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

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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 $\POmega _ c (X)^0$ 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 $\POmega _ c (X)^0$ arising from the $\Xi ^+_ c$ mass is given separately. Upper limits are also given for the resonances $\POmega _ c (3050)^0$ and $\POmega _ c (3119)^0$ for which the width is not significant. Table_1.pdf [53 KiB] HiDef png [95 KiB] Thumbnail [44 KiB] tex code

## 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 Fig1top.pdf [17 KiB] HiDef png [330 KiB] Thumbnail [316 KiB] *C file Fig2.pdf [46 KiB] HiDef png [814 KiB] Thumbnail [527 KiB] *C file Fig3.pdf [23 KiB] HiDef png [347 KiB] Thumbnail [384 KiB] *C file Fig4.pdf [61 KiB] HiDef png [407 KiB] Thumbnail [309 KiB] *C file Fig5.pdf [58 KiB] HiDef png [350 KiB] Thumbnail [258 KiB] *C file

Created on 20 February 2021.