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| CMS-BPH-23-002 ; CERN-EP-2024-038 | ||
| Observation of the $ \Xi_{b}^{-}\to\psi{(2S)}\Xi^{-} $ decay and studies of the $ \Xi_{b}^{*0} $ baryon in proton-proton collisions at $ \sqrt{s} = $ 13 TeV | ||
| CMS Collaboration | ||
| 27 February 2024 | ||
| Submitted to Phys. Rev. D | ||
| Abstract: The first observation of the decay $ \Xi_{b}^{-}\to\psi{(2S)}\Xi^{-} $ and measurement of the branching ratio of $ \Xi_{b}^{-}\to\psi{(2S)}\Xi^{-} $ to $ \Xi_{b}^{-}\to\mathrm{J}/\psi\Xi^{-} $ are presented. The $ \mathrm{J}/\psi $ and $ \psi{(2S)} $ mesons are reconstructed using their dimuon decay modes. The results are based on proton-proton colliding beam data from the LHC collected by the CMS experiment at $ \sqrt{s} = $ 13 TeV in 2016-2018, corresponding to an integrated luminosity of 140 fb$ ^{-1} $. The branching fraction ratio is measured to be $ \mathcal{B} (\Xi_{b}^{-}\to\psi{(2S)}\Xi^{-}) / \mathcal{B} (\Xi_{b}^{-}\to\mathrm{J}/\psi\Xi^{-}) = $ 0.84 $ ^{+0.21}_{-0.19} $ (stat) $\pm$ 0.10 (syst) $\pm$ 0.02 ($ \mathcal{B} $), where the last uncertainty comes from the uncertainties in the branching fractions of the charmonium states. New measurements of the $ \Xi_{b}^{*0} $ baryon mass and natural width are also presented, using the $ \Xi_{b}^{-}\pi^{+} $ final state, where the $ \Xi_{b}^{-} $ baryon is reconstructed through the decays $ \mathrm{J}/\psi\Xi^{-} $, $ \psi{(2S)}\Xi^{-} $, $ \mathrm{J}/\psi\Lambda\mathrm{K^-} $, and $ \mathrm{J}/\psi\Sigma^{0}\mathrm{K^-} $. Finally, the fraction of the $ \Xi_{b}^{-} $ baryons produced from $ \Xi_{b}^{*0} $ decays is determined. | ||
| Links: e-print arXiv:2402.17738 [hep-ex] (PDF) ; CDS record ; inSPIRE record ; HepData record ; CADI line (restricted) ; | ||
| Figures & Tables | Summary | Additional Figures | References | CMS Publications |
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| Figures | |
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Figure 1:
The $ \Xi_{b}^{*0}\to\Xi_{b}^{-}\pi^{+} $ decay topology, where the $ \Xi_{b}^{-} $ baryon decays to $ \psi\Xi^{-} $ with $ \psi\to\mu^{+}\mu^{-} $ (upper) or $ \mathrm{J}/\psi\Lambda\mathrm{K^-} $ (lower), where $ \psi $ refers to the $ \mathrm{J}/\psi $ and $ \psi{(2S)} $ mesons. The distances given are the average decay lengths, $ c\tau $. |
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Figure 1-a:
The $ \Xi_{b}^{*0}\to\Xi_{b}^{-}\pi^{+} $ decay topology, where the $ \Xi_{b}^{-} $ baryon decays to $ \psi\Xi^{-} $ with $ \psi\to\mu^{+}\mu^{-} $ (upper) or $ \mathrm{J}/\psi\Lambda\mathrm{K^-} $ (lower), where $ \psi $ refers to the $ \mathrm{J}/\psi $ and $ \psi{(2S)} $ mesons. The distances given are the average decay lengths, $ c\tau $. |
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Figure 1-b:
The $ \Xi_{b}^{*0}\to\Xi_{b}^{-}\pi^{+} $ decay topology, where the $ \Xi_{b}^{-} $ baryon decays to $ \psi\Xi^{-} $ with $ \psi\to\mu^{+}\mu^{-} $ (upper) or $ \mathrm{J}/\psi\Lambda\mathrm{K^-} $ (lower), where $ \psi $ refers to the $ \mathrm{J}/\psi $ and $ \psi{(2S)} $ mesons. The distances given are the average decay lengths, $ c\tau $. |
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Figure 2:
Invariant mass distributions of the selected $ \mathrm{J}/\psi\Xi^{-} $ (upper left), $ \mathrm{J}/\psi\Lambda\mathrm{K^-} $ (upper right), and $ \psi{(2S)}\Xi^{-} $ [lower row, with $ \psi{(2S)}\to\mu^{+}\mu^{-} $ (left) and $ \psi{(2S)}\to\mathrm{J}/\psi\pi^{+}\pi^{-} $ (right) candidates]. The data are shown by the points, while the vertical bars represent the statistical uncertainties. The overall fit result is shown by the solid red curve, with the signal and background contributions given by the solid green and dashed blue curves, respectively. The vertical lines around each peak display the mass window required for a $ \Xi_{b}^{-} $ candidate to be used in the $ \Xi_{b}^{*0} $ studies. The dotted-dashed curve in the upper right plot shows the fitted contribution from the $ \Xi_{b}^{-}\to\mathrm{J}/\psi\Sigma^{0}\mathrm{K^-} $ decay, with the accompanying vertical dotted lines indicating the mass window for this mode. |
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Figure 2-a:
Invariant mass distributions of the selected $ \mathrm{J}/\psi\Xi^{-} $ (upper left), $ \mathrm{J}/\psi\Lambda\mathrm{K^-} $ (upper right), and $ \psi{(2S)}\Xi^{-} $ [lower row, with $ \psi{(2S)}\to\mu^{+}\mu^{-} $ (left) and $ \psi{(2S)}\to\mathrm{J}/\psi\pi^{+}\pi^{-} $ (right) candidates]. The data are shown by the points, while the vertical bars represent the statistical uncertainties. The overall fit result is shown by the solid red curve, with the signal and background contributions given by the solid green and dashed blue curves, respectively. The vertical lines around each peak display the mass window required for a $ \Xi_{b}^{-} $ candidate to be used in the $ \Xi_{b}^{*0} $ studies. The dotted-dashed curve in the upper right plot shows the fitted contribution from the $ \Xi_{b}^{-}\to\mathrm{J}/\psi\Sigma^{0}\mathrm{K^-} $ decay, with the accompanying vertical dotted lines indicating the mass window for this mode. |
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Figure 2-b:
Invariant mass distributions of the selected $ \mathrm{J}/\psi\Xi^{-} $ (upper left), $ \mathrm{J}/\psi\Lambda\mathrm{K^-} $ (upper right), and $ \psi{(2S)}\Xi^{-} $ [lower row, with $ \psi{(2S)}\to\mu^{+}\mu^{-} $ (left) and $ \psi{(2S)}\to\mathrm{J}/\psi\pi^{+}\pi^{-} $ (right) candidates]. The data are shown by the points, while the vertical bars represent the statistical uncertainties. The overall fit result is shown by the solid red curve, with the signal and background contributions given by the solid green and dashed blue curves, respectively. The vertical lines around each peak display the mass window required for a $ \Xi_{b}^{-} $ candidate to be used in the $ \Xi_{b}^{*0} $ studies. The dotted-dashed curve in the upper right plot shows the fitted contribution from the $ \Xi_{b}^{-}\to\mathrm{J}/\psi\Sigma^{0}\mathrm{K^-} $ decay, with the accompanying vertical dotted lines indicating the mass window for this mode. |
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Figure 2-c:
Invariant mass distributions of the selected $ \mathrm{J}/\psi\Xi^{-} $ (upper left), $ \mathrm{J}/\psi\Lambda\mathrm{K^-} $ (upper right), and $ \psi{(2S)}\Xi^{-} $ [lower row, with $ \psi{(2S)}\to\mu^{+}\mu^{-} $ (left) and $ \psi{(2S)}\to\mathrm{J}/\psi\pi^{+}\pi^{-} $ (right) candidates]. The data are shown by the points, while the vertical bars represent the statistical uncertainties. The overall fit result is shown by the solid red curve, with the signal and background contributions given by the solid green and dashed blue curves, respectively. The vertical lines around each peak display the mass window required for a $ \Xi_{b}^{-} $ candidate to be used in the $ \Xi_{b}^{*0} $ studies. The dotted-dashed curve in the upper right plot shows the fitted contribution from the $ \Xi_{b}^{-}\to\mathrm{J}/\psi\Sigma^{0}\mathrm{K^-} $ decay, with the accompanying vertical dotted lines indicating the mass window for this mode. |
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Figure 2-d:
Invariant mass distributions of the selected $ \mathrm{J}/\psi\Xi^{-} $ (upper left), $ \mathrm{J}/\psi\Lambda\mathrm{K^-} $ (upper right), and $ \psi{(2S)}\Xi^{-} $ [lower row, with $ \psi{(2S)}\to\mu^{+}\mu^{-} $ (left) and $ \psi{(2S)}\to\mathrm{J}/\psi\pi^{+}\pi^{-} $ (right) candidates]. The data are shown by the points, while the vertical bars represent the statistical uncertainties. The overall fit result is shown by the solid red curve, with the signal and background contributions given by the solid green and dashed blue curves, respectively. The vertical lines around each peak display the mass window required for a $ \Xi_{b}^{-} $ candidate to be used in the $ \Xi_{b}^{*0} $ studies. The dotted-dashed curve in the upper right plot shows the fitted contribution from the $ \Xi_{b}^{-}\to\mathrm{J}/\psi\Sigma^{0}\mathrm{K^-} $ decay, with the accompanying vertical dotted lines indicating the mass window for this mode. |
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Figure 3:
The mass difference $ \Delta M $ distribution of the selected $ \Xi_{b}^{-}\pi^{\pm} $ candidates for the decay channel labeled on each plot. The points show the correct-sign combinations and the blue bands the wrong-sign. The vertical bars on the points and the length of the bands represent the statistical uncertainties in each distribution, respectively. |
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Figure 3-a:
The mass difference $ \Delta M $ distribution of the selected $ \Xi_{b}^{-}\pi^{\pm} $ candidates for the decay channel labeled on each plot. The points show the correct-sign combinations and the blue bands the wrong-sign. The vertical bars on the points and the length of the bands represent the statistical uncertainties in each distribution, respectively. |
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Figure 3-b:
The mass difference $ \Delta M $ distribution of the selected $ \Xi_{b}^{-}\pi^{\pm} $ candidates for the decay channel labeled on each plot. The points show the correct-sign combinations and the blue bands the wrong-sign. The vertical bars on the points and the length of the bands represent the statistical uncertainties in each distribution, respectively. |
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Figure 3-c:
The mass difference $ \Delta M $ distribution of the selected $ \Xi_{b}^{-}\pi^{\pm} $ candidates for the decay channel labeled on each plot. The points show the correct-sign combinations and the blue bands the wrong-sign. The vertical bars on the points and the length of the bands represent the statistical uncertainties in each distribution, respectively. |
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Figure 3-d:
The mass difference $ \Delta M $ distribution of the selected $ \Xi_{b}^{-}\pi^{\pm} $ candidates for the decay channel labeled on each plot. The points show the correct-sign combinations and the blue bands the wrong-sign. The vertical bars on the points and the length of the bands represent the statistical uncertainties in each distribution, respectively. |
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Figure 4:
Results of the simultaneous fits to the $ \Delta M $ invariant mass distributions for the $ \Xi_{b}^{*0} $ candidates in the decay channels given in each plot. The points show the data, with the vertical bars representing the statistical uncertainty. The solid red curve displays the overall fit result, with the solid green and dashed blue curves showing the signal and background contributions, respectively. |
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Figure 4-a:
Results of the simultaneous fits to the $ \Delta M $ invariant mass distributions for the $ \Xi_{b}^{*0} $ candidates in the decay channels given in each plot. The points show the data, with the vertical bars representing the statistical uncertainty. The solid red curve displays the overall fit result, with the solid green and dashed blue curves showing the signal and background contributions, respectively. |
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Figure 4-b:
Results of the simultaneous fits to the $ \Delta M $ invariant mass distributions for the $ \Xi_{b}^{*0} $ candidates in the decay channels given in each plot. The points show the data, with the vertical bars representing the statistical uncertainty. The solid red curve displays the overall fit result, with the solid green and dashed blue curves showing the signal and background contributions, respectively. |
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Figure 4-c:
Results of the simultaneous fits to the $ \Delta M $ invariant mass distributions for the $ \Xi_{b}^{*0} $ candidates in the decay channels given in each plot. The points show the data, with the vertical bars representing the statistical uncertainty. The solid red curve displays the overall fit result, with the solid green and dashed blue curves showing the signal and background contributions, respectively. |
png pdf |
Figure 4-d:
Results of the simultaneous fits to the $ \Delta M $ invariant mass distributions for the $ \Xi_{b}^{*0} $ candidates in the decay channels given in each plot. The points show the data, with the vertical bars representing the statistical uncertainty. The solid red curve displays the overall fit result, with the solid green and dashed blue curves showing the signal and background contributions, respectively. |
| Tables | |
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Table 1:
The number of signal events $ N $, the mean $ \Xi_{b}^{-} $ mass $ m_{\Xi_{b}^{-}}^{\text{fit}} $, and the effective $ \Xi_{b}^{-} $ width $ \sigma_{\text{eff}} $ from the fits to the $ \Xi_{b}^{-} $ invariant mass distributions for each of the $ \Xi_{b}^{-} $ decay channels. The uncertainties are statistical only. |
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Table 2:
The fitted signal yields of the $ \Xi_{b}^{*0}\to\Xi_{b}^{-}\pi^{+} $ decay for each of the listed $ \Xi_{b}^{-} $ decay channels. Uncertainties are statistical only. |
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Table 3:
The measured efficiency ratios and their statistical uncertainties. |
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Table 4:
Systematic uncertainties in percent in the ratio $ R $ from the different sources and the total uncertainty. |
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Table 5:
Systematic uncertainties in percent in the ratio $ R_{\Xi_{b}^{*0}} $ from the different sources and the total uncertainty, separately for the $ \mathrm{J}/\psi\Xi^{-} $ and $ \mathrm{J}/\psi\Lambda\mathrm{K^-} $ decay modes. |
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Table 6:
The systematic uncertainties in MeVns in the measurement of the $ \Xi_{b}^{*0} $ mass difference and natural width from each of the sources, along with the total uncertainties. |
| Summary |
| In this article, we present the first observation of the $ \Xi_{b}^{-}\to\psi({2S})\Xi^{-} $ decay. We use data from LHC proton-proton (pp) collisions at $ \sqrt{s}= $ 13 TeV, collected by the CMS experiment during 2016--2018, corresponding to an integrated luminosity of 140 fb$ ^{-1} $. We measure the ratio of the branching fraction for the new decay to that for $ \Xi_{b}^{-}\to\mathrm{J}/\psi\Xi^{-} $ to be $R = \mathcal{B} (\Xi_{b}^{-}\to\psi({2S})\Xi^{-} )/ \mathcal{B} ( \Xi_{b}^{-}\to\mathrm{J}/\psi\Xi^{-} ) = $ 0.84 $^{+0.21}_{-0.19}$ (stat) $\pm$ 0.10 (syst) $\pm$ 0.02 ($\mathcal{B}$),where the last uncertainty comes from the uncertainties in the $ \mathrm{J}/\psi $ and $ \psi({2S}) $ branching fractions. This result is consistent with analogous measured ratios from $ {\mathrm{B}}_{(\mathrm{s})} $ and $ \Lambda_{b}^{0} $ decays such as $ {\mathrm{B}^{+}}\to\psi\mathrm{K^+} $, $ {\mathrm{B}^0}\to\psi\mathrm{K^0_S} $, $ \mathrm{B}_{s}^{0}\to\psi\phi $, and $ \Lambda_{b}^{0}\to\psi\Lambda $, whose values are in the range 0.5-0.6 [34] (here $ \psi $ refers to the $ \mathrm{J}/\psi $ and $ \psi({2S}) $ mesons). In general, currently existing results for such ratios do not form any clear and unambiguous pattern. New measurements, such as the one reported here, and corresponding theoretical predictions are required to build a robust model that can reliably describe b hardon decays to charmonium states. We reconstruct $ \Xi_{b}^{*0} $ candidates using the $ \Xi_{b}^{*0}\to\Xi_{b}^{-}\pi^{+} $ decay mode by combining tracks from the proton-proton collision vertex with $ \Xi_{b}^{-} $ candidates from four different decay modes. A simultaneous fit of all decay modes is used to extract the mass difference and natural width, which are consistent with our previous results [5], but with much better precision. They are also in agreement with the LHCb measurements [6,15]. Using the world-average value for the $ \Xi_{b}^{-} $ baryon mass [34], we measure the mass of the $ \Xi_{b}^{*0} $ baryon to be $ M( \Xi_{b}^{*0} ) = $ 5952.4 $\pm$ 0.1 (stat+syst) $\pm$ 0.6 ($m_{ \Xi_{b}^{-} }$) MeV, where the last uncertainty comes from the uncertainty in the $ \Xi_{b}^{-} $ baryon mass. We measure the natural width to be $ \Gamma(\Xi_{b}^{*0}) = $ 0.87 $ ^{+0.22}_{-0.20} $ (stat) $\pm$ 0.16 (syst) MeV. Finally, our determination of the $ \Xi_{b}^{*0} $ / $ \Xi_{b}^{-} $ relative production rate $ R_{\Xi_{b}^{*0}} = $ 0.23 $ \pm $ 0.04 (stat) $ \pm $ 0.02 (syst) is in good agreement with the LHCb result [6] of 0.28 $ \pm $ 0.03 $ \pm $ 0.01 and is of a similar precision. From the measured values of this ratio, we conclude that about 1/4 of $ \Xi_{b}^{-} $ baryons are produced from the $ \Xi_{b}^{*0}\to\Xi_{b}^{-}\pi^{+} $ decay. The other major $ \Xi_{b}^{*0} $ decay is $ \Xi_{b}^{*0}\to\Xi_{b}^{0}\pi^{0} $. Since $ \mathcal{B}(\Xi_{b}^{*}\to\Xi_{b}\pi) $ should be close to 100%, we expect $ \mathcal{B}(\Xi_{b}^{*0}\to\Xi_{b}^{-}\pi^{+}) \approx $ 2 $\mathcal{B}(\Xi_{b}^{*0}\to\Xi_{b}^{0}\pi^{0}) \approx $ 2/3, where the factor of 2 comes from isospin differences and the Clebsch--Gordan coefficients [34]. Incorporating this estimate of $ \mathcal{B}(\Xi_{b}^{*0}\to\Xi_{b}^{-}\pi^{+}) $ into our results for the ratio of production cross sections, we find that $ \sigma(\mathrm{p}\mathrm{p}\to\Xi_{b}^{*0} X) / \sigma(\mathrm{p}\mathrm{p}\to\Xi_{b}^{-} X) \approx $ 1/3. If the relative production rate for $ \Xi_{b}^{*-} $ to $ \Xi_{b}^{-} $ follows the same scheme, the corresponding ratio can be estimated as $ R_{\Xi_{b}^{*-}} = [\sigma(\mathrm{p}\mathrm{p}\to\Xi_{b}^{*-} X) \mathcal{B}(\Xi_{b}^{*-}\to\Xi_{b}^{-}\pi^{0})] / \sigma(\mathrm{p}\mathrm{p}\to\Xi_{b}^{-} X) \approx $ 1/3 $\times$ 1/3 $=$ 1/9. Thus, we can conclude that about a third of the $ \Xi_{b}^{-} $ baryons are produced from $ \Xi_{b}^{*} $ decays. Since decays from higher-mass excited $ \Xi_{b} $ baryons are also possible, such as the $ \Xi_{b}(6227) $ doublet reported by the LHCb experiment [11,12], less than two thirds of the $ \Xi_{b}^{-} $ baryons are expected to be directly produced from pp collisions. It is clear that further studies of different ground- and excited-state $ \Xi_{b} $ baryons are needed to fully understand this family of baryons. |
| Additional Figures | |
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Additional Figure 1:
Comparison of the branching fractions ratios $ \mathcal{B}(\mathrm{H}_\mathrm{b} \to \psi{(2S)} \mathrm{h}) / \mathcal{B}(\mathrm{H}_\mathrm{b} \to \mathrm{J}/\psi \mathrm{h}) $ for $ {\mathrm{B}^{+}} $, $ {\mathrm{B}^0} $, $ \mathrm{B}_{s}^{0} $, $ \mathrm{B}_{c}^{+} $, $ \Lambda_{b}^{0} $, and $ \Xi_{b}^{-} $ decays. The black dotes represents the known values from the PDG [34], blue bar corresponds to the theoretical predictions from Refs [74,75,76,77], and this paper's result by CMS is highlighted in red. |
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Additional Figure 2:
Invariant mass distributions of the selected $ \mathrm{J}/\psi\Xi^{-} $ (upper left), $ \psi{(2S)} \Xi^{-} $ with $ \psi{(2S)} \to\mu^{+}\mu^{-} $ (upper right), and $ \mathrm{J}/\psi\Lambda\mathrm{K^-} $ (lower) candidates with a single HLT path required, as described in the paper's text. The fit results are overlaid, and the signal yields are 103 $ \,^{+14}_{-13} $, 38 $ \,^{+8}_{-7} $, and 606 $ \,^{+67}_{-64} $ for the $ \Xi_{b}^{-}\to\mathrm{J}/\psi\Xi^{-} $, $ \Xi_{b}^{-}\to \psi{(2S)} \Xi^{-} $, and $ \Xi_{b}^{-}\to\mathrm{J}/\psi\Lambda\mathrm{K^-} $ modes, respectively. |
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Additional Figure 2-a:
Invariant mass distributions of the selected $ \mathrm{J}/\psi\Xi^{-} $ candidates with a single HLT path required, as described in the paper's text. The fit results are overlaid, and the signal yields are 103 $ \,^{+14}_{-13} $, 38 $ \,^{+8}_{-7} $, and 606 $ \,^{+67}_{-64} $ for the $ \Xi_{b}^{-}\to\mathrm{J}/\psi\Xi^{-} $, $ \Xi_{b}^{-}\to \psi{(2S)} \Xi^{-} $, and $ \Xi_{b}^{-}\to\mathrm{J}/\psi\Lambda\mathrm{K^-} $ modes, respectively. |
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Additional Figure 2-b:
Invariant mass distributions of the selected $ \psi{(2S)} \Xi^{-} $ with $ \psi{(2S)} \to\mu^{+}\mu^{-} $ candidates with a single HLT path required, as described in the paper's text. The fit results are overlaid, and the signal yields are 103 $ \,^{+14}_{-13} $, 38 $ \,^{+8}_{-7} $, and 606 $ \,^{+67}_{-64} $ for the $ \Xi_{b}^{-}\to\mathrm{J}/\psi\Xi^{-} $, $ \Xi_{b}^{-}\to \psi{(2S)} \Xi^{-} $, and $ \Xi_{b}^{-}\to\mathrm{J}/\psi\Lambda\mathrm{K^-} $ modes, respectively. |
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Additional Figure 2-c:
Invariant mass distributions of the selected $ \mathrm{J}/\psi\Lambda\mathrm{K^-} $ candidates with a single HLT path required, as described in the paper's text. The fit results are overlaid, and the signal yields are 103 $ \,^{+14}_{-13} $, 38 $ \,^{+8}_{-7} $, and 606 $ \,^{+67}_{-64} $ for the $ \Xi_{b}^{-}\to\mathrm{J}/\psi\Xi^{-} $, $ \Xi_{b}^{-}\to \psi{(2S)} \Xi^{-} $, and $ \Xi_{b}^{-}\to\mathrm{J}/\psi\Lambda\mathrm{K^-} $ modes, respectively. |
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Additional Figure 3:
The mass difference $ \Delta M $ distribution of the selected $ \Xi_{b}^{-}\pi^{+} $ candidates, with the $ \Xi_{b}^{-} $ decays to $ \mathrm{J}/\psi\Xi^{-} $ (left) and $ \mathrm{J}/\psi\Lambda\mathrm{K^-} $ (right), with a single HLT path required, as described in the paper's text. The fit results are overlaid, and the yields of $ \Xi_{b}^{*0} $ signal are 13 $ \pm $ 4 and 74 $ \pm $ 11 for the $ \Xi_{b}^{-}\to\mathrm{J}/\psi\Xi^{-} $ and $ \Xi_{b}^{-}\to\mathrm{J}/\psi\Lambda\mathrm{K^-} $ modes, respectively. |
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Additional Figure 3-a:
The mass difference $ \Delta M $ distribution of the selected $ \Xi_{b}^{-}\pi^{+} $ candidates, with the $ \Xi_{b}^{-} $ decays to $ \mathrm{J}/\psi\Xi^{-} $, with a single HLT path required, as described in the paper's text. The fit results are overlaid, and the yields of $ \Xi_{b}^{*0} $ signal are 13 $ \pm $ 4 and 74 $ \pm $ 11 for the $ \Xi_{b}^{-}\to\mathrm{J}/\psi\Xi^{-} $ and $ \Xi_{b}^{-}\to\mathrm{J}/\psi\Lambda\mathrm{K^-} $ modes, respectively. |
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Additional Figure 3-b:
The mass difference $ \Delta M $ distribution of the selected $ \Xi_{b}^{-}\pi^{+} $ candidates, with the $ \Xi_{b}^{-} $ decays to $ \mathrm{J}/\psi\Lambda\mathrm{K^-} $, with a single HLT path required, as described in the paper's text. The fit results are overlaid, and the yields of $ \Xi_{b}^{*0} $ signal are 13 $ \pm $ 4 and 74 $ \pm $ 11 for the $ \Xi_{b}^{-}\to\mathrm{J}/\psi\Xi^{-} $ and $ \Xi_{b}^{-}\to\mathrm{J}/\psi\Lambda\mathrm{K^-} $ modes, respectively. |
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