed (blue) lines define the region where the signal is expected. (right) The local p-value expressing the compatibility of the data with the background-only hypothesis. The horizontal dashed (red) lines indicate p-values of 1, 2 and 3$\sigma$ local significance. pub-Xi[..].pdf [20 KiB] HiDef png [246 KiB] Thumbnail [215 KiB] *.C file pub-Xi[..].pdf [18 KiB] HiDef png [337 KiB] Thumbnail [219 KiB] *.C file Invariant-mass distribution of the ${\Xi _{ c c }^{++}\rightarrow \Lambda _ c ^+ K ^- \pi ^+ \pi ^+ }$ candidates with the fit overlaid. The black points represent data, the dashed (green) line represents combinatorial background, the dotted (red) line represents the signal contribution and the continuous (blue) line is the total fit. pub-Lc[..].pdf [23 KiB] HiDef png [286 KiB] Thumbnail [243 KiB] *.C file The scores from the \texttt{CLs} method for each value of the assumed ratio of branching fractions $\mathcal{R}$. Observed values are shown by the solid black line. The set upper limits at 90% and 95% CL are indicated by the dotted (blue) line and the dashed (red) line, respectively. pub-Cls-R.pdf [16 KiB] HiDef png [123 KiB] Thumbnail [115 KiB] *.C file Animated gif made out of all figures. PAPER-2019-011.gif Thumbnail

Tables and captions

 Systematic and statistical uncertainties on the single-event sensitivity $\alpha_{s}$. Table_1.pdf [39 KiB] HiDef png [142 KiB] Thumbnail [60 KiB] tex code

Created on 08 August 2020.