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Measurement of the underlying event in the Drell–Yan process in proton–proton collisions at √s = 7 TeV
(2012)The European Physical Journal CA measurement of the underlying event (UE) activity in proton–proton collisions at a center-of-mass energy of 7 TeV is performed using Drell–Yan events in a data sample corresponding to an integrated luminosity of 2.2 fb−1, collected by the CMS experiment at the LHC. The activity measured in the muonic final state (qq¯¯¯→μ+μ−) is corrected to the particle level and compared with the predictions of various Monte Carlo generators and ...Journal Article -
Study of high-pT charged particle suppression in PbPb compared to pp collisions at √sNN=2.76 TeV
(2012)The European Physical Journal CThe transverse momentum spectra of charged particles have been measured in pp and PbPb collisions at sNN−−−−√=2.76 TeV by the CMS experiment at the LHC. In the transverse momentum range p T=5–10 GeV/c, the charged particle yield in the most central PbPb collisions is suppressed by up to a factor of 7 compared to the pp yield scaled by the number of incoherent nucleon–nucleon collisions. At higher p T, this suppression is significantly ...Journal Article -
Study of the inclusive production of charged pions, kaons, and protons in pp collisions at √s=0.9, 2.76, and 7 TeV
(2012)The European Physical Journal CSpectra of identified charged hadrons are measured in pp collisions at the LHC for s√=0.9,2.76, and 7 TeV. Charged pions, kaons, and protons in the transverse-momentum range p T≈0.1–1.7 GeV/c and for rapidities |y|<1 are identified via their energy loss in the CMS silicon tracker. The average p T increases rapidly with the mass of the hadron and the event charged-particle multiplicity, independently of the center-of-mass energy. The fully ...Journal Article -
Double real radiation corrections to tt¯ production at the LHC: the gg → tt¯qq¯ channel
(2012)Journal of High Energy PhysicsWe present the double real radiation contributions to the tt¯ hadronic production cross section stemming from the partonic process gg→tt¯qq¯. We explicitly construct the antenna subtraction terms for this gluon-gluon initiated process starting from the double soft behaviour of the double real radiation matrix elements using soft currents. Those subtraction terms, given in leading and subleading colour contributions, require the use of new ...Journal Article -
Repulsion forces of superplasticizers on ground granulated blast furnace slag in alkaline media, from AFM measurements to rheological properties
(2012)Materiales de ConstrucciónThe electrostatic and steric repulsion induced by different superplasticizers on ground granulated blast furnace slag in alkaline media have been studied. The superplasticizers were sulfonated naphthalene, sulfonated melamine, vinyl copolymer, and polycarboxylate- based admixtures. With these superplasticizers the slag suspensions had negative zeta potentials, ranging from -3 to -10 mV. For the first time the adsorbed layer thicknesses ...Journal Article -
Measurement of inclusive and dijet D* meson cross sections in photoproduction at HERA
(2012)The European Physical Journal CThe inclusive photoproduction of D ∗ mesons and of D ∗-tagged dijets is investigated with the H1 detector at the ep collider HERA. The kinematic region covers small photon virtualities Q 2<2 GeV2 and photon–proton centre-of-mass energies of 100<W γp <285 GeV. Inclusive D ∗ meson differential cross sections are measured for central rapidities |η(D ∗)|<1.5 and transverse momenta p T (D ∗)>1.8 GeV. The heavy quark production process is further ...Journal Article -
Higgs and supersymmetry
(2012)The European Physical Journal CGlobal frequentist fits to the CMSSM and NUHM1 using the MasterCode framework predicted M h ≃119 GeV in fits incorporating the (g−2) μ constraint and ≃126 GeV without it. Recent results by ATLAS and CMS could be compatible with a Standard Model-like Higgs boson around M h ≃125 GeV. We use the previous MasterCode analysis to calculate the likelihood for a measurement of any nominal Higgs mass within the range of 115 to 130 GeV. Assuming a ...Journal Article -
Measurement of beauty and charm photoproduction using semi-muonic decays in dijet events at HERA
(2012)The European Physical Journal CMeasurements of cross sections for beauty and charm events with dijets and a muon in the photoproduction regime at HERA are presented. The data were collected with the H1 detector and correspond to an integrated luminosity of 179 pb−1. Events with dijets of transverse momentum Pjet1T>7 GeV and Pjet2T>6 GeV in the pseudorapidity range −1.5<η jet<2.5 in the laboratory frame are selected in the kinematic region of photon virtuality Q 2<2.5 ...Journal Article -
Measurement of dijet production in diffractive deep-inelastic scattering with a leading proton at HERA
(2012)The European Physical Journal CThe cross section of diffractive deep-inelastic scattering ep→eXp is measured, where the system X contains at least two jets and the leading final state proton is detected in the H1 Forward Proton Spectrometer. The measurement is performed for fractional proton longitudinal momentum loss x ℙ<0.1 and covers the range 0.1<|t|<0.7 GeV2 in squared four-momentum transfer at the proton vertex and 4<Q 2<110 GeV2 in photon virtuality. The ...Journal Article -
Measurement of the azimuthal correlation between the most forward jet and the scattered positron in deep-inelastic scattering at HERA
(2012)The European Physical Journal CDeep-inelastic positron-proton scattering events at low photon virtuality, Q 2, with a forward jet, produced at small angles with respect to the proton beam, are measured with the H1 detector at HERA. A subsample of events with an additional jet in the central region is also studied. For both samples, differential cross sections and normalised distributions are measured as a function of the azimuthal angle difference, Δϕ, between the ...Journal Article