Observation of five new narrow $\Omega_c^0$ states decaying to $\Xi^+_c K^-$

Information

LHCb-PAPER-2017-002
CERN-EP-2017-037
arXiv:1703.04639 [PDF]

(Submitted on 14 Mar 2017)
Phys. Rev. Lett. 118 (2017) 182001
Inspire 1517483

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Abstract

The $\Xi_c^+ K^-$ mass spectrum is studied with a sample of $pp$ collision data corresponding to an integrated luminosity of 3.3 fb$^{-1}$, collected by the LHCb experiment. The $\Xi_c^+$ is reconstructed in the decay mode $p K^- \pi^+$. Five new, narrow excited $\Omega_c^0$ states are observed: the $\Omega_c(3000)^0$, $\Omega_c(3050)^0$, $\Omega_c(3066)^0$, $\Omega_c(3090)^0$, and $\Omega_c(3119)^0$. Measurements of their masses and widths are reported.

Figures and captions

Distribution of the reconstructed invariant mass $m( p K ^- \pi ^+ )$ for all candidates in the inclusive $\Xi ^+_ c $ sample passing the likelihood ratio selection described in the text. The solid (red) curve shows the result of the fit, and the dashed (blue) line indicates the fitted background.	Fig1.pdf [17 KiB] HiDef png [194 KiB] Thumbnail [164 KiB] *.C file
Distribution of the reconstructed invariant mass $m(\Xi ^+_ c K ^- )$ for all candidates passing the likelihood ratio selection; the solid (red) curve shows the result of the fit, and the dashed (blue) line indicates the fitted background. The shaded (red) histogram shows the corresponding mass spectrum from the $\Xi ^+_ c $ sidebands and the shaded (light gray) distributions indicate the feed-down from partially reconstructed $\Omega _ c (X)^0$ resonances.	Fig2.pdf [60 KiB] HiDef png [374 KiB] Thumbnail [276 KiB] *.C file
Distribution of the reconstructed invariant mass $m(\Xi ^+_ c K ^- )$ for all candidates passing the likelihood ratio selection, shown as black points with error bars, and the wrong-sign $m(\Xi ^+_ c K ^+ )$ spectrum scaled by a factor of 0.95, shown as a solid (red) histogram.	Fig3.pdf [35 KiB] HiDef png [287 KiB] Thumbnail [235 KiB] *.C file
Animated gif made out of all figures.	PAPER-2017-002.gif Thumbnail

Tables and captions

Results of the fit to $m(\Xi ^+_ c K ^- )$ for the mass, width, yield and significance for each resonance. The subscript "${\rm fd}$" indicates the feed-down contributions described in the text. For each fitted parameter, the first uncertainty is statistical and the second systematic. The asymmetric uncertainty on the $\Omega _ c (X)^0$ arising from the $\Xi ^+_ c $ mass is given separately. Upper limits are also given for the resonances $\Omega _ c (3050)^0$ and $\Omega _ c (3119)^0$ for which the width is not significant.

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Supplementary Material [file]

Supplementary material full pdf	supple[..].pdf [344 KiB]
This ZIP file contains supplemetary material for the publication LHCb-PAPER-2017-002. The files are: supplementary.pdf : An overview of the extra figures .pdf, .png, .eps, .C : The figures in variuous formats	Fig1bot.pdf [17 KiB] HiDef png [294 KiB] Thumbnail [285 KiB] *C file
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