2,547 research outputs found
Gate control of sensory neurotransmission in peripheral ganglia by proprioceptive sensory neurons
Melzak and Wall's gate control theory proposed that innocuous input into the dorsal horn of the spinal cord represses pain-inducing nociceptive input. Here we show that input from proprioceptive parvalbumin-expressing sensory neurons tonically represses nociceptor activation within dorsal root ganglia. Deletion of parvalbumin-positive sensory neurons leads to enhanced nociceptor activity measured with GCaMP3, increased input into wide dynamic range neurons of the spinal cord and increased acute and spontaneous pain behaviour, as well as potentiated innocuous sensation. Parvalbumin-positive sensory neurons express the enzymes and transporters necessary to produce vesicular GABA that is known to be released from depolarized somata. These observations support the view that gate control mechanisms occur peripherally within dorsal root ganglia
Transverse-momentum and pseudorapidity distributions of charged hadrons in pp collisions at sâ=0.9 and 2.36 TeV
This is the publisher's version, also available electronically from http://link.springer.com/article/10.1007%2FJHEP02%282010%29041.Measurements of inclusive charged-hadron transverse-momentum and pseudorapidity distributions are presented for proton-proton collisions at sâ=0.9 and 2.36 TeV. The data were collected with the CMS detector during the LHC commissioning in December 2009. For non-single-diffractive interactions, the average charged-hadron transverse momentum is measured to be 0.46 ± 0.01 (stat.) ± 0.01 (syst.) GeV/c at 0.9 TeV and 0.50 ± 0.01 (stat.) ± 0.01 (syst.) GeV/c at 2.36 TeV, for pseudorapidities between --2.4 and +2.4. At these energies, the measured pseudorapidity densities in the central region, dN (ch)/dη|(|η|)<0.5, are 3:48 ± 0:02 (stat.) ± 0.13 (syst.) and 4:47 ± 0:04 (stat.) ± 0.16 (syst.), respectively. The results at 0.9 TeV are in agreement with previous measurements and confirm the expectation of near equal hadron production in p-bar p and pp collisions. The results at 2.36 TeV represent the highest-energy measurements at a particle collider to date
Search for Dijet Resonances in 7 TeV pp Collisions at CMS
This is the publisher's version, also available electronically from http://journals.aps.org/prl/abstract/10.1103/PhysRevLett.105.211801.A search for narrow resonances in the dijet mass spectrum is performed using data corresponding to an integrated luminosity of 2.9ââpb(â1) 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 E6 diquarks, in specific mass intervals. This extends previously published limits on these models
Long-term treatment with egg oral immunotherapy enhances sustained unresponsiveness that persists after cessation of therapy
We previously reported results of a randomized, placebo-controlled study of egg oral immunotherapy (eOIT), in which 27.5% of subjects achieved sustained unresponsiveness (SU) after 2 years. Here we report results of treatment through 4 years and long-term follow-up
Measurement of the W-boson helicity in top-quark decays from tt-bar production in lepton+jets events in pp collisions at sâ=7 TeV
This is the publisher's version, also available electronically from http://link.springer.com/article/10.1007%2FJHEP10%282013%29167.The W-boson helicity fractions in top-quark decays are measured with tt-bar events in the lepton+jets final state, using proton-proton collisions at a centre-of-mass energy of 7 TeV, collected in 2011 with the CMS detector at the LHC. The data sample corresponds to an integrated luminosity of 5.0 fb(â1). The measured fractions of longitudinal, left-, and right-handed helicity are F 0 = 0.682 ± 0.030 (stat.) ± 0.033 (syst.), F L = 0.310 ± 0.022 (stat.) ± 0.022 (syst.), and F R = 0.008 ± 0.012 (stat.) ± 0.014 (syst.), consistent with the standard model predictions. The measured fractions are used to probe the existence of anomalous Wtb couplings. Exclusion limits on the real components of the anomalous couplings g L , g R are also derived
Measurement of the Î(0)(b) lifetime in pp collisions at sâ=7 TeV
This is the publisher's version, also available electronically from http://link.springer.com/article/10.1007%2FJHEP07%282013%29163.A measurement of the Î(0)(b) lifetime using the decay Î(0)(b)âJ/ÏÎ in protonproton collisions at sâ=7 TeV is presented. The data set, corresponding to an integrated luminosity of about 5 fb(â1), was recorded with the CMS experiment at the Large Hadron Collider using triggers that selected dimuon events in the J/Ï mass region. The Î(0)(b) lifetime is measured to be 1.503 ± 0.052 (stat.) ± 0.031 (syst.) ps
Observation of long-range, near-side angular correlations in proton-proton collisions at the LHC
This is the publisher's version, also available electronically from http://link.springer.com/article/10.1007%2FJHEP09%282010%29091.Results on two-particle angular correlations for charged particles emitted in proton-proton collisions at center-of-mass energies of 0.9, 2.36, and 7 TeV are presented, using data collected with the CMS detector over a broad range of pseudorapidity (η) and azimuthal angle (Ï). Short-range correlations in Îη, which are studied in minimum bias events, are characterized using a simple âindependent clusterâ parametrization in order to quantify their strength (cluster size) and their extent in η (cluster decay width). Long-range azimuthal correlations are studied differentially as a function of charged particle multiplicity and particle transverse momentum using a 980 nb(â1) data set at 7 TeV. In high multiplicity events, a pronounced structure emerges in the two-dimensional correlation function for particle pairs with intermediate p T of 1â3 GeV/c, 2.0 < |Îη| < 4.8 and ÎÏ â 0. This is the first observation of such a long-range, near-side feature in two-particle correlation functions in pp or pp-bar collisions
Measurement of neutral strange particle production in the underlying event in proton-proton collisions at sâ=7ââTeV
This is the publisher's version, also available electronically from http://journals.aps.org/prd/abstract/10.1103/PhysRevD.88.052001.Measurements are presented of the production of primary K(0)(S) and Î particles in proton-proton collisions at sâ=7ââTeV in the region transverse to the leading charged-particle jet in each event. The average multiplicity and average scalar transverse momentum sum of K(0)(S) and Î particles measured at pseudorapidities |η|<2 rise with increasing charged-particle jet p(T) in the range 1â10ââGeV/c and saturate in the region 10â50ââGeV/c. The rise and saturation of the strange-particle yields and transverse momentum sums in the underlying event are similar to those observed for inclusive charged particles, which confirms the impact-parameter picture of multiple parton interactions. The results are compared to recent tunes of the pythia Monte Carlo event generator. The pythia simulations underestimate the data by 15%â30% for K(0)(S) mesons and by about 50% for Î baryons, a deficit similar to that observed for the inclusive strange-particle production in non-single-diffractive proton-proton collisions. The constant strange- to charged-particle activity ratios with respect to the leading jet p(T) and similar trends for mesons and baryons indicate that the multiparton-interaction dynamics is decoupled from parton hadronization, which occurs at a later stage
Search for Top Squarks in R-Parity-Violating Supersymmetry Using Three or More Leptons and b-Tagged Jets
This is the publisher's version, also available electronically from http://journals.aps.org/prl/abstract/10.1103/PhysRevLett.111.221801.A search for anomalous production of events with three or more isolated leptons and bottom-quark jets produced in pp collisions at sâ=8ââTeV is presented. The analysis is based on a data sample corresponding to an integrated luminosity of 19.5ââfb(â1) collected by the CMS experiment at the LHC in 2012. No excess above the standard model expectations is observed. The results are interpreted in the context of supersymmetric models with signatures that have low missing transverse energy arising from light top-squark pair production with R-parity-violating decays of the lightest supersymmetric particle. In two models with different R-parity-violating couplings, top squarks are excluded below masses of 1020 GeV and 820 GeV when the lightest supersymmetric particle has a mass of 200 GeV
Search for the standard model Higgs boson produced in association with a top-quark pair in pp collisions at the LHC
This is the publisher's version, also available electronically from http://link.springer.com/article/10.1007%2FJHEP05%282013%29145.A search for the standard model Higgs boson produced in association with a top-quark pair is presented using data samples corresponding to an integrated luminosity of 5.0 fb(â1) (5.1 fb(â1)) collected in pp collisions at the center-of-mass energy of 7 TeV (8 TeV). Events are considered where the top-quark pair decays to either one lepton+jets (tt-barââÎœqq-bar âČbb-bar) or dileptons (tt-barââ(+)Îœâ(â)Îœ-bar bb-bar) , â being an electron or a muon. The search is optimized for the decay mode Hâbb-bar . The largest background to the tt-barH signal is top-quark pair production with additional jets. Artificial neural networks are used to discriminate between signal and background events. Combining the results from the 7 TeV and 8 TeV samples, the observed (expected) limit on the cross section for Higgs boson production in association with top-quark pairs for a Higgs boson mass of 125 GeV is 5.8 (5.2) times the standard model expectation
- âŠ