A search for exclusive or quasi-exclusive gamma gamma to W+W- production, via pp to p(*) W+W- p(*) to p(*) mu+/- e-/+ at sqrt(s) = 8 TeV, is reported using data corresponding to an integrated luminosity of 19.7 inverse femtobarns. Events are selected by requiring the presence of an electron-muon pair with large transverse momentum pt(mu+/- e-/+) > 30 GeV, and no associated charged particles detected from the same vertex. The 8 TeV results are combined with the previous 7 TeV results (obtained for 5.05 inverse femtobarns of data). In the signal region, 13 (2) events are observed over an expected background of 3.9 +/- 0.6 (0.84 +/-0.15) events for 8 (7) TeV, resulting in a combined excess of 3.4 standard deviations over the background-only hypothesis. The observed yields and kinematic distributions are compatible with the standard model prediction for exclusive and quasi-exclusive gamma gamma to W+W- production. Upper limits on the anomalous quartic gauge coupling operators a[W;0,C] (dimension-6) and f[M0,1,2,3] (dimension-8), the most stringent to date, are derived from the measured dilepton transverse momentum spectrum.
8 TeV cross section multiplied by branching fraction to opposite-sign mue final states, corrected for all experimental efficiencies and extrapolated to the full phase space.
A measurement of the Z gamma to nu nu-bar gamma production cross section in pp collisions at sqrt(s) = 8 TeV is presented, using data corresponding to an integrated luminosity of 19.6 inverse femtobarns collected with the CMS detector at the LHC. This measurement is based on the observation of events with large missing energy and with a single photon with transverse momentum above 145 GeV and absolute pseudorapidity in the range |eta| < 1.44. The measured Z gamma to nu nu-bar gamma production cross section, 52.7 +/- 2.1(stat) +/- 6.4 (syst) +/- 1.4 (lumi) fb, agrees well with the standard model prediction of 50.0 +2.4 -2.2 fb. A study of the photon transverse momentum spectrum yields the most stringent limits to date on the anomalous Z-Z-gamma and Z-gamma-gamma trilinear gauge boson couplings.
Z gamma -> nu nu gamma production cross section.
One-dimensional 95% CL limits on ZVgamma anomalous trilinear gauge couplings from the Z gamma -> nu nu gamma channel.
Associated production of bottomonia and open charm hadrons in $pp$ collisions at $\sqrt{s}=7$ and $8$TeV is observed using data corresponding to an integrated luminosity of 3$fb^{-1}$ accumulated with the LHCb detector. The observation of five combinations, $\Upsilon(1S)D^0$, $\Upsilon(2S)D^0$, $\Upsilon(1S)D^+$, $\Upsilon(2S)D^+$ and $\Upsilon(1S)D^+_{s}$, is reported. Production cross-sections are measured for $\Upsilon(1S)D^0$ and $\Upsilon(1S)D^+$ pairs in the forward region. The measured cross-sections and the differential distributions indicate the dominance of double parton scattering as the main production mechanism. This allows a precise measurement of the effective cross-section for double parton scattering.
Normalized differential cross-section $\frac{1}{\sigma}\frac{ \mathrm{d}\sigma(\Upsilon(1S)D^0)}{\mathrm{d} p_T(\Upsilon(1S))}$ for $2<y(\Upsilon(1S))<4.5$, $2<y(D^0)<4.5$, $p_T(D^0)>1$ GeV/$c$. Only statistical uncertainties are quoted as systematic uncertainties are found to be negligible. The distribution is normalized to unity.
Normalized differential cross-section $\frac{1}{\sigma}\frac{ \mathrm{d}\sigma(\Upsilon(1S)D^+)}{\mathrm{d} p_T(\Upsilon(1S))}$ for $2<y(\Upsilon(1S))<4.5$, $2<y(D^+)<4.5$, $p_T(D^+)>1$ GeV/$c$. Only statistical uncertainties are quoted as systematic uncertainties are found to be negligible. The distribution is normalized to unity.
Normalized differential cross-section $\frac{1}{\sigma}\frac{ \mathrm{d}\sigma(\Upsilon(1S)D^0)}{\mathrm{d} p_T(D^0)}$ for $2<y(\Upsilon(1S))<4.5$, $2<y(D^0)<4.5$, $p_T(D^0)>1$ GeV/$c$. Only statistical uncertainties are quoted as systematic uncertainties are found to be negligible. The distribution is normalized to unity.
A search for pair production of third-generation scalar leptoquarks and supersymmetric top quark partners, top squarks, in final states involving tau leptons and bottom quarks is presented. The search uses events from a data sample of proton-proton collisions corresponding to an integrated luminosity of 19.7 inverse femtobarns, collected with the CMS detector at the LHC with sqrt(s) = 8 TeV. The number of observed events is found to be in agreement with the expected standard model background. Third-generation scalar leptoquarks with masses below 740 GeV are excluded at 95% confidence level, assuming a 100% branching fraction for the leptoquark decay to a tau lepton and a bottom quark. In addition, this mass limit applies directly to top squarks decaying via an R-parity violating coupling lambda'[333]. The search also considers a similar signature from top squarks undergoing a chargino-mediated decay involving the R-parity violating coupling lambda'[3jk]. Each top squark decays to a tau lepton, a bottom quark, and two light quarks. Top squarks in this model with masses below 580 GeV are excluded at 95% confidence level. The constraint on the leptoquark mass is the most stringent to date, and this is the first search for top squarks decaying via lambda'[3jk].
The estimated backgrounds, observed event yields, and expected number of signal events for the leptoquark search. For the simulation-based entries, the statistical and systematic uncertainties are shown separately, in that order.
The estimated backgrounds, observed event yields, and expected number of signal events for the top squark search. For the simulation-based entries, the statistical and systematic uncertainties are shown separately, in that order.
Selection efficiencies in % for the signal in the leptoquark search, estimated from the simulation.
A study is presented of central exclusive production of $\Upsilon(nS)$ states, where the $\Upsilon(nS)$ resonances decay to the $\mu^+\mu^-$ final state, using $pp$ collision data recorded by the LHCb experiment. The cross-section is measured in the rapidity range $2<y(\Upsilon)<4.5$ where the muons are reconstructed in the pseudorapidity range $2<\eta(\mu^\pm)<4.5$. The data sample corresponds to an integrated luminosity of 2.9 fb$^{-1}$ and was collected at centre-of-mass energies of $7$ TeV and $8$ TeV. The measured $\Upsilon(1S)$ and $\Upsilon(2S)$ production cross-sections are \begin{eqnarray} \sigma(pp \to p\Upsilon(1S)p) &=& 9.0 \pm 2.1 \pm 1.7\textrm{ pb and}\nonumber\\ \sigma(pp \to p\Upsilon(2S)p) &=& 1.3 \pm 0.8 \pm 0.3\textrm{ pb},\nonumber \end{eqnarray} where the first uncertainties are statistical and the second are systematic. The $\Upsilon(1S)$ cross-section is also measured as a function of rapidity and is found to be in good agreement with Standard Model predictions. An upper limit is set at 3.4 pb at the 95\% confidence level for the exclusive $\Upsilon(3S)$ production cross-section, including possible contamination from $\chi_b(3P)\to\Upsilon(3S)\gamma$ decays.
Production cross-section for the $\Upsilon(1S)$ resonance in ranges of $\Upsilon(1S)$ rapidity, where the muons are required to lie in the pseudorapidity range $2 < \eta(\mu^{\pm}) < 4.5$. The first uncertainties are statistical and the second ones are systematic.
Differential production cross-section for $\Upsilon(1S)$, where the data have been corrected for the effect of the LHCb geometrical acceptance. The statistical and systematic uncertainties are combined in quadrature.
A comparison of the differential cross sections for the processes Z/gamma* + jets and photon (gamma) + jets is presented. The measurements are based on data collected with the CMS detector at sqrt(s) = 8 TeV corresponding to an integrated luminosity of 19.7 inverse femtobarns. The differential cross sections and their ratios are presented as functions of pt. The measurements are also shown as functions of the jet multiplicity. Differential cross sections are obtained as functions of the ratio of the Z/gamma* pt to the sum of all jet transverse momenta and of the ratio of the Z/gamma* pt to the leading jet transverse momentum. The data are corrected for detector effects and are compared to simulations based on several QCD calculations.
The Z boson differential transverse momentum cross-section in an inclusive $Z/\gamma^{*}+\mathrm{jets}$, $N_{\mathrm{jets}} \geq1$ selection.
The $\gamma$ differential transverse momentum cross-section in an inclusive $\gamma+\mathrm{jets}$, $N_{\mathrm{jets}} \geq1$ selection for central rapidities $\vert y_{\gamma} \vert > 1.4$.
The Z boson differential transverse momentum cross-section in an inclusive $Z/\gamma^{*}+\mathrm{jets}$, $N_{\mathrm{jets}} \geq2$ selection.
A search for a heavy Higgs boson in the H to WW and H to ZZ decay channels is reported. The search is based upon proton-proton collision data samples corresponding to an integrated luminosity of up to 5.1 inverse femtobarns at sqrt(s) = 7 TeV and up to 19.7 inverse femtobarns at sqrt(s) = 8 TeV, recorded by the CMS experiment at the CERN LHC. Several final states of the H to WW and H to ZZ decays are analyzed. The combined upper limit at the 95% confidence level on the product of the cross section and branching fraction exclude a Higgs boson with standard model-like couplings and decays in the range 145 < m[H] < 1000 GeV. We also interpret the results in the context of an electroweak singlet extension of the standard model.
Upper limits at 95\% CL on the cross section for a heavy Higgs boson decaying to a pair of W bosons as a function of its mass and its width relative to a SM-like Higgs boson.
Upper limits at 95\% CL on the cross section for a heavy Higgs boson decaying to a pair of Z bosons as a function of its mass and its width relative to a SM-like Higgs boson.
Upper limits at 95% CL on the cross section for a heavy Higgs boson as a function of its mass and its width relative to a SM-like Higgs boson. Both, gluon-gluon fusion and VBF production processes are combined, assuming a SM-like ratio between the two.
The angular distributions and the differential branching fraction of the decay B0 to K*0(892) mu mu are studied using data corresponding to an integrated luminosity of 20.5 inverse femtobarns collected with the CMS detector at the LHC in pp collisions at sqrt(s) = 8 TeV. From 1430 signal decays, the forward-backward asymmetry of the muons, the K*0(892) longitudinal polarization fraction, and the differential branching fraction are determined as a function of the dimuon invariant mass squared. The measurements are among the most precise to date and are in good agreement with standard model predictions.
The measured values of signal yield, FL, AFB, and differential branching fraction in bins of the dimuon invariant mass squared. The (FL,AFB) correlation factors are also shown.
The measured values of FL, AFB, and differential branching fraction in bins of the dimuon invariant mass squared, combining the 7 TeV and 8 TeV results.
A search for neutral Higgs bosons predicted in the minimal supersymmetric standard model (MSSM) for mu+ mu- decay channels is presented. The analysis uses data collected by the CMS experiment at the LHC in proton-proton collisions at centre-of-mass energies of 7 and 8 TeV, corresponding to integrated luminosities of 5.1 and 19.3 inverse femtobarns, respectively. The search is sensitive to Higgs bosons produced through the gluon fusion process or in association with a bb quark pair. No statistically significant excess is observed in the mu+ mu- mass spectrum. Results are interpreted in the framework of several benchmark scenarios, and the data are used to set an upper limit on the MSSM parameter tan(beta) as a function of the mass of the pseudoscalar A boson in the range from 115 to 300 GeV. Model independent upper limits are given for the product of the cross section and branching fraction for gluon fusion and b quark associated production. They are the most stringent limits obtained to date in this channel.
The 95% CL upper limit on tan B as a function of mA, after combining the data from the two event categories at the two centre-of-mass energies (7 and 8 TeV). The results are obtained in the framework of the mh-mod+ benchmark scenario.
The 95% CL limit on the product of the cross section and the decay branching fraction to two muons as a function of mPHI, obtained from a model independent analysis of the data. The results refer to b quark associated production, obtained using data collected at swrt(s) = 8 TeV.
The 95% CL limit on the product of the cross section and the decay branching fraction to two muons as a function of mPHI, obtained from a model independent analysis of the data. The results refer to gluon-fusion production, obtained using data collected at swrt(s) = 8 TeV.
A search is reported for massive resonances decaying into a quark and a vector boson (W or Z), or two vector bosons (WW, WZ, or ZZ). The analysis is performed on an inclusive sample of multijet events corresponding to an integrated luminosity of 19.7 inverse femtobarns, collected in proton-proton collisions at a centre-of-mass energy of 8 TeV with the CMS detector at the LHC. The search uses novel jet-substructure identification techniques that provide sensitivity to the presence of highly boosted vector bosons decaying into a pair of quarks. Exclusion limits are set at a confidence level of 95% on the production of: (i) excited quark resonances q* decaying to qW and qZ for masses less than 3.2 TeV and 2.9 TeV, respectively, (ii) a Randall-Sundrum graviton G[RS] decaying into WW for masses below 1.2 TeV, and (iii) a heavy partner of the W boson W' decaying into WZ for masses less than 1.7 TeV. For the first time mass limits are set on W' to WZ and G[RS] to WW in the all-jets final state. The mass limits on q* to qW, q* to qZ, W' to WZ, G[RS] to WW are the most stringent to date. A model with a "bulk" graviton G[Bulk] that decays into WW or ZZ bosons is also studied.
DATA - Double W/Z tagged events in HIGH purity bin.
BACKGROUND - Double W/Z tagged background in HIGH purity bin estimated from a fit to data.
BACKGROUND PLUS - Double W/Z tagged background variation upward (1 sigma) in HIGH purity bin estimated from a fit to data.
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