The first observation of the decay $\Xi^-_\mathrm{b}$$\to$$\psi$(2S)$\Xi^-$ and measurement of the branching ratio of $\Xi^-_\mathrm{b}$$\to$$\psi$(2S)$\Xi^-$ to $\Xi^-_\mathrm{b}$$\to$ J/$\psi$$\Xi^-$ are presented. The 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^-_\mathrm{b}$$\to$$\psi$(2S)$\Xi^-$)/$\mathcal{B}$($\Xi^-_\mathrm{b}$$\to$ J/$\psi$$\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 $\Xi_\mathrm{b}^{\ast{}0}$ baryon mass and natural width are also presented, using the $\Xi_\mathrm{b}^-\pi^+$ final state, where the $\Xi^-_\mathrm{b}$ baryon is reconstructed through the decays J/$\psi \Xi^-$, $\psi$(2S)$\Xi^-$, J/$\psi \Lambda$K$^-$, and J/$\psi \Sigma^0$K$^-$. Finally, the fraction of the $\Xi^-_\mathrm{b}$ baryons produced from $\Xi_\mathrm{b}^{\ast{}0}$ decays is determined.
The measured ratio of branching fractions
Measured mass
Measured mass difference
Using proton-proton collision data corresponding to an integrated luminosity of 140 fb$^{-1}$ collected by the CMS experiment at $\sqrt{s}$ = 13 TeV, the $\Lambda_\text{b}^0$$\to$ J/$\psi\Xi^-$K$^+$ decay is observed for the first time, with a statistical significance exceeding 5 standard deviations. The relative branching fraction, with respect to the $\Lambda_\text{b}^0$$\to$$\psi$(2S)$\Lambda$ decay, is measured to be $\mathcal{B}$($\Lambda_\text{b}^0$$\to$ J/$\psi\Xi^-$K$^+$)/$\mathcal{B}$( $\Lambda_\text{b}^0$$\to$$\psi$(2S)$\Lambda$) = [3.38 $\pm$ 1.02 $\pm$ 0.61 $\pm$ 0.03]%, where the first uncertainty is statistical, the second is systematic, and the third is related to the uncertainties in $\mathcal{B}$($\psi$(2S) $\to$ J/$\psi\pi^+\pi^-$) and $\mathcal{B}$($\Xi^-$ $\to$ $\Lambda\pi^-$).
The measured branching fraction ratio
A test of lepton flavor universality in B$^{\pm}$$\to$ K$^{\pm}\mu^+\mu^-$ and B$^{\pm}$$\to$ K$^{\pm}$e$^+$e$^-$ decays, as well as a measurement of differential and integrated branching fractions of a nonresonant B$^{\pm}$$\to$ K$^{\pm}\mu^+\mu^-$ decay are presented. The analysis is made possible by a dedicated data set of proton-proton collisions at $\sqrt{s}$ = 13 TeV recorded in 2018, by the CMS experiment at the LHC, using a special high-rate data stream designed for collecting about 10 billion unbiased b hadron decays. The ratio of the branching fractions $\mathcal{B}$(B$^{\pm}$$\to$ K$^{\pm}\mu^+\mu^-$) to $\mathcal{B}$(B$^{\pm}$$\to$ K$^{\pm}$e$^+$e$^-$) is determined from the measured double ratio $R$(K) of these decays to the respective branching fractions of the B$^\pm$$\to$ J/$\psi$K$^\pm$ with J/$\psi$$\to$$\mu^+\mu^-$ and e$^+$e$^-$ decays, which allow for significant cancellation of systematic uncertainties. The ratio $R$(K) is measured in the range 1.1 $\lt q^2 \lt$ 6.0 GeV$^2$, where $q$ is the invariant mass of the lepton pair, and is found to be $R$(K) = 0.78$^{+0.47}_{-0.23}$, in agreement with the standard model expectation $R$(K) $\approx$ 1. This measurement is limited by the statistical precision of the electron channel. The integrated branching fraction in the same $q^2$ range, $\mathcal{B}$(B$^{\pm}$$\to$ K$^{\pm}\mu^+\mu^-$) = (12.42 $\pm$ 0.68) $\times$ 10$^{-8}$, is consistent with the present world-average value and has a comparable precision.
The differential $\text{B}^+ \to \text{K}^+\mu^+\mu^-$ branching fraction measured in the individual $q^2$ bins. The uncertainties in the yields are statistical uncertainties from the fit, while the branching fraction uncertainties include both the statistical and systematic components.
Differential branching fraction $d\mathcal{B}/dq^2$, with theoretical predictions obtained with the HEPFiT, SuperIso, Flavio, and EOS packages. The HEPFiT predictions are available only for $q^2 < 8\ \mathrm{GeV}^2$.
Relative uncertainties in the differential branching fraction measurement of $\mathrm{B}^+\to\mathrm{K}^+\mu^+\mu^-$ per $q^2$ bin.
A search for the lepton flavor violating $\tau$$\to$ 3$\mu$ decay is performed using proton-proton collision events at a center-of-mass energy of 13 TeV collected by the CMS experiment at the LHC in 2017-2018, corresponding to an integrated luminosity of 97.7 fb$^{-1}$. Tau leptons produced in both heavy-flavor hadron and W boson decays are exploited in the analysis. No evidence for the decay is observed. The results of this search are combined with an earlier null result based on data collected in 2016 to obtain a total integrated luminosity of 131 fb$^{-1}$. The observed (expected) upper limits on the branching fraction $\mathcal{B}$($\tau$$\to$ 3$\mu$) at confidence levels of 90 and 95% are 2.9 $\times$ 10$^{-8}$ (2.4 $\times$ 10$^{-8}$) and 3.6 $\times$ 10$^{-8}$ (3.0 $\times$ 10$^{-8}$), respectively.
Expected and observed upper limits on the $\tau\to3\mu$ branching fraction at 90% of confidence level for different categories of the analyis.
Expected and observed upper limits on the $\tau\to3\mu$ branching fraction at 95% of confidence level for the Run2 combination.
The dependence of the ratio between the B$_\mathrm{s}^0$ and B$^+$ hadron production fractions, $f_\mathrm{s} / f_\mathrm{u}$, on the transverse momentum ($p_\mathrm{T}$) and rapidity of the B mesons is studied using the decay channels B$_\mathrm{s}^0$$\to$ J$/\psi\,\phi$ and B$^+$$\to$ J$/\psi$ K$^+$. The analysis uses a data sample of proton-proton collisions at a center-of-mass energy of 13 TeV, collected by the CMS experiment in 2018 and corresponding to an integrated luminosity of 61.6 fb$^{-1}$. The $f_\mathrm{s} / f_\mathrm{u}$ ratio is observed to depend on the B $p_\mathrm{T}$ and to be consistent with becoming asymptotically constant at large $p_\mathrm{T}$. No rapidity dependence is observed. The ratio of the B$^0$ to B$^+$ hadron production fractions, $f_\mathrm{d} / f_\mathrm{u}$, measured using the B$^0$$\to$ J$/\psi$ K$^{*0}$ decay channel, is found to be consistent with unity and independent of $p_\mathrm{T}$ and rapidity, as expected from isospin invariance.
The $\mathrm{J/\psi \phi}$, $\mathrm{J/\psi K}$, and $\mathrm{J/\psi} \mathrm{K}^{*0}$ invariant mass distributions, for $\mathrm{B}$ meson candidates with $20 < p_T < 23$ GeV, and asociated fits as described in the text.
The $\mathrm{J/\psi \phi}$, $\mathrm{J/\psi K}$, and $\mathrm{J/\psi} \mathrm{K}^{*0}$ invariant mass distributions, for $\mathrm{B}$ meson candidates with $20 < p_T < 23$ GeV, and asociated fits as described in the text.
The $\mathrm{J/\psi \phi}$, $\mathrm{J/\psi K}$, and $\mathrm{J/\psi} \mathrm{K}^{*0}$ invariant mass distributions, for $\mathrm{B}$ meson candidates with $20 < p_T < 23$ GeV, and asociated fits as described in the text.
Measurements are presented of the B$^0_\mathrm{S}$$\to$$\mu^+\mu^-$ branching fraction and effective lifetime, as well as results of a search for the B$^0$$\to$$\mu^+\mu^-$ decay in proton-proton collisions at $\sqrt{s}$ = 13 TeV at the LHC. The analysis is based on data collected with the CMS detector in 2016-2018 corresponding to an integrated luminosity of 140 fb$^{-1}$. The branching fraction of the B$^0_\mathrm{S}$$\to$$\mu^+\mu^-$ decay and the effective B$^0_\mathrm{S}$ meson lifetime are the most precise single measurements to date. No evidence for the B$^0$$\to$$\mu^+\mu^-$ decay has been found. All results are found to be consistent with the standard model predictions and previous measurements.
The measured branching fraction and effective lifetime for Bs to mu+mu- decay; the branching fraction and upper limits for B0 to mu+mu- decay.
The distribution of the B+ meson pT after the sPlot background subtraction in data and simulation for B+ to J/psi K+ events. The MC distribution is normalized to the data integral.
The distribution of the Bs meson pT after the sPlot background subtraction in data and simulation for Bs to mu+mu- events. The MC distribution is normalized to the data integral.
Using a data sample of $\sqrt{s} =$ 13 TeV proton-proton collisions collected by the CMS experiment at the LHC in 2017 and 2018 with an integrated luminosity of 103 fb$^{-1}$, the B$^0$$\to$$\psi$(2S)K$^0_\mathrm{S}$ and B$^0_\mathrm{S}$$\to$$\psi$(2S)K$^0_\mathrm{S}\pi^+\pi^-$ decays are observed with significances exceeding 5 standard deviations. The resulting branching fraction ratios, measured for the first time, correspond to $\mathcal{B}$(B$^0_\mathrm{S}$$\to$$\psi$(2S)K$^0_\mathrm{S}$) / $\mathcal{B}$(B$^0$$\to$$\psi$(2S)K$^0_\mathrm{S}$) = (3.33 $\pm$ 0.69 (stat) $\pm$ 0.11 (syst) $\pm$ 0.34 ($f_\mathrm{s} / f_\mathrm{d}$)) $\times$ 10$^{-2}$ and $\mathcal{B}$(B$^0$$\to$$\psi$(2S)K$^0_\mathrm{S}\pi^+\pi^-$) / $\mathcal{B}$(B$^0$$\to$$\psi$(2S)K$^0_\mathrm{S}$) = 0.480 $\pm$ 0.013 (stat) $\pm$ 0.032 (syst), where the last uncertainty in the first ratio is related to the uncertainty in the ratio of production cross sections of B$^0_\mathrm{s}$ and B$^0$ mesons, $f_\mathrm{s} / f_\mathrm{d}$.
The measured branching fraction ratios
The measured branching fraction ratios
The measured branching fraction ratios
The ratios of the production cross sections between the excited $\Upsilon$(2S) and $\Upsilon$(3S) mesons and the $\Upsilon$(1S) ground state, detected via their decay into two muons, are studied as a function of the number of charged particles in the event. The data are from proton-proton collisions at $\sqrt{s} =$ 7 TeV, corresponding to an integrated luminosity of 4.8 fb$^{-1}$, collected with the CMS detector at the LHC. Evidence of a decrease in these ratios as a function of the particle multiplicity is observed, more pronounced at low transverse momentum $p_\mathrm{T}^{\mu\mu}$. For $\Upsilon$(nS) mesons with $p_\mathrm{T}^{\mu\mu}$ $\gt$ 7 GeV, where most of the data were collected, the correlation with multiplicity is studied as a function of the underlying event transverse sphericity and the number of particles in a cone around the $\Upsilon$(nS) direction. The ratios are found to be multiplicity independent for jet-like events. The mean $p_\mathrm{T}^{\mu\mu}$ values for the $\Upsilon$(nS) states as a function of particle multiplicity are also measured and found to grow more steeply as their mass increases.
The measured ratios $\Upsilon(2$S$)\,/\,\Upsilon(1$S$)$ and $\Upsilon(3$S$)\,/\,\Upsilon(1$S$)$ with $p_T(\Upsilon(n$S$))>7\,GeV$ and $|y(\Upsilon(n$S$))| < 1.2$, as a function of track multiplicity $N_{track}$
The measured ratios $\Upsilon(2$S$)\,/\,\Upsilon(1$S$)$ and $\Upsilon(3$S$)\,/\,\Upsilon(1$S$)$ with $p_T(\Upsilon(n$S$))>0\,GeV$ and $|y(\Upsilon(n$S$))| < 1.93$, as a function of track multiplicity $N_{track}$.
Mean $p_T$ values of the $\Upsilon(1$S$)$, $\Upsilon(2$S$)$, and $\Upsilon(3S)$ states with $p_T\,>\,7\,GeV$ and $|y|\,<\,1.2$ as a function of track multiplicity $N_{track}$
The $B_\mathrm{c}^+$ meson is observed for the first time in heavy ion collisions. Data from the CMS detector are used to study the production of the $B_\mathrm{c}^+$ meson in lead-lead (PbPb) and proton-proton (pp) collisions at a center-of-mass energy per nucleon pair of $\sqrt{s_{\mathrm{NN}}} =$ 5.02 TeV, via the $B_\mathrm{c}^+ \to (J/\psi\to\mu^+\mu^-)\mu^+\nu_\mu$ decay. The $B_\mathrm{c}^+$ nuclear modification factor, derived from the PbPb-to-pp ratio of production cross sections, is measured in two bins of the trimuon transverse momentum and of the PbPb collision centrality. The B$_\mathrm{c}^+$ meson is shown to be less suppressed than quarkonia and most of the open heavy-flavor mesons, suggesting that effects of the hot and dense nuclear matter created in heavy ion collisions contribute to its production. This measurement sets forth a promising new probe of the interplay of suppression and enhancement mechanisms in the production of heavy-flavor mesons in the quark-gluon plasma.
The $B_c$ meson production (pp-equivalent) cross-section times branching fraction of the $B_c\rightarrow (J/\psi \rightarrow \mu\mu) \mu \nu_{\mu}$ decay in pp and PbPb collisions. The used kinematic variables correspond to those of the trimuon final state. The two $p_T$ bins correspond to different rapidity ranges. The total uncertainty is decomposed in an uncertainty from the fit and one representing all other sources. The markers of the $p_T^{\mu\mu\mu}$ bins are placed according to the Lafferty-Wyatt prescription.
The $B_c$ meson nuclear modification factor in PbPb collisions, in $p_T^{\mu\mu\mu}$ bins corresponding to different trimuon rapidity ranges. The total uncertainty is decomposed in a bin-to-bin-uncorrelated uncertainty and one fully correlated along the two bins. The markers of the $p_T^{\mu\mu\mu}$ bins are placed at the average of the Lafferty-Wyatt prescriptions applied to the pp and PbPb spectra.
The $B_c$ meson nuclear modification factor in PbPb collisions, in centrality bins, integrated over the studied kinematic range. The cut on the trimuon rapidity depends on the trimuon $p_T$. The total uncertainty is decomposed in a bin-to-bin-uncorrelated uncertainty and one fully correlated along the two bins. The centrality bin markers are placed at the minimum bias average number of participants $N_{part}$.
The $\Xi^-_\mathrm{b} \pi^+ \pi^-$ invariant mass spectrum is investigated with an event sample of proton-proton collisions at $\sqrt{s} = $ 13 TeV, collected by the CMS experiment at the LHC in 2016-2018 and corresponding to an integrated luminosity of 140 fb$^{-1}$. The ground state $\Xi^-_\mathrm{b}$ is reconstructed via its decays to J$/\psi \Xi^-$ and J$/\psi \Xi^-\Lambda$K$^-$. A narrow resonance, labeled $\Xi_\mathrm{b}$(6100)$^-$, is observed at a $\Xi^-_\mathrm{b} \pi^+ \pi^-$ invariant mass of 6100.3 $\pm$ 0.2 (stat) $\pm$ 0.1 (syst) $\pm$ 0.6 ($\Xi^-_\mathrm{b}$) MeV, where the last uncertainty reflects the precision of the $\Xi^-_\mathrm{b}$ baryon mass. The upper limit on the $\Xi_\mathrm{b}$(6100)$^-$ natural width is determined to be 1.9 MeV at 95% confidence level. Following analogies with the established excited $\Xi_\mathrm{c}$ baryon states, the new $\Xi_\mathrm{b}$(6100)$^-$ resonance and its decay sequence are consistent with the orbitally excited $\Xi^-_\mathrm{b}$ baryon, with spin and parity quantum numbers $J^P=$ 3/2$^-$.
Measured mass
Measured mass difference
Measured natural width
A study of the $\mathrm{B}^{+} \rightarrow \mathrm{J}/\psi \bar{\Lambda} \mathrm{p}$ decay is reported, using proton-proton collision data collected at $\sqrt{s}= 8~\mathrm{TeV}$ by the CMS experiment at the LHC, corresponding to an integrated luminosity of $19.6~\mathrm{fb}^{-1}$. The ratio of branching fractions $\frac{{\cal B}(\mathrm{B}^{+} \rightarrow \mathrm{J}/\psi \bar{\Lambda} \mathrm{p})}{{\cal B}(\mathrm{B}^{+} \rightarrow \mathrm{J}/\psi \mathrm{K}^{*+})}$ is measured to be $1.054\pm0.057~\text{(stat)} \pm0.028~\text{(syst)}\pm0.011({\cal B})\%$, where the first uncertainty is statistical, the second is systematic, and the third reflects the uncertainties in the world-average branching fractions. The invariant mass distributions of $\mathrm{J}/\psi \bar{\Lambda}$, $\mathrm{J}/\psi \mathrm{p}$, and $\bar{\Lambda} \mathrm{p}$ systems produced in the $\mathrm{B}^{+} \rightarrow \mathrm{J}/\psi \bar{\Lambda} \mathrm{p}$ decay are investigated and found to be inconsistent with the pure phase space hypothesis. The analysis is extended by using a model-independent angular amplitude analysis, which shows that the inclusion of contributions from excited kaons in the $\bar{\Lambda} \mathrm{p}$ system does improve the description of the observed invariant mass distributions.
The measured ratio of branching fractios
Using a data sample of proton-proton collisions at $\sqrt{s} =$ 13 TeV, corresponding to an integrated luminosity of 140 fb$^{-1}$ collected by the CMS experiment in 2016-2018, the B$^0_\mathrm{s}$ $\to$ X(3872)$\phi$ decay is observed. Decays into J/$\psi\,\pi^+\pi^-$ and K$^+$K$^-$ are used to reconstruct, respectively, the X(3872) and $\phi$. The ratio of the product of branching fractions $\mathcal{B}($B$^0_\mathrm{s}$ $\to$ X(3872)$\phi)\,\mathcal{B}($X(3872) $\to$ J$/\psi\,\pi^+\pi^-)$ to the product $\mathcal{B}($B$^0_\mathrm{s}$ $\to$ $\psi$(2S)$\phi)\,\mathcal{B}(\psi$(2S) $\to$ J/$\psi\,\pi^+\pi^-)$ is measured to be (2.21 $\pm$ 0.29 (stat) $\pm$ 0.17 (syst))%. The ratio $\mathcal{B}($B$^0_\mathrm{s}$ $\to$ X(3872)$\phi) / \mathcal{B}($B$^{0}$ $\to$ X(3872)K$^0)$ is found to be consistent with one, while the ratio $\mathcal{B}($B$^0_\mathrm{s}$ $\to$ X(3872)$\phi) / \mathcal{B}($B$^+$ $\to$ X(3872)K$^+)$ is two times smaller. This suggests a difference in the production dynamics of the X(3872) in B$^0$ and B$^0_\mathrm{s}$ meson decays compared to B$^+$. The reported observation may shed new light on the nature of the X(3872) particle.
The measured ratio of branching fraction products
The observation of the $\Lambda_\mathrm{b}^0 \to$J/$\psi \Lambda \phi$ decay is reported using proton-proton collision data collected at $\sqrt{s} =$ 13 TeV by the CMS experiment at the LHC in 2018, corresponding to an integrated luminosity of 60 fb$^{-1}$. The ratio of the branching fractions $\mathcal{B}(\Lambda_\mathrm{b}^0 \to$J/$\psi \Lambda \phi)/\mathcal{B}(\Lambda_\mathrm{b}^0\to\psi \Lambda)$ is measured to be (8.26$\pm$0.90 (stat) $\pm$ 0.68 (syst) $\pm$ 0.11 $(\mathcal{B}))\times $10$^{-2}$, where the first uncertainty is statistical, the second is systematic, and the last uncertainty reflects the uncertainties in the world-average branching fractions of $\phi$ and $\psi$(2S) decays to the reconstructed final states.
The measured ratio of branching fractions
A study of excited $\Lambda_\mathrm{b}^0$ baryons is reported, based on a data sample collected in 2016-2018 with the CMS detector at the LHC in proton-proton collisions at a center-of-mass energy of 13 TeV, corresponding to an integrated luminosity of up to 140 fb$^{-1}$. The existence of four excited $\Lambda_\mathrm{b}^0$ states: $\Lambda_\mathrm{b}$(5912)$^0$, $\Lambda_\mathrm{b}$(5920)$^0$, $\Lambda_\mathrm{b}$(6146)$^0$, and $\Lambda_\mathrm{b}$(6152)$^0$ in the $\Lambda_\mathrm{b}^0\pi^+\pi^-$ mass spectrum is confirmed, and their masses are measured. The $\Lambda_\mathrm{b}^0\pi^+\pi^-$ mass distribution exhibits a broad excess of events in the region of 6040-6100 MeV, whose origin cannot be discerned with the present data.
Measured masses
Measured mass differences
A search for exotic decays of the Higgs boson to a pair of light pseudoscalar particles a$_1$ is performed under the hypothesis that one of the pseudoscalars decays to a pair of opposite sign muons and the other decays to b$\overline{\mathrm{b}}$. Such signatures are predicted in a number of extensions of the standard model (SM), including next-to-minimal supersymmetry and two-Higgs-doublet models with an additional scalar singlet. The results are based on a data set of proton-proton collisions corresponding to an integrated luminosity of 35.9 fb$^{-1}$, accumulated with the CMS experiment at the CERN LHC in 2016 at a centre-of-mass energy of 13 TeV. No statistically significant excess is observed with respect to the SM backgrounds in the search region for pseudoscalar masses from 20 GeV to half of the Higgs boson mass. Upper limits at 95% confidence level are set on the product of the production cross section and branching fraction, $\sigma_{\mathrm{h}}\mathcal{B}$(h $\to$ a$_1$ a$_1$ $\to$ $\mu^+\mu^-\mathrm{b}\bar{\mathrm{b}}$), ranging from 5 to 33 fb, depending on the pseudoscalar mass. Corresponding limits on the branching fraction, assuming the SM prediction for $\sigma_{\mathrm{h}}$, are (1$-$7)$\times$ 10$^{-4}$.
Observed and expected upper limits at 95% CL on the product of the Higgs boson production cross section and B(h->aa->mumubb)
Observed and expected upper limits at 95% CL on the branching fraction of (h->aa->mumubb)
A search is presented for massive narrow resonances decaying either into two Higgs bosons, or into a Higgs boson and a W or Z boson. The decay channels considered are HH$\to \mathrm{b\overline{b}}\tau^{+}\tau^{-}$ and VH$ \to \mathrm{q\overline{q}}\tau^{+}\tau^{-}$, where H denotes the Higgs boson, and V denotes the W or Z boson. This analysis is based on a data sample of proton-proton collisions collected at a center-of-mass energy of 13 TeV by the CMS Collaboration, corresponding to an integrated luminosity of 35.9 fb$^{-1}$. For the TeV-scale mass resonances considered, substructure techniques provide ways to differentiate among the hadronization products from vector boson decays to quarks, Higgs boson decays to bottom quarks, and quark- or gluon-induced jets. Reconstruction techniques are used that have been specifically optimized to select events in which the tau lepton pair is highly boosted. The observed data are consistent with standard model expectations and upper limits are set at 95% confidence level on the product of cross section and branching fraction for resonance masses between 0.9 and 4.0 TeV. Exclusion limits are set in the context of bulk radion and graviton models: spin-0 radion resonances are excluded below a mass of 2.7 TeV at 95% confidence level. In the spin-1 heavy vector triplet framework, mass-degenerate W' and Z' resonances with dominant couplings to the standard model gauge bosons are excluded below a mass of 2.8 TeV at 95% confidence level. There are the first limits for these decay channels at $\sqrt{s}=$ 13 TeV.
Observed 95% CL upper limits on the product of the production cross section and the branching fraction for a new spin-0 resonance decaying to HH, as a function of the resonance mass hypothesis.
Observed 95% CL upper limits on the product of the production cross section and the branching fraction for a new spin-2 resonance decaying to HH, as a function of the resonance mass hypothesis.
Observed 95% CL upper limits on the product of the production cross section and the branching fraction for a new spin-1 W prime resonance decaying to WH, as a function of the resonance mass hypothesis.
Three of the most significant measured deviations from standard model predictions, the enhanced decay rate for B $\to$ D$^{(*)}\tau\nu$, hints of lepton universality violation in B $\to$ K$^{(*)}\ell\ell$ decays, and the anomalous magnetic moment of the muon, can be explained by the existence of leptoquarks (LQs) with large couplings to third-generation quarks and masses at the TeV scale. The existence of these states can be probed at the LHC in high energy proton-proton collisions. A novel search is presented for pair production of LQs coupled to a top quark and a muon using data at a center-of-mass energy of 13 TeV, corresponding to an integrated luminosity of 35.9 fb$^{-1}$, recorded by the CMS experiment. No deviation from the standard model prediction has been observed and scalar LQs decaying exclusively into t$\mu$ are excluded up to masses of 1420 GeV. The results of this search are combined with those from previous searches for LQ decays into t$\tau$ and b$\nu$, which excluded scalar LQs below masses of 900 and 1080 GeV. Vector LQs are excluded up to masses of 1190 GeV for all possible combinations of branching fractions to t$\mu$, t$\tau$ and b$\nu$. With this analysis, all relevant couplings of LQs with an electric charge of -1/3 to third-generation quarks are probed for the first time.
Distributions for $M_{LQ}^{rec}$ (category A) after applying the full selection. All backgrounds are normalized according to the post-fit nuisance parameters based on the corresponding SM cross sections.
Distributions for $S_{T}$ (category B) after applying the full selection and estimating the $t\overline{t}$ and DY+jets background contributions from data in category B. All backgrounds are normalized according to the post-fit nuisance parameters based on the corresponding SM cross sections.
Observed upper limits on the production cross section for pair production of LQs decaying into a top quark and a muon or a $\tau$ lepton at 95% CL in the $M_{LQ} - B(LQ \rightarrow t\mu)$ plane.
Measurements of $\mathrm{B}^*_\mathrm{s2}(5840)^0$ and $\mathrm{B}_\mathrm{s1}(5830)^0$ mesons are performed using a data sample of proton-proton collisions corresponding to an integrated luminosity of 19.6 fb$^{-1}$, collected with the CMS detector at the LHC at a centre-of-mass energy of 8 TeV. The analysis studies $P$-wave $\mathrm{B}^0_\mathrm{S}$ meson decays into $\mathrm{B}^{(*)+}\mathrm{K}^-$ and $\mathrm{B}^{(*)0}\mathrm{K}^0_\mathrm{S}$, where the $\mathrm{B}^+$ and $\mathrm{B}^0$ mesons are identified using the decays $\mathrm{B}^+\to\mathrm{J}/\psi\,\mathrm{K}^+$ and $\mathrm{B}^0\to\mathrm{J}/\psi\,\mathrm{K}^*(892)^0$. The masses of the $P$-wave $\mathrm{B}^0_\mathrm{S}$ meson states are measured and the natural width of the $\mathrm{B}^*_\mathrm{s2}(5840)^0$ state is determined. The first measurement of the mass difference between the charged and neutral $\mathrm{B}^*$ mesons is also presented. The $\mathrm{B}^*_\mathrm{s2}(5840)^0$ decay to $\mathrm{B}^0\mathrm{K}^0_\mathrm{S}$ is observed, together with a measurement of its branching fraction relative to the $\mathrm{B}^*_\mathrm{s2}(5840)^0\to\mathrm{B}^+\mathrm{K}^-$ decay.
The $\mathrm{J}/\psi\mathrm{K}^+$ invariant mass distribution in data
The $\mathrm{J}/\psi\mathrm{K}^{*0}$ invariant mass distribution in data
The $\mathrm{B}^+\pi^-$ invariant mass distribution of the selected candidates in data
A search for an exotic decay of the Higgs boson to a pair of light pseudoscalar bosons is performed for the first time in the final state with two b quarks and two $\tau$ leptons. The search is motivated in the context of models of physics beyond the standard model (SM), such as two Higgs doublet models extended with a complex scalar singlet (2HDM+S), which include the next-to-minimal supersymmetric SM (NMSSM). The results are based on a data set of proton-proton collisions corresponding to an integrated luminosity of 35.9 fb$^{-1}$, accumulated by the CMS experiment at the LHC in 2016 at a center-of-mass energy of 13 TeV. Masses of the pseudoscalar boson between 15 and 60 GeV are probed, and no excess of events above the SM expectation is observed. Upper limits between 3 and 12% are set on the branching fraction $\mathcal{B}$(h $\to$ aa $\to$ 2$\tau$2b) assuming the SM production of the Higgs boson. Upper limits are also set on the branching fraction of the Higgs boson to two light pseudoscalar bosons in different 2HDM+S scenarios. Assuming the SM production cross section for the Higgs boson, the upper limit on this quantity is as low as 20% for a mass of the pseudoscalar of 40 GeV in the NMSSM.
Expected and observed 95% CL upper limits on (sigma(pp->h)/sigma(pp->hSM)) * B(h -> aa -> bbtautau) as a function of m(a), where h(SM) is the Higgs boson of the standard model, h is the observed particle with mass of 125 GeV, and a denotes a light Higgs-like state, as obtained from the 13 TeV data.
A search for Higgs bosons that decay into a bottom quark-antiquark pair and are accompanied by at least one additional bottom quark is performed with the CMS detector. The data analyzed were recorded in proton-proton collisions at a centre-of-mass energy of $\sqrt{s} =$ 13 TeV at the LHC, corresponding to an integrated luminosity of 35.7 fb$^{-1}$. The final state considered in this analysis is particularly sensitive to signatures of a Higgs sector beyond the standard model, as predicted in the generic class of two Higgs doublet models (2HDMs). No signal above the standard model background expectation is observed. Stringent upper limits on the cross section times branching fraction are set for Higgs bosons with masses up to 1300 GeV. The results are interpreted within several MSSM and 2HDM scenarios.
Expected and observed 95% CL upper limits on sigma(pp->b+H(MSSM)+X) * B(H(MSSM) -> bb) in pb as a function of m(H(MSSM)), where H(MSSM) denotes a heavy Higgs-like state like the H and A bosons of MSSM and 2HDM, as obtained from the 13 TeV data.
Expected and observed 95% CL upper limits on tan(beta) as a function of m(A) in the mhmodp benchmark scenario for a higgsino mass parameter of mu=+200 GeV. Since theoretical predictions are not reliable for tan(beta)>60, entries for which tan(beta) would exceed this value are indicated by N/A.
Expected and observed 95% CL upper limits on tan(beta) as a function of m(A) in the hMSSM benchmark scenario. Since theoretical predictions are not reliable for tan(beta)>60, entries for which tan(beta) would exceed this value are indicated by N/A.
A search is presented for the production of two Higgs bosons in final states containing two photons and two bottom quarks. Both resonant and nonresonant hypotheses are investigated. The analyzed data correspond to an integrated luminosity of 19.7 inverse femtobarns of proton-proton collisions at sqrt(s) = 8 TeV collected with the CMS detector. Good agreement is observed between data and predictions of the standard model (SM). Upper limits are set at 95% confidence level on the production cross section of new particles and compared to the prediction for the existence of a warped extra dimension. When the decay to two Higgs bosons is kinematically allowed, assuming a mass scale Lambda[R] = 1 TeV for the model, the data exclude a radion scalar at masses below 980 GeV. The first Kaluza-Klein excitation mode of the graviton in the RS1 Randall-Sundrum model is excluded for masses between 325 and 450 GeV. An upper limit of 0.71 pb is set on the nonresonant two-Higgs-boson cross section in the SM-like hypothesis. Limits are also derived on nonresonant production assuming anomalous Higgs boson couplings.
Observed $m_\mathrm{jj}$ spectrum (black points) compared with a background estimate (black line), obtained in background only hypothesis, for HPHP category. The simulated radion resonances of $m_\mathrm{X} = 1.5$ and 2 TeV are also shown. Observed and expected 95% CL upper limits on the product of cross section and the branching fraction sigma(pp->X)*B(X->HH) obtained through a combination of the two event categories. The limits for mX = 400 GeV are shown for both Low mass and High mass signal extraction methods.
Observed and expected 95% CL upper limits on the product of cross section and the branching fraction sigma(pp->X)*B(X->HH->gamma gamma b b ) for the nonresonant BSM analysis, performed by changing the parameters $kappa_$lambda, y_t and c_2 while keeping all other parameters fixed at the SM predictions.
Signal efficiencies in the four different signal regions for the nonresonant BSM analysis, performed by changing the parameters $kappa_$lambda, y_t and c_2 while keeping all other parameters fixed at the SM predictions. The four signal regions are made in b-tag and m_HH categries, being those: "Low-purity, High-mass" (LPHM), "Low-purity, Low-mass" (LPLM), "High-purity, High-mass" (HPHM) and "High-purity, Low-mass" (HPLM).
A search for neutral Higgs bosons decaying into a b-bbar quark pair and produced in association with at least one additional b quark is presented. This signature is sensitive to the Higgs sector of the minimal supersymmetric standard model (MSSM) with large values of the parameter tan(beta). The analysis is based on data from proton-proton collisions at a center-of-mass energy of 8 TeV collected with the CMS detector at the LHC, corresponding to an integrated luminosity of 19.7 inverse femtobarns. The results are combined with a previous analysis based on 7 TeV data. No signal is observed. Stringent upper limits on the cross section times branching fraction are derived for Higgs bosons with masses up to 900 GeV, and the results are interpreted within different MSSM benchmark scenarios, m[h,max], m[h,mod+], m[h,mod-], light-stau and light-stop. Observed 95% confidence level upper limits on tan(beta), ranging from 14 to 50, are obtained in the m[h,mod+] benchmark scenario.
Expected and observed 95% CL upper limits on sigma(pp->b+ H(MSSM)+X) * B(H(MSSM) -> bb) in pb as a function of m(H(MSSM)), where H(MSSM) denotes a generic Higgs-like state, as obtained from the 8 TeV data.
Expected and observed 95% CL upper limits on tan(beta) as a function of mA in the mh-max benchmark scenario for mu=+200 GeV, obtained from a combination of the 7 and 8 TeV data.
Expected and observed 95% CL upper limits on tan(beta) as a function of mA in the mh-mod+ benchmark scenario for mu=+200 GeV, obtained from a combination of the 7 and 8 TeV data.
A search for a standard model Higgs boson produced in association with a top-quark pair and decaying to bottom quarks is presented. Events with hadronic jets and one or two oppositely charged leptons are selected from a data sample corresponding to an integrated luminosity of 19.5 inverse femtobarns collected by the CMS experiment at the LHC in pp collisions at a centre-of-mass energy of 8 TeV. In order to separate the signal from the larger t t-bar + jets background, this analysis uses a matrix element method that assigns a probability density value to each reconstructed event under signal or background hypotheses. The ratio between the two values is used in a maximum likelihood fit to extract the signal yield. The results are presented in terms of the measured signal strength modifier, mu, relative to the standard model prediction for a Higgs boson mass of 125 GeV. The observed (expected) exclusion limit at a 95% confidence level is mu < 4.2 (3.3), corresponding to a best fit value mu-hat = 1.2 +1.6 -1.5.
The best-fit values of the signal strength modifier obtained from the single lepton (SL) and dilepton (DL) channels alone,and from their combination (COMBINED). The observed 95% CL upper limit (UL) on mu are given in the third column, and are compared to the median expected limits for both the signal-plus-background and for the background-only hypotheses. For the latter, the 1sigma and 2sigma CL intervals are also given.
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