A measurement of the tt production cross section in proton-proton collisions at a centre-of-mass ... more A measurement of the tt production cross section in proton-proton collisions at a centre-of-mass energy of 7 TeV has been performed at the LHC with the CMS detector. The analysis uses a data sample corresponding to an integrated luminosity of 36 pb −1 and is based on the reconstruction of the final state with one isolated, high transverse-momentum electron or muon and three or more hadronic jets. The kinematic properties of the events are used to separate the tt signal from W+jets and QCD multijet background events. The measured cross section is 173 +39 −32 (stat. + syst.) pb, consistent with standard model expectations.
Bioinformatics/computer Applications in The Biosciences, 2010
Rapid expansion of available data about G Protein Coupled Receptor (GPCR) dimers/oligomers over t... more Rapid expansion of available data about G Protein Coupled Receptor (GPCR) dimers/oligomers over the past few years requires an effective system to organize this information electronically. Based on an ontology derived from a community dialog involving colleagues using experimental and computational methodologies, we developed the GPCR-Oligomerization Knowledge Base (GPCR-OKB). GPCR-OKB is a system that supports browsing and searching for GPCR oligomer data. Such data were manually derived from the literature. While focused on GPCR oligomers, GPCR-OKB is seamlessly connected to GPCRDB, facilitating the correlation of information about GPCR protomers and oligomers. Availability and Implementation: The GPCR-OKB web application is freely available at
L'architecture, les mécanismes de la statique et de la dynamique du pelvis rendent difficiles les... more L'architecture, les mécanismes de la statique et de la dynamique du pelvis rendent difficiles les indications thérapeutiques en cas d'incontinence urinaire et/ou de prolapsus, soulignant l'intérêt de bilans précis statiques et dynamiques, en particulier chez les patientes multi-opérées où les modifications anatomiques sont nombreuses. A côté de ses performances purement morphologiques, l'IRM, en utilisant des séquences rapides, est sûrement un examen d'avenir dans l'expertise des déséquilibres de la statique pelvienne. Si la réalisation de l'exploration en décubitus dorsal est un inconvénient de départ à ce jour incontournable, l'absence d'opacification pelvienne instrumentale rend l'IRM beaucoup plus physiologique que le colpocystogramme. Après avoir établi des critères de normalité, nous avons tenté chez des patientes affectées d'une incontinence et/ou d'un prolapsus de mettre en évidence des critères prédictifs pour une décision thérapeutique. Les limites que nous avons rencontrées sont peut être à rapporter à la population (hétérogénéité et importance des antécédents). L'impossibilité de visualiser avec précision le col vésical et la filière ano-rectale, contrairement à l'avis d'auteurs antérieurs, [6] constitute également un handicap. La substitution de l'IRM au colpocystogramme nous apparaît donc aujourd'hui prématurée. Mais la technique, très évolutive, est susceptible d'amendements rapides, notamment par la majoration de la résolution spatiale. Sa place dans les bilans de routine devra sûrement être rediscutée bientôt.
A model-independent search for three-jet hadronic resonance production in pp collisions at a cent... more A model-independent search for three-jet hadronic resonance production in pp collisions at a center-of-mass energy of 7 TeV has been conducted by the CMS Collaboration at the LHC, using a data sample corresponding to an integrated luminosity of 35 pb −1 . Events with high jet multiplicity and a large scalar sum of jet transverse momenta are analyzed. The number of expected standard model background events is found to be in good agreement with the observed events. Limits are set on a model describing the production of R-parity-violating supersymmetric gluino pairs, and gluino masses in the range of 200 to 280 GeV/c 2 are excluded at a 95% confidence level for the first time.
A measurement is presented of the charged hadron multiplicity in hadronic PbPb collisions, as a f... more A measurement is presented of the charged hadron multiplicity in hadronic PbPb collisions, as a function of pseudorapidity and centrality, at a collision energy of 2.76 TeV per nucleon pair. The data sample is collected using the CMS detector and a minimum-bias trigger, with the CMS solenoid off. The number of charged hadrons is measured both by counting the number of reconstructed particle hits and by forming hit doublets of pairs of layers in the pixel detector. The two methods give consistent results. The charged hadron multiplicity density, dN ch /dη| η=0 , for head-on collisions is found to be 1612 ± 55, where the uncertainty is dominated by systematic effects. Comparisons of these results to previous measurements and to various models are also presented.
First measurements of the W -> lnu and Z/gamma* -> ll (l = e, mu) production cross sections in pr... more First measurements of the W -> lnu and Z/gamma* -> ll (l = e, mu) production cross sections in proton-proton collisions at sqrt(s) = 7 TeV are presented using data recorded by the ATLAS experiment at the LHC. The results are based on 2250 W -> lnu and 179 Z/gamma* -> ll candidate events selected from a data set corresponding to an integrated luminosity of approximately 320 nb-1. The measured total W and Z/gamma*-boson production cross sections times the respective leptonic branching ratios for the combined electron and muon channels are $\stotW$ * BR(W -> lnu) = 9.96 +- 0.23(stat) +- 0.50(syst) +- 1.10(lumi) nb and $\stotZg$ * BR(Z/gamma* -> ll) = 0.82 +- 0.06(stat) +- 0.05(syst) +- 0.09(lumi) nb (within the invariant mass window 66 < m_ll < 116 GeV). The W/Z cross-section ratio is measured to be 11.7 +- 0.9(stat) +- 0.4(syst). In addition, measurements of the W+ and W- production cross sections and of the lepton charge asymmetry are reported. Theoretical predictions based on NNLO QCD calculations are found to agree with the measurements.
We solve the following problem proposed by H. Straubing. Given a two letter alphabet A, what is t... more We solve the following problem proposed by H. Straubing. Given a two letter alphabet A, what is the maximal number of states f (n) of the minimal automaton of a subset of A n , the set of all words of length n. We give an explicit formula to compute f (n) and we show that 1 = lim n→∞ nf (n)/2 n ≤ lim n→∞ nf (n)/2 n = 2.
A search for narrow resonances in the dijet mass spectrum is performed using data corresponding t... more A search for narrow resonances in the dijet mass spectrum is performed using data corresponding to an integrated luminosity of 2.9 pb −1 collected by the CMS experiment at the Large Hadron Collider. Upper limits at the 95% confidence level are presented on the product of the resonance cross section, branching fraction into dijets, and acceptance, separately for decays into quark-quark, quark-gluon, or gluon-gluon pairs. The data exclude new particles predicted in the following models at the 95% confidence level: string resonances, with mass less than 2.50 TeV, excited quarks, with mass less than 1.58 TeV, and axigluons, colorons, and E 6 diquarks, in specific mass intervals. This extends previously published limits on these models.
Jet production in PbPb collisions at a nucleon-nucleon center-of-mass energy of 2.76 TeV was stud... more Jet production in PbPb collisions at a nucleon-nucleon center-of-mass energy of 2.76 TeV was studied with the CMS detector at the LHC, using a data sample corresponding to an integrated luminosity of 6.7 µb −1 . Jets are reconstructed using the energy deposited in the CMS calorimeters and studied as a function of collision centrality. With increasing collision centrality, a striking imbalance in dijet transverse momentum is observed, consistent with jet quenching. The observed effect extends from the lower cut-off used in this study (jet p T = 120 GeV/c) up to the statistical limit of the available data sample (jet p T ≈ 210 GeV/c). Correlations of charged particle tracks with jets indicate that the momentum imbalance is accompanied by a softening of the fragmentation pattern of the second most energetic, away-side jet. The dijet momentum balance is recovered when integrating low transverse momentum particles distributed over a wide angular range relative to the direction of the away-side jet.
Search for the standard model Higgs boson decaying to W + W − in the fully leptonic final state i... more Search for the standard model Higgs boson decaying to W + W − in the fully leptonic final state in pp collisions at √ s = 7 TeV
A search for the standard model Higgs boson decaying into two Z bosons with subsequent decay into... more A search for the standard model Higgs boson decaying into two Z bosons with subsequent decay into a final state containing two quark jets and two leptons, H → ZZ ( * ) → qq − + is presented. Results are based on data corresponding to an integrated luminosity of 4.6 fb −1 of proton-proton collisions at √ s = 7 TeV, collected with the CMS detector at the LHC. In order to discriminate between signal and background events, kinematic and topological quantities, including the angular spin correlations of the decay products, are employed. Events are further classified according to the probability of the jets to originate from quarks of light or heavy flavor or from gluons. No evidence for the Higgs boson is found, and upper limits on its production cross section are determined for a Higgs boson of mass between 130 and 600 GeV.
Bose-Einstein correlations have been measured using samples of proton-proton collisions at 0.9 an... more Bose-Einstein correlations have been measured using samples of proton-proton collisions at 0.9 and 2.36 TeV center-of-mass energies, recorded by the CMS experiment at the CERN Large Hadron Collider. The signal is observed in the form of an enhancement of pairs of same-sign charged particles with small relative four-momentum. The size of the correlated particle emission region is seen to increase significantly with the particle multiplicity of the event.
Yields of prompt and non-prompt J/ψ, as well as Υ(1S) mesons, are measured by the CMS experiment ... more Yields of prompt and non-prompt J/ψ, as well as Υ(1S) mesons, are measured by the CMS experiment via their µ + µ − decays in PbPb and pp collisions at √ s NN = 2.76 TeV for quarkonium rapidity |y| < 2.4. Differential cross sections and nuclear modification factors are reported as functions of y and transverse momentum p T , as well as collision centrality. For prompt J/ψ with relatively high p T (6.5 < p T < 30 GeV/c), a strong, centrality-dependent suppression is observed in PbPb collisions, compared to the yield in pp collisions scaled by the number of inelastic nucleon-nucleon collisions.
We present a measurement of the ratio of positive to negative muon fluxes from cosmic ray interac... more We present a measurement of the ratio of positive to negative muon fluxes from cosmic ray interactions in the atmosphere, using data collected by the CMS detector both at ground level and in the underground experimental cavern at the CERN LHC. Muons were detected in the momentum range from 5 GeV/c to 1 TeV/c. The surface flux ratio is measured to be 1.2766 ± 0.0032 (stat.) ± 0.0032 (syst.), independent of the muon momentum, below 100 GeV/c. This is the most precise measurement to date. At higher momenta the data are consistent with an increase of the charge ratio, in agreement with cosmic ray shower models and compatible with previous measurements by deep-underground experiments.
A measurement of the tt production cross section in proton-proton collisions at a centre-of-mass ... more A measurement of the tt production cross section in proton-proton collisions at a centre-of-mass energy of 7 TeV has been performed at the LHC with the CMS detector. The analysis uses a data sample corresponding to an integrated luminosity of 36 pb −1 and is based on the reconstruction of the final state with one isolated, high transverse-momentum electron or muon and three or more hadronic jets. The kinematic properties of the events are used to separate the tt signal from W+jets and QCD multijet background events. The measured cross section is 173 +39 −32 (stat. + syst.) pb, consistent with standard model expectations.
Bioinformatics/computer Applications in The Biosciences, 2010
Rapid expansion of available data about G Protein Coupled Receptor (GPCR) dimers/oligomers over t... more Rapid expansion of available data about G Protein Coupled Receptor (GPCR) dimers/oligomers over the past few years requires an effective system to organize this information electronically. Based on an ontology derived from a community dialog involving colleagues using experimental and computational methodologies, we developed the GPCR-Oligomerization Knowledge Base (GPCR-OKB). GPCR-OKB is a system that supports browsing and searching for GPCR oligomer data. Such data were manually derived from the literature. While focused on GPCR oligomers, GPCR-OKB is seamlessly connected to GPCRDB, facilitating the correlation of information about GPCR protomers and oligomers. Availability and Implementation: The GPCR-OKB web application is freely available at
L'architecture, les mécanismes de la statique et de la dynamique du pelvis rendent difficiles les... more L'architecture, les mécanismes de la statique et de la dynamique du pelvis rendent difficiles les indications thérapeutiques en cas d'incontinence urinaire et/ou de prolapsus, soulignant l'intérêt de bilans précis statiques et dynamiques, en particulier chez les patientes multi-opérées où les modifications anatomiques sont nombreuses. A côté de ses performances purement morphologiques, l'IRM, en utilisant des séquences rapides, est sûrement un examen d'avenir dans l'expertise des déséquilibres de la statique pelvienne. Si la réalisation de l'exploration en décubitus dorsal est un inconvénient de départ à ce jour incontournable, l'absence d'opacification pelvienne instrumentale rend l'IRM beaucoup plus physiologique que le colpocystogramme. Après avoir établi des critères de normalité, nous avons tenté chez des patientes affectées d'une incontinence et/ou d'un prolapsus de mettre en évidence des critères prédictifs pour une décision thérapeutique. Les limites que nous avons rencontrées sont peut être à rapporter à la population (hétérogénéité et importance des antécédents). L'impossibilité de visualiser avec précision le col vésical et la filière ano-rectale, contrairement à l'avis d'auteurs antérieurs, [6] constitute également un handicap. La substitution de l'IRM au colpocystogramme nous apparaît donc aujourd'hui prématurée. Mais la technique, très évolutive, est susceptible d'amendements rapides, notamment par la majoration de la résolution spatiale. Sa place dans les bilans de routine devra sûrement être rediscutée bientôt.
A model-independent search for three-jet hadronic resonance production in pp collisions at a cent... more A model-independent search for three-jet hadronic resonance production in pp collisions at a center-of-mass energy of 7 TeV has been conducted by the CMS Collaboration at the LHC, using a data sample corresponding to an integrated luminosity of 35 pb −1 . Events with high jet multiplicity and a large scalar sum of jet transverse momenta are analyzed. The number of expected standard model background events is found to be in good agreement with the observed events. Limits are set on a model describing the production of R-parity-violating supersymmetric gluino pairs, and gluino masses in the range of 200 to 280 GeV/c 2 are excluded at a 95% confidence level for the first time.
A measurement is presented of the charged hadron multiplicity in hadronic PbPb collisions, as a f... more A measurement is presented of the charged hadron multiplicity in hadronic PbPb collisions, as a function of pseudorapidity and centrality, at a collision energy of 2.76 TeV per nucleon pair. The data sample is collected using the CMS detector and a minimum-bias trigger, with the CMS solenoid off. The number of charged hadrons is measured both by counting the number of reconstructed particle hits and by forming hit doublets of pairs of layers in the pixel detector. The two methods give consistent results. The charged hadron multiplicity density, dN ch /dη| η=0 , for head-on collisions is found to be 1612 ± 55, where the uncertainty is dominated by systematic effects. Comparisons of these results to previous measurements and to various models are also presented.
First measurements of the W -> lnu and Z/gamma* -> ll (l = e, mu) production cross sections in pr... more First measurements of the W -> lnu and Z/gamma* -> ll (l = e, mu) production cross sections in proton-proton collisions at sqrt(s) = 7 TeV are presented using data recorded by the ATLAS experiment at the LHC. The results are based on 2250 W -> lnu and 179 Z/gamma* -> ll candidate events selected from a data set corresponding to an integrated luminosity of approximately 320 nb-1. The measured total W and Z/gamma*-boson production cross sections times the respective leptonic branching ratios for the combined electron and muon channels are $\stotW$ * BR(W -> lnu) = 9.96 +- 0.23(stat) +- 0.50(syst) +- 1.10(lumi) nb and $\stotZg$ * BR(Z/gamma* -> ll) = 0.82 +- 0.06(stat) +- 0.05(syst) +- 0.09(lumi) nb (within the invariant mass window 66 < m_ll < 116 GeV). The W/Z cross-section ratio is measured to be 11.7 +- 0.9(stat) +- 0.4(syst). In addition, measurements of the W+ and W- production cross sections and of the lepton charge asymmetry are reported. Theoretical predictions based on NNLO QCD calculations are found to agree with the measurements.
We solve the following problem proposed by H. Straubing. Given a two letter alphabet A, what is t... more We solve the following problem proposed by H. Straubing. Given a two letter alphabet A, what is the maximal number of states f (n) of the minimal automaton of a subset of A n , the set of all words of length n. We give an explicit formula to compute f (n) and we show that 1 = lim n→∞ nf (n)/2 n ≤ lim n→∞ nf (n)/2 n = 2.
A search for narrow resonances in the dijet mass spectrum is performed using data corresponding t... more A search for narrow resonances in the dijet mass spectrum is performed using data corresponding to an integrated luminosity of 2.9 pb −1 collected by the CMS experiment at the Large Hadron Collider. Upper limits at the 95% confidence level are presented on the product of the resonance cross section, branching fraction into dijets, and acceptance, separately for decays into quark-quark, quark-gluon, or gluon-gluon pairs. The data exclude new particles predicted in the following models at the 95% confidence level: string resonances, with mass less than 2.50 TeV, excited quarks, with mass less than 1.58 TeV, and axigluons, colorons, and E 6 diquarks, in specific mass intervals. This extends previously published limits on these models.
Jet production in PbPb collisions at a nucleon-nucleon center-of-mass energy of 2.76 TeV was stud... more Jet production in PbPb collisions at a nucleon-nucleon center-of-mass energy of 2.76 TeV was studied with the CMS detector at the LHC, using a data sample corresponding to an integrated luminosity of 6.7 µb −1 . Jets are reconstructed using the energy deposited in the CMS calorimeters and studied as a function of collision centrality. With increasing collision centrality, a striking imbalance in dijet transverse momentum is observed, consistent with jet quenching. The observed effect extends from the lower cut-off used in this study (jet p T = 120 GeV/c) up to the statistical limit of the available data sample (jet p T ≈ 210 GeV/c). Correlations of charged particle tracks with jets indicate that the momentum imbalance is accompanied by a softening of the fragmentation pattern of the second most energetic, away-side jet. The dijet momentum balance is recovered when integrating low transverse momentum particles distributed over a wide angular range relative to the direction of the away-side jet.
Search for the standard model Higgs boson decaying to W + W − in the fully leptonic final state i... more Search for the standard model Higgs boson decaying to W + W − in the fully leptonic final state in pp collisions at √ s = 7 TeV
A search for the standard model Higgs boson decaying into two Z bosons with subsequent decay into... more A search for the standard model Higgs boson decaying into two Z bosons with subsequent decay into a final state containing two quark jets and two leptons, H → ZZ ( * ) → qq − + is presented. Results are based on data corresponding to an integrated luminosity of 4.6 fb −1 of proton-proton collisions at √ s = 7 TeV, collected with the CMS detector at the LHC. In order to discriminate between signal and background events, kinematic and topological quantities, including the angular spin correlations of the decay products, are employed. Events are further classified according to the probability of the jets to originate from quarks of light or heavy flavor or from gluons. No evidence for the Higgs boson is found, and upper limits on its production cross section are determined for a Higgs boson of mass between 130 and 600 GeV.
Bose-Einstein correlations have been measured using samples of proton-proton collisions at 0.9 an... more Bose-Einstein correlations have been measured using samples of proton-proton collisions at 0.9 and 2.36 TeV center-of-mass energies, recorded by the CMS experiment at the CERN Large Hadron Collider. The signal is observed in the form of an enhancement of pairs of same-sign charged particles with small relative four-momentum. The size of the correlated particle emission region is seen to increase significantly with the particle multiplicity of the event.
Yields of prompt and non-prompt J/ψ, as well as Υ(1S) mesons, are measured by the CMS experiment ... more Yields of prompt and non-prompt J/ψ, as well as Υ(1S) mesons, are measured by the CMS experiment via their µ + µ − decays in PbPb and pp collisions at √ s NN = 2.76 TeV for quarkonium rapidity |y| < 2.4. Differential cross sections and nuclear modification factors are reported as functions of y and transverse momentum p T , as well as collision centrality. For prompt J/ψ with relatively high p T (6.5 < p T < 30 GeV/c), a strong, centrality-dependent suppression is observed in PbPb collisions, compared to the yield in pp collisions scaled by the number of inelastic nucleon-nucleon collisions.
We present a measurement of the ratio of positive to negative muon fluxes from cosmic ray interac... more We present a measurement of the ratio of positive to negative muon fluxes from cosmic ray interactions in the atmosphere, using data collected by the CMS detector both at ground level and in the underground experimental cavern at the CERN LHC. Muons were detected in the momentum range from 5 GeV/c to 1 TeV/c. The surface flux ratio is measured to be 1.2766 ± 0.0032 (stat.) ± 0.0032 (syst.), independent of the muon momentum, below 100 GeV/c. This is the most precise measurement to date. At higher momenta the data are consistent with an increase of the charge ratio, in agreement with cosmic ray shower models and compatible with previous measurements by deep-underground experiments.
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