#CMSpaper: Measurement of B meson production fraction ratios in proton-proton collisions at √s = 13 TeV using open-charm and charmonium decays (arXiv:2602.10270)
https://arxiv.org/abs/2602.10270 #BPhysics 
Measurement of B meson production fraction ratios in proton-proton collisions at $\sqrt{s}$ = 13 TeV using open-charm and charmonium decays
Production fraction ratios of B$^+$, B$^0$, and B$^0_\mathrm{s}$ mesons are measured in proton-proton collisions at $\sqrt{s}$ = 13 TeV using a special data set recorded in 2018 with high-rate triggers designed to collect an unbiased sample of $10^{10}$ b hadrons with the CMS experiment at the LHC. These data allow the use of the open-charm decays of B mesons (B$_\mathrm{(s)}$ $\to$ $π$D$_\mathrm{(s)}$) where the D meson decays into fully hadronic final states. Production fraction ratios as functions of B meson transverse momentum ($p_\mathrm{T}$) and rapidity ($y$) are measured using the open-charm decays in the kinematic range of 8 $\lt$ $p_\mathrm{T}$ $\lt$ 60 GeV and $\lvert y \rvert$ $\lt$ 2.25. In addition, the same data are used to measure the relative production fraction ratios with the charmonium decay channels (B$_\mathrm{(s)}$ $\to$ X$\,$J/$ψ$ with X indicating a K$^+$, K$^*$(892)$^0$, or $ϕ$(1020) meson) with the J/$ψ$ meson decaying into a pair of muons. By utilizing known branching fractions, precision theoretical calculations, and the open-charm results, the production fraction ratios in the charmonium samples are determined with an absolute normalization for the first time. These results also improve several world-average values of the ratios of branching fractions of B meson decays to charmonium and open-charm states. Finally, we test isospin invariance in B meson production in proton-proton collisions and observe that it holds within the experimental precision.
#CMSpaper soon on arXiv: Measurement of B meson production fraction ratios in proton-proton collisions at √s = 13 TeV using open-charm and charmonium decays (CERN-EP-2025-176)
https://cds.cern.ch/record/2954592 #BPhysics Measurement of $ {\mathrm{B}} $ meson production fraction ratios in proton-proton collisions at $ \sqrt{s} = $ 13 TeV using open-charm and charmonium decays
Production fraction ratios of $ {\mathrm{B}^{+}} $, $ {\mathrm{B}^0} $, and $ \mathrm{B}_{s}^{0} $ mesons are measured in proton-proton collisions at $ \sqrt{s} = $ 13 TeV using a special data set recorded in 2018 with high-rate triggers designed to collect an unbiased sample of $ 10^{10} \mathrm{b} $ hadrons with the CMS experiment at the LHC\@. These data allow the use of the open-charm decays of $ {\mathrm{B}} $ mesons ($ {\mathrm{B}}_{(\mathrm{s})} \!\to\! \pi\mathrm{D}_{(\mathrm{s})} $) where the $ \mathrm{D} $ meson decays into fully hadronic final states. Production fraction ratios as functions of $ {\mathrm{B}} $ meson transverse momentum ($ p_{\mathrm{T}} $) and rapidity ($ y $) are measured using the open-charm decays in the kinematic range of 8 $ < p_{\mathrm{T}} < $ 60 GeV and $ |y| < $ 2.25. In addition, the same data are used to measure the relative production fraction ratios with the charmonium decay channels ($ {\mathrm{B}}_{(\mathrm{s})} \!\to\! \mathrm{X}{\mathrm{J}/\psi} $ with $ \mathrm{X} $ indicating a $ \mathrm{K^+} $, $ \mathrm{K^*}(892)^0 $, or $ \phi(1020) $ meson) with the $ {\mathrm{J}/\psi} $ meson decaying into a pair of muons. By utilizing known branching fractions, precision theoretical calculations, and the open-charm results, the production fraction ratios in the charmonium samples are determined with an absolute normalization for the first time. These results also improve several world-average values of the ratios of branching fractions of $ {\mathrm{B}} $ meson decays to charmonium and open-charm states. Finally, we test isospin invariance in $ {\mathrm{B}} $ meson production in proton-proton collisions and observe that it holds within the experimental precision.
#CMSpaper: Observation of Υ(1S) + Z associated production and measurement of the effective double-parton scattering cross section in proton-proton collisions at √s = 13 TeV (arXiv:2602.02770)
https://arxiv.org/abs/2602.02770 #BPhysics 
Observation of $Υ$(1S) + Z associated production and measurement of the effective double-parton scattering cross section in proton-proton collisions at $\sqrt{s}$ = 13 TeV
The observation of associated production of an $Υ$(1S) meson with a Z boson and a measurement of the ratio of its fiducial cross section to the fiducial cross section of the Z boson are presented. Both the $Υ$(1S) meson and the Z boson are identified via decays into a pair of opposite-sign muons. The analysis is based on proton-proton (pp) collision data at $\sqrt{s}$ = 13 TeV, collected with the CMS detector in 2016$-$2018 and corresponding to an integrated luminosity of 138 fb$^{-1}$. Using the production of the Z boson decaying into four muons as a normalization channel, the ratio of the fiducial cross sections $σ$(pp $\to$ Z $+$ $Υ$(1S))$\mathcal{B}$(Z $\to$ $μ^+μ^-$)$\mathcal{B}$($Υ$(1S) $\to$ $μ^+μ^-$ ) to $σ$(pp $\to$ Z)$\mathcal{B}$(Z $\to$ 4$μ$) is measured to be $\mathcal{R}_{\mathrm{Z+Υ}\mathrm{(1S)}}$ = (21.1 $\pm$ 55 (stat) $\pm$ 0.6 (syst) $\times$ 10$^{-3}$), where stat and syst denote the statistical and systematic uncertainties, respectively. The result is used to extract the effective double-parton scattering cross section $σ_\text{eff}$ = 13.0$^{+7.7}_{-3.4}$. In addition, for the first time, $σ_\text{eff}$ is measured in bins of the transverse momentum of the $Υ$(1S) meson or of the Z boson.
#CMSpaper soon on arXiv: Observation of Υ(1S) + Z associated production and measurement of the effective double-parton scattering cross section in proton-proton collisions at √s = 13 TeV (CERN-EP-2025-163)
https://cds.cern.ch/record/2954080 #BPhysics Observation of $ \Upsilon\mathrm{(1S)} $ + Z associated production and measurement of the effective double-parton scattering cross section in proton-proton collisions at $ \sqrt{s}= $ 13 TeV
The observation of associated production of an $ \Upsilon\mathrm{(1S)} $ meson with a Z boson and a measurement of the ratio of its fiducial cross section to the fiducial cross section of the Z boson are presented. Both the $ \Upsilon\mathrm{(1S)} $ meson and the Z boson are identified via decays into a pair of opposite-sign muons. The analysis is based on proton-proton (pp) collision data at $ \sqrt{s}= $ 13 TeV, collected with the CMS detector in 2016--2018 and corresponding to an integrated luminosity of 138 fb$ ^{-1} $. Using the production of the Z boson decaying into four muons as a normalization channel, the ratio of the fiducial cross sections $ \sigma(\mathrm{p}\mathrm{p}\to\mathrm{Z}+\Upsilon\mathrm{(1S)}) \mathcal{B}(\mathrm{Z}\to\mu^{+}\mu^{-}) \mathcal{B}(\Upsilon\mathrm{(1S)}\to\mu^{+}\mu^{-}) $ to $ \sigma(\mathrm{p}\mathrm{p}\to\mathrm{Z})\mathcal{B}(\mathrm{Z}\to4\mu) $ is measured to be $ \mathcal{R}_{\mathrm{Z}+ \Upsilon\mathrm{(1S)}}=( $ 21.1 $ \pm $ 5.5 (stat) $ \pm $ 0.6 (syst) $) \times 10^{-3} $, where stat and syst denote the statistical and systematic uncertainties, respectively. The result is used to extract the effective double-parton scattering cross section $ \sigma_\text{eff} = $ 13.0 $ ^{+7.7}_{-3.4} $ $ $ mb. In addition, for the first time, $ \sigma_\text{eff} $ is measured in bins of the transverse momentum of the $ \Upsilon\mathrm{(1S)} $ meson or of the Z boson.
#CMSpaper: Observation of a family of all-charm tetraquarks (arXiv:2602.02252)
https://arxiv.org/abs/2602.02252 #BPhysics 
Observation of a family of all-charm tetraquarks
Three structures, X(6600), X(6900), and X(7100), have emerged from the J$/ψ\,$J$/ψ$ (J$/ψ$ $\to$ $μ^+μ^-$) mass spectrum. These are candidates of all-charm tetraquarks, an exotic form of hadronic matter. A clearer picture of these states is obtained using proton-proton collision data collected by the CMS detector that corresponds to 315 fb$^{-1}$, which yields 3.6 times more J$/ψ\,$J$/ψ$ pairs than previous studies by CMS. All three structures, and their mutual interference, have statistical significances above five standard deviations. The presence of interference implies that the structures have common quantum numbers. Their squared masses align linearly with a resonance index and have natural widths that systematically decrease as the index increases. These features are consistent with radial excitations of tetraquarks composed of two aligned spin-1 diquarks without orbital excitation, and disfavor other interpretations. The J$/ψ\,$$ψ$(2S) $\to$ $μ^+μ^-μ^+μ^-$ decay mode is also explored and the X(6900) and X(7100) states are found with significances exceeding 8 and 4 standard deviations, respectively.
#CMSpaper soon on arXiv: Observation of a family of all-charm tetraquarks (CERN-EP-2025-248)
https://cds.cern.ch/record/2953986 #BPhysics Observation of a family of all-charm tetraquarks
Three structures, $\mathrm{X} (6600)$, $\mathrm{X} (6900)$, and $\mathrm{X} (7100)$, have emerged from the $ \mathrm{J}/\psi \mathrm{J}/\psi $ ($ \mathrm{J}/\psi \to \mu^{+}\mu^{-} $) mass spectrum. These are candidates of all-charm tetraquarks, an exotic form of hadronic matter. A clearer picture of these states is obtained using proton-proton collision data collected by the CMS detector that corresponds to 315 fb$ ^{-1} $, which yields 3.6 times more $ \mathrm{J}/\psi \mathrm{J}/\psi $ pairs than previous studies by CMS. All three structures, and their mutual interference, have statistical significances above five standard deviations. The presence of interference implies that the structures have common quantum numbers. Their squared masses align linearly with a resonance index and have natural widths that systematically decrease as the index increases. These features are consistent with radial excitations of tetraquarks composed of two aligned spin-1 diquarks without orbital excitation, and disfavor other interpretations. The $ \mathrm{J}/\psi (\mathrm{2S}) \to \mu^{+}\mu^{-}\mu^{+}\mu^{-} $ decay mode is also explored and the $\mathrm{X} (6900)$ and $\mathrm{X} (7100)$ states are found with significances exceeding 8 and 4 standard deviations, respectively.
#CMSpaper: Measurement of the Υ(1S), Υ(2S), and Υ(3S) differential cross sections in pp collisions at √s = 13.6 TeV (arXiv:2601.20023)
https://arxiv.org/abs/2601.20023 #BPhysics 
Measurement of the $Υ$(1S), $Υ$(2S), and $Υ$(3S) differential cross sections in pp collisions at $\sqrt{s}$ = 13.6 TeV
The production cross sections of the $Υ$(1S), $Υ$(2S), and $Υ$(3S) mesons are measured in proton-proton collisions at $\sqrt{s}$ = 13.6 TeV, using a data sample collected in 2022 by the CMS experiment and corresponding to an integrated luminosity of 37.4 fb$^{-1}$. The measurement is performed in the $μ^+μ^-$ decay channels, differentially as a function of transverse momentum in the 20$-$200 GeV range, in the $\lvert y\rvert$ $\lt$ 0.6 and 0.6 $\lt$ $\lvert y\rvert$ $\lt$ 1.2 rapidity intervals.
#CMSpaper soon on arXiv: Measurement of the Υ(1S), Υ(2S), and Υ(3S) differential cross sections in pp collisions at √s = 13.6 TeV (CERN-EP-2026-004)
https://cds.cern.ch/record/2953566 #BPhysics Measurement of the $ \Upsilon{\textrm{(1S)}} $, $ \Upsilon{\textrm{(2S)}} $, and $ \Upsilon{\textrm{(3S)}} $ differential cross sections in pp collisions at $ \sqrt{s} = $ 13.6 TeV
The production cross sections of the $ \Upsilon{\textrm{(1S)}} $, $ \Upsilon{\textrm{(2S)}} $, and $ \Upsilon{\textrm{(3S)}} $ mesons are measured in proton-proton collisions at $ \sqrt{s}= $ 13.6 TeV, using a data sample collected in 2022 by the CMS experiment and corresponding to an integrated luminosity of 37.4 fb$ ^{-1} $. The measurement is performed in the $ \mu^{+}\mu^{-} $ decay channels, differentially as a function of transverse momentum in the 20-200 GeV range, in the $ |y| < $ 0.6 and 0.6 $ < |y| < $ 1.2 rapidity intervals.
#CMSPAS: Observation of the Rare Decay of the Eta Meson to a Muon Pair and an Electron Pair (CMS-PAS-BPH-24-001)
https://cds.cern.ch/record/2951499 #BPhysics #CMSPAS: Measurement of the Upsilon(1S), Upsilon(2S), and Upsilon(3S) differential production cross sections in pp collisions at 13.6 TeV (CMS-PAS-BPH-24-004)
https://cds.cern.ch/record/2948877 #BPhysics 
Measurement of the Upsilon(1S), Upsilon(2S), and Upsilon(3S) differential production cross sections in pp collisions at 13.6 TeV
The production cross sections of the $\Upsilon$(1S), $\Upsilon$(2S), and $\Upsilon$(3S) mesons are measured in proton-proton collisions at $\sqrt{s}=13.6$ TeV, using a data sample collected in 2022 by the CMS experiment and corresponding to an integrated luminosity of 37.4 $\text{fb}^{-1}$. The measurement is performed in the dimuon decay channels, differentially as a function of transverse momentum in the 20$-$200 GeV range, in the $|y| < 0.6$ and $0.6 < |y| < 1.2$ rapidity intervals.
CMS Publications