CMS logoCMS event Hgg
Compact Muon Solenoid
LHC, CERN

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
Phys. Rev. D 110 (2024) 012002
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.
Figures & Tables Summary Additional Figures References CMS Publications
Figures

png pdf
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 $.

png pdf
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 $.

png pdf
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 $.

png pdf
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.

png pdf
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.

png pdf
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.

png pdf
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.

png pdf
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.

png pdf
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.

png pdf
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.

png pdf
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.

png pdf
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.

png pdf
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.

png pdf
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.

png pdf
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.

png pdf
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.

png pdf
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

png pdf
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.

png pdf
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.

png pdf
Table 3:
The measured efficiency ratios and their statistical uncertainties.

png pdf
Table 4:
Systematic uncertainties in percent in the ratio $ R $ from the different sources and the total uncertainty.

png pdf
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.

png pdf
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

png pdf
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.

png pdf
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.

png pdf
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.

png pdf
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.

png pdf
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.

png pdf
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.

png pdf
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.

png pdf
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.
References
1 D. Ebert, T. Feldmann, C. Kettner, and H. Reinhardt A diquark model for baryons containing one heavy quark Z. Phys. C 71 (1996) 329 hep-ph/9506298
2 D0 Collaboration Direct observation of the strange b baryon $ \Xi_{\text{b}}^- $ PRL 99 (2007) 052001 0706.1690
3 CDF Collaboration Observation and mass measurement of the baryon $ \Xi_{\text{b}}^- $ PRL 99 (2007) 052002 0707.0589
4 CDF Collaboration Observation of the $ \Xi_{\text{b}}^0 $ baryon PRL 107 (2011) 102001 1107.4015
5 CMS Collaboration Observation of a new $ \Xi_{\text{b}} $ baryon PRL 108 (2012) 252002 CMS-BPH-12-001
1204.5955
6 LHCb Collaboration Measurement of the properties of the $ \Xi_{\text{b}}^{*0} $ baryon JHEP 05 (2016) 161 1604.03896
7 LHCb Collaboration Observation of two new $ \Xi_{\text{b}}^- $ baryon resonances PRL 114 (2015) 062004 1411.4849
8 E. E. Jenkins Model-independent bottom baryon mass predictions in the 1 $ /N_c $ expansion PRD 77 (2008) 034012 0712.0406
9 M. Karliner, B. Keren-Zur, H. J. Lipkin, and J. L. Rosner The quark model and b baryons Ann. Phys. 324 (2009) 2 0804.1575
10 D. Ebert, R. N. Faustov, and V. O. Galkin Masses of excited heavy baryons in the relativistic quark model PLB 659 (2008) 612 0705.2957
11 LHCb Collaboration Observation of a new $ \Xi_{\text{b}}^- $ resonance PRL 121 (2018) 072002 1805.09418
12 LHCb Collaboration Observation of a new $ \Xi_{\text{b}}^0 $ state PRD 103 (2021) 012004 2010.14485
13 CMS Collaboration Observation of a new excited beauty strange baryon decaying to $ \Xi^-_\mathrm{b} \pi^+ \pi^- $ PRL 126 (2021) 252003 CMS-BPH-20-004
2102.04524
14 LHCb Collaboration Observation of two new excited $ \Xi_{\text{b}}^0 $ states decaying to $ \Lambda^0_{\text{b}} K^- \pi^+ $ PRL 128 (2022) 162001 2110.04497
15 LHCb Collaboration Observation of new baryons in the $ \Xi^-_\mathrm{b} \pi^+ \pi^- $ and $ \Xi^0_\mathrm{b} \pi^+ \pi^- $ systems PRL 131 (2023) 171901 2307.13399
16 W. Roberts and M. Pervin Heavy baryons in a quark model Int. J. Mod. Phys. A 23 (2008) 2817 0711.2492
17 D. Ebert, R. N. Faustov, and V. O. Galkin Spectroscopy and Regge trajectories of heavy baryons in the relativistic quark-diquark picture PRD 84 (2011) 014025 1105.0583
18 H. Garcilazo, J. Vijande, and A. Valcarce Faddeev study of heavy baryon spectroscopy JPG 34 (2007) 961 hep-ph/0703257
19 B. Chen, K.-W. Wei, and A. Zhang Assignments of $ \Lambda_Q $ and $ \Xi_Q $ baryons in the heavy quark-light diquark picture Eur. Phys. J. A 51 (2015) 82 1406.6561
20 I. L. Grach, I. M. Narodetskii, M. A. Trusov, and A. I. Veselov Heavy baryon spectroscopy in the QCD string model in Particles and Nuclei. Proceedings, 18th International Conference, PANIC08, Eilat, Israel, 2008 0811.2184
21 Q. Mao et al. QCD sum rule calculation for P-wave bottom baryons PRD 92 (2015) 114007 1510.05267
22 Z.-G. Wang Analysis of the $ {1/2^-} $ and $ {3/2^-} $ heavy and doubly heavy baryon states with QCD sum rules Eur. Phys. J. A 47 (2011) 81 1003.2838
23 K.-L. Wang, Y.-X. Yao, X.-H. Zhong, and Q. Zhao Strong and radiative decays of the low-lying $ S $- and $ P $-wave singly heavy baryons PRD 96 (2017) 116016 1709.04268
24 Y. Kawakami and M. Harada Singly heavy baryons with chiral partner structure in a three-flavor chiral model PRD 99 (2019) 094016 1902.06774
25 Z.-Y. Wang, J.-J. Qi, X.-H. Guo, and K.-W. Wei Spectra of charmed and bottom baryons with hyperfine interaction Chin. Phys. C 41 (2017) 093103 1701.04524
26 K. Thakkar, Z. Shah, A. K. Rai, and P. C. Vinodkumar Excited state mass spectra and Regge trajectories of bottom baryons Nucl. Phys. A 965 (2017) 57 1610.00411
27 K.-W. Wei et al. Spectroscopy of singly, doubly, and triply bottom baryons PRD 95 (2017) 116005 1609.02512
28 LHCb Collaboration Studies of beauty baryon decays to $ \text{D}^0 \text{p} \text{h}^- $ and $ \Lambda_{\text{c}}^+ \text{h}^- $ final states PRD 89 (2014) 032001 1311.4823
29 LHCb Collaboration Evidence for the strangeness-changing weak decay $ \Xi_{\text{b}}^-\to\Lambda_{\text{b}}^0\pi^- $ PRL 115 (2015) 241801 1510.03829
30 LHCb Collaboration Observation of the decay $ \Xi_{\text{b}}^- \to \text{p} K^-K^- $ PRL 118 (2017) 071801 1612.02244
31 LHCb Collaboration Observation of the $ \Xi_\mathrm{b}^-\to J/\psi\Lambda K^- $ decay PLB 772 (2017) 265 1701.05274
32 LHCb Collaboration Measurement of branching fractions of charmless four-body $ \Lambda_{\text{b}}^0 $ and $ \Xi_{\text{b}}^0 $ decays JHEP 02 (2018) 098 1711.05490
33 LHCb Collaboration Isospin amplitudes in $ \Lambda_{\text{b}}^0\to J/\psi \Lambda(\Sigma^0) $ and $ \Xi_{\text{b}}^0\to J/\psi \Xi^0(\Lambda) $ decays PRL 124 (2020) 111802 1912.02110
34 Particle Data Group Review of particle physics PTEP 2022 (2022) 083C01
35 LHCb Collaboration Evidence of a $ J/\psi\Lambda $ structure and observation of excited $ \Xi^- $ states in the $ \Xi^-_{\text{b}} \to J/\psi\Lambda K^- $ decay Sci. Bull. 66 (2021) 1278 2012.10380
36 LHCb Collaboration Search for $ CP $ violation in $ \Xi^-_{\text{b}} \to \text{p} \text{K}^- \text{K}^- $ decays PRD 104 (2021) 052010 2104.15074
37 A. G. Grozin Heavy quark effective theory Springer Berlin, Heidelberg, 2004
link
38 N. Isgur and M. B. Wise Spectroscopy with heavy quark symmetry PRL 66 (1991) 1130
39 M. A. Shifman and M. B. Voloshin Preasymptotic effects in inclusive weak decays of charmed particles Sov. J. Nucl. Phys. 41 (1985) 120
40 N. Isgur and M. B. Wise Weak decays of heavy mesons in the static quark approximation PLB 232 (1989) 113
41 I. I. Y. Bigi, N. G. Uraltsev, and A. I. Vainshtein Nonperturbative corrections to inclusive beauty and charm decays: QCD versus phenomenological models PLB 293 (1992) 430 hep-ph/9207214
42 CMS Collaboration Precision luminosity measurement in proton-proton collisions at $ \sqrt{s} = $ 13 TeV in 2015 and 2016 at CMS EPJC 81 (2021) 800 CMS-LUM-17-003
2104.01927
43 CMS Collaboration CMS luminosity measurement for the 2017 data-taking period at $ \sqrt{s} = $ 13 TeV CMS Physics Analysis Summary, 2018
CMS-PAS-LUM-17-004
CMS-PAS-LUM-17-004
44 CMS Collaboration CMS luminosity measurement for the 2018 data-taking period at $ \sqrt{s} = $ 13 TeV CMS Physics Analysis Summary, 2019
CMS-PAS-LUM-18-002
CMS-PAS-LUM-18-002
45 CMS Collaboration Measurement of B$ _\mathrm{c} $(2S)$ ^+ $ and B$ _\mathrm{c}^* $(2S)$ ^+ $ cross section ratios in proton-proton collisions at $ \sqrt{s}= $ 13 TeV PRD 102 (2020) 092007 CMS-BPH-19-001
2008.08629
46 CMS Collaboration HEPData record for this analysis link
47 CMS Collaboration The CMS experiment at the CERN LHC JINST 3 (2008) S08004
48 CMS Collaboration Development of the CMS detector for the CERN LHC Run 3 Accepted by JINST, 2023 CMS-PRF-21-001
2309.05466
49 CMS Collaboration Performance of the CMS muon detector and muon reconstruction with proton-proton collisions at $ \sqrt{s}= $ 13 TeV JINST 13 (2018) P06015 CMS-MUO-16-001
1804.04528
50 CMS Collaboration Description and performance of track and primary-vertex reconstruction with the CMS tracker JINST 9 (2014) P10009 CMS-TRK-11-001
1405.6569
51 CMS Tracker Group The CMS Phase-1 pixel detector upgrade JINST 16 (2021) P02027 2012.14304
52 CMS Collaboration Track impact parameter resolution for the full pseudorapidity coverage in the 2017 dataset with the CMS Phase-1 pixel detector CMS Detector Performance Note CMS-DP-2020-049, 2020
CDS
53 CMS Collaboration The CMS trigger system JINST 12 (2017) P01020 CMS-TRG-12-001
1609.02366
54 CMS Collaboration Performance of the CMS level-1 trigger in proton-proton collisions at $ \sqrt{s}= $ 13 TeV JINST 15 (2020) P10017 CMS-TRG-17-001
2006.10165
55 T. Sjöstrand et al. An introduction to PYTHIA 8.2 Comput. Phys. Commun. 191 (2015) 159 1410.3012
56 CMS Collaboration Extraction and validation of a new set of CMS PYTHIA8 tunes from underlying-event measurements EPJC 80 (2020) 4 CMS-GEN-17-001
1903.12179
57 D. J. Lange The EVTGEN particle decay simulation package NIM A 462 (2001) 152
58 E. Barberio, B. van Eijk, and Z. Was PHOTOS: A universal Monte Carlo for QED radiative corrections in decays Comput. Phys. Commun. 66 (1991) 115
59 E. Barberio and Z. Was PHOTOS: A universal Monte Carlo for QED radiative corrections. version 2.0 Comput. Phys. Commun. 79 (1994) 291
60 GEANT4 Collaboration GEANT 4 --- a simulation toolkit NIM A 506 (2003) 250
61 CMS Collaboration CMS tracking performance results from early LHC operation EPJC 70 (2010) 1165 CMS-TRK-10-001
1007.1988
62 CMS Collaboration Observation of two excited B$ ^+_\mathrm{c} $ states and measurement of the B$ ^+_\mathrm{c} $(2S) mass in pp collisions at $ \sqrt{s}= $ 13 TeV PRL 122 (2019) 132001 CMS-BPH-18-007
1902.00571
63 CMS Collaboration Study of excited $ \Lambda_\mathrm{b}^0 $ states decaying to $ \Lambda_\mathrm{b}^0\pi^+\pi^- $ in proton-proton collisions at $ \sqrt{s}= $ 13 TeV PLB 803 (2020) 135345 CMS-BPH-19-003
2001.06533
64 S. S. Wilks The large-sample distribution of the likelihood ratio for testing composite hypotheses Annals Math. Statist. 9 (1938) 60
65 G. Cowan, K. Cranmer, E. Gross, and O. Vitells Asymptotic formulae for likelihood-based tests of new physics EPJC 71 (2011) 1554 1007.1727
66 W. Detmold, C.-J. D. Lin, and S. Meinel Calculation of the heavy-hadron axial couplings $ g_1 $, $ g_2 $ and $ g_3 $ using lattice QCD PRD 85 (2012) 114508 1203.3378
67 C. Chen et al. Strong decays of charmed baryons PRD 75 (2007) 094017 0704.0075
68 S. Jackman Bayesian analysis for the social sciences John Wiley \& Sons, New Jersey, USA, 2009
link
69 CMS Collaboration Measurement of prompt open-charm production cross sections in proton-proton collisions at $ \sqrt{s}= $ 13 TeV JHEP 11 (2021) 225 CMS-BPH-18-003
2107.01476
70 J. M. Blatt and V. F. Weisskopf Theoretical nuclear physics Springer, New York, ISBN~978-0-471-08019-0, 1952
link
71 L. Lyons, D. Gibaut, and P. Clifford How to combine correlated estimates of a single physical quantity NIM A 270 (1988) 110
72 R. Nisius On the combination of correlated estimates of a physics observable EPJC 74 (2014) 3004 1402.4016
73 R. Nisius BLUE: combining correlated estimates of physics observables within ROOT using the best linear unbiased estimate method SoftwareX 11 (2020) 100468 2001.10310
74 T. Gutsche et al. Polarization effects in the cascade decay $ {\Lambda}_{\text{b}}\to\Lambda\mathbf{(}\to\text{p}{\pi}^{\mathbf{-}}\mathbf{)}\mathbf{+}J/\psi\mathbf{(}\to{\ell}^{\mathbf{+}}{\ell}^{\mathbf{-}}\mathbf{)} $ in the covariant confined quark model PRD 88 (2013) 114018 1309.7879
75 T. Gutsche et al. Towards an assessment of the ATLAS data on the branching ratio $ \Gamma(\Lambda_{\text{b}})\to\psi(2S)\Lambda^0 / \Gamma(\Lambda_{\text{b}})\to\text{J}/\psi\Lambda^0 $ PRD 92 (2015) 114008 1510.02266
76 Z.-T. Wei, H.-W. Ke, and X.-Q. Li Evaluating decay rates and asymmetries of $ \Lambda_{\text{b}} $ into light baryons in LFQM PRD 80 (2009) 094016 0909.0100
77 L. Mott and W. Roberts Rare dileptonic decays of $ \Lambda_{\text{b}} $ in a quark model Int. J. Mod. Phys. A 27 (2012) 1250016 1108.6129
Compact Muon Solenoid
LHC, CERN