A search for a Higgs boson decaying into a pair of electrons or muons and a photon is described. Higgs boson decays to a Z boson and a photon (H $\to$ Z$\gamma\to\ell\ell\gamma$, $\ell =$ e or $\mu$), or to two photons, one of which has an internal conversion into a muon pair (H $\to\gamma^{*}\gamma\to\mu\mu\gamma$) were considered. The analysis is performed using a data set recorded by the CMS experiment at the LHC from proton-proton collisions at a center-of-mass energy of 13 TeV, corresponding to an integrated luminosity of 35.9 fb$^{-1}$. No significant excess above the background prediction has been found. Limits are set on the cross section for a standard model Higgs boson decaying to opposite-sign electron or muon pairs and a photon. The observed limits on cross section times the corresponding branching fractions vary between 1.4 and 4.0 (6.1 and 11.4) times the standard model cross section for H $\to\gamma^{*}\gamma\to\mu\mu\gamma$ (H $\to$ Z$\gamma\to\ell\ell\gamma$) in the 120-130 GeV mass range of the $\ell\ell\gamma$ system. The H $\to\gamma^*\gamma\to\mu\mu\gamma$ and H $\to$ Z$\gamma\to\ell\ell\gamma$ analyses are combined for $m_\mathrm{H} =$ 125 GeV, obtaining an observed (expected) 95% confidence level upper limit of 3.9 (2.0) times the standard model cross section.
Exclusion limit, at 95% CL, on the cross section of the $H \rightarrow \gamma^{*}\gamma \rightarrow \mu\mu\gamma$ process relative to the SM prediction, as a function of the Higgs boson mass.
Exclusion limit, at 95% CL, on the cross section of the $H \rightarrow Z\gamma \rightarrow ll\gamma$ process relative to the SM prediction, as a function of the Higgs boson mass.
Exclusion limit, at 95% CL, on the cross section of the $H \rightarrow ll\gamma$ relative to the SM prediction, for an SM Higgs boson of $m_{H} = 125$ GeV. The upper limits of each analysis category, as well as their combinations, are shown.
Measurements of prompt $\psi$(2S) meson production cross sections in proton-lead (pPb) and proton-proton (pp) collisions at a nucleon-nucleon center-of-mass energy of $\sqrt{s_{_\mathrm{NN}}}=$ 5.02 TeV are reported. The results are based on pPb and pp data collected by the CMS experiment at the LHC, corresponding to integrated luminosities of 34.6 nb$^{-1}$ and 28.0 pb$^{-1}$, respectively. The nuclear modification factor $R_\mathrm{pPb}$ is measured for prompt $\psi$(2S) in the transverse momentum range 4 $<$ p$_\mathrm{T}$ $<$ 30 GeV$/c$ and the center-of-mass rapidity range $-$2.4 $< y_\mathrm{cm} <$ 1.93. The results on $\psi$(2S) $R_\mathrm{pPb}$ are compared to the corresponding modification factor for prompt J$/\psi$ mesons and are found to be more suppressed than the J$/\psi$ states over the entire kinematic range studied.
Differential cross section (multiplied by the dimuon branching fraction) of prompt $\psi$(2S) mesons in pPb collisions at $\sqrt(s_{\textrm{NN}})=5.02 $ TeV, as a function of $p_{\textrm{T}}$, for four backward $y_{\mathrm{CM}}$ regions. The fully correlated luminosity uncertainty of 3.5% is not included in the point-by-point uncertainty. NOTE- The cross section unit is nb (nano barn); the y-axes of the figures in the publication show pb (pico barn) by mistake.
Differential cross section (multiplied by the dimuon branching fraction) of prompt $\psi$(2S) mesons in pPb collisions at $\sqrt(s_{\textrm{NN}})=5.02 $ TeV, as a function of $p_{\textrm{T}}$, for three forward $y_{\mathrm{CM}}$ regions. The fully correlated luminosity uncertainty of 3.5% is not included in the point-by-point uncertainty. NOTE- The cross section unit is nb (nano barn); the y-axes of the figures in the publication show pb (pico barn) by mistake.
Differential cross section (multiplied by the dimuon branching fraction) of prompt $\psi$(2S) mesons in pp collisions at $\sqrt(s)=5.02 $ TeV, as a function of $p_{\textrm{T}}$, for four $y_{\mathrm{CM}}$ regions. The fully correlated luminosity uncertainty of 2.3% is not included in the point-by-point uncertainty. NOTE- The cross section unit is nb (nano barn); the y-axes of the figures in the publication show pb (pico barn) by mistake.
Measurements are presented of the lifetimes of the B$^0$, B$^0_\mathrm{s}$, $\Lambda^0_\mathrm{b}$, and B$_\mathrm{c}^+$ hadrons using the decay channels B$^0\to$ J/$\psi$K*(892)$^0$, B$^0\to$J/$\psi$K$^0_\mathrm{S}$, B$^0_\mathrm{s}\to$J/$\psi \pi^+\pi^-$, B$^0_\mathrm{s}\to$J/$\psi\phi$(1020), $\Lambda^0_\mathrm{b}\to$J/$\psi\Lambda^0$, and B$_\mathrm{c}\to$J/$\psi\pi^+$. The data sample, corresponding to an integrated luminosity of 19.7 fb$^{-1}$, was collected by the CMS detector at the LHC in proton-proton collisions at $\sqrt{s}=$ 8 TeV. The B$^0$ lifetime is measured to be 453.0 $\pm$ 1.6 (stat) $\pm$ 1.8 (syst) $\mu$m in J/$\psi$K*(892)$^0$ and 457.8 $\pm$ 2.7 (stat) $\pm$ 2.8 (syst) $\mu$m in J/$\psi$K$^0_\mathrm{S}$, which results in a combined measurement of $c\tau_{\mathrm{B}^0} =$ 454.1 $\pm$ 1.4 (stat) $\pm$ 1.7 (syst) $\mu$m. The effective lifetime of the B$^0_\mathrm{s}$ meson is measured in two decay modes, with contributions from different amounts of the heavy and light eigenstates. This results in two different measured lifetimes: $c\tau_{\mathrm{B}^0_\mathrm{s} \to \mathrm{J}/\psi \pi^+\pi^-} =$ 502.7 $\pm$ 10.2 (stat) $\pm$ 3.4 (syst) $\mu$m and $c\tau_{\mathrm{B}^0_\mathrm{s} \to \mathrm{J}/\psi\phi(1020)} =$ 443.9 $\pm$ 2.0 (stat) $\pm$ 1.5 (syst) $\mu$m. The $\Lambda^0_\mathrm{b}$ lifetime is found to be 443.9 $\pm$ 8.2 (stat) $\pm$ 2.8 (syst) $\mu$m. The precision from each of these channels is as good as or better than previous measurements. The B$_\mathrm{c}^+$ lifetime, measured with respect to the B$^+$ to reduce the systematic uncertainty, is 162.3 $\pm$ 7.8 (stat) $\pm$ 4.2 (syst) $\pm$ 0.1 $(\tau_{\mathrm{B}^+})$ $\mu$m. All results are in agreement with current world-average values.
Measurement of b hadron lifetimes in pp collisions at $\sqrt{s}=8$TeV.
Measurement of b hadron lifetimes ratios in pp collisions at $\sqrt{s}=8$TeV.
Estimate $\Gamma_\mathrm{d}$ and $\Delta \Gamma_\mathrm{d}$ in pp collisions at $\sqrt{s}=8$TeV.
This paper reports the measurement of J/psi meson production in proton-proton (pp) and proton-lead (pPb) collisions at a center-of-mass energy per nucleon pair of 5.02 TeV by the CMS experiment at the LHC. The data samples used in the analysis correspond to integrated luminosities of 28 inverse picobarns and 35 inverse nanobarns for pp and pPb collisions, respectively. Prompt and nonprompt J/psi mesons, the latter produced from the decay of B mesons, are measured in their dimuon decay channels. Differential cross sections are measured in the transverse momentum range of 2 < pt < 30 GeV/c, and center-of-mass rapidity ranges of abs(y[CM]) < 2.4 (pp) and -2.87 < y[CM] < 1.93 (pPb). The nuclear modification factor, R[pPb], is measured as functions of both pt and y[CM]. Small modifications of the J/psi cross sections are observed in pPb relative to pp collisions. The ratio of J/psi production cross sections in p-going and Pb-going directions, R[FB], studied as functions of pt and y[CM], shows a significant decrease for increasing transverse energy deposited at large pseudorapidities. These results, which cover a wide kinematic range, provide new insight on the role of cold nuclear matter effects on prompt and nonprompt J/psi production.
Differential cross section (multiplied by the dimuon branching fraction) of prompt J/$\psi$ mesons in pp collisions at forward $y_{\mathrm{CM}}$.
Differential cross section (multiplied by the dimuon branching fraction) of prompt J/$\psi$ mesons in pp collisions at backward $y_{\mathrm{CM}}$.
Differential cross section (multiplied by the dimuon branching fraction) of prompt J/$\psi$ mesons in pPb collisions at forward $y_{\mathrm{CM}}$.
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