Study of double parton scattering using W + 2-jet events in proton-proton collisions at √s = 7 TeV

Double parton scattering is investigated in proton-proton collisions at √s = 7 TeV where the final state includes a W boson, which decays into a muon and a neutrino, and two jets. The data sample corresponds to an integrated luminosity of 5 fb−1, collected with the CMS detector at the LHC. Observables sensitive to double parton scattering are investigated after being corrected for detector effects and selection efficiencies. The fraction of W + 2-jet events due to double parton scattering is measured to be 0.055 ± 0.002 (stat.) ± 0.014 (syst.). The effective cross section, σeff, characterizing the effective transverse area of hard partonic interactions in collisions between protons is measured to be 20.7 ± 0.8 (stat.) ± 6.6 (syst.)mb

Measurement of the triple-differential cross section for photon + jets production in proton-proton collisions at √s = 7 TeV

A measurement of the triple-differential cross section, d3σ/(dpTϒ dɳϒ dɳjet), in photon+jets final states using a data sample from proton-proton collisions at√s = 7TeV is presented. This sample corresponds to an integrated luminosity of 2.14 fb−1 collected bythe CMS detector at the LHC. Photons and jets are reconstructed within a pseudorapidity range of |ɳ| \u3c 2.5, and are required to have transverse momenta in the range 40 \u3c pjetT \u3c 300 GeV and pjetT \u3e 30 GeV, respectively. The measurements are compared to theoretical predictions from the sherpa leading-order QCD Monte Carlo event generator and the next-to-leading-order perturbative QCD calculation from jetphox. The predictions are found to be consistent with the data over most of the examined kinematic region

Excess mortality in Spain during transmission of pandemic influenza in 2009

Fundamento: El sistema español de monitorización de la mortalidad y el "Programa Europeo de monitorización de excesos de mortalidad para la acción en salud pública" detectaron dos excesos de mortalidad en España en noviembre y diciembre de 2009. El objetivo de este trabajo es valorar su posible asociación con la transmisión de gripe pandémica. Métodos: Se analizó la evolución de la mortalidad en España en los meses citados utilizando métodos de análisis de series temporales basados en las series históricas de mortalidad y se comparó en el tiempo con la transmisión de gripe. Resultados: La mortalidad observada en la población total fue mayor de lo esperado en dos periodos: semanas 46-47/2009 con 5,75% de exceso y las semanas 51-52/2009 con 7,35% de exceso. También se registró un exceso de mortalidad en niños de 5 a 14 años en las semanas 46-48/2009 con 41 defunciones vs las 21 esperadas. El exceso de mortalidad en noviembre fue concomitante con las mayores tasas de gripe. El exceso de diciembre se observó 5 semanas después del pico de gripe y coincidió con un descenso dramático de las temperaturas. El virus sincitial respiratorio y los accidentes de tráfico fueron descartados como factores asociados. Conclusiones: Mientras que las temperaturas podrían explicar la mayoría del exceso de mortalidad observado en diciembre, ningún factor por si solo podría explicar el exceso de noviembre. BACKGROUND: The Spanish daily mortality monitoring system and the program «European monitoring of excess mortality for public health action» found two excesses of mortality in Spain in November and December 2009. METHODS: We analyzed the evolution of mortality in Spain during those months using time-series analysis methods based on historical mortality series and compared it in the time with influenza transmission. RESULTS: Observed mortality for the total population was higher than expected in two periods: weeks 46-47/2009 with 5.75% excess and weeks 51-52/2009 with 7.35% excess. Observed mortality higher than expected, was also observed in children 5-14 years old during weeks 46-48/2009 with 41 deaths vs 21 expected. Exces mortality in November occurred before or was concomitant with highest influenza incidence rates. Excess mortality in December occurred five weeks after the influenza incidence peak and along with dramatic drop in temperatures. RSV and traffic accidents were ruled out as factor associated to these excesses. CONCLUSIONS: While temperatures could explain most of the excess mortality observed in December, no single factor could be associated with observed excess mortality in November

Functional characterization of a melon alcohol acyl-transferase gene family involved in the biosynthesis of ester volatiles. Identification of the crucial role of a threonine residue for enzyme activity

Volatile esters, a major class of compounds contributing to the aroma of many fruit, are synthesized by alcohol acyl-transferases (AAT). We demonstrate here that, in Charentais melon (Cucumis melo var. cantalupensis), AAT are encoded by a gene family of at least four members with amino acid identity ranging from 84% (Cm-AAT1/Cm-AAT2) and 58% (Cm-AAT1/Cm-AAT3) to only 22% (Cm-AAT1/Cm-AAT4). All encoded proteins, except Cm-AAT2, were enzymatically active upon expression in yeast and show differential substrate preferences. Cm-AAT1 protein produces a wide range of short and long-chain acyl esters but has strong preference for the formation of E-2-hexenyl acetate and hexyl hexanoate. Cm-AAT3 also accepts a wide range of substrates but with very strong preference for producing benzyl acetate. Cm-AAT4 is almost exclusively devoted to the formation of acetates, with strong preference for cinnamoyl acetate. Site directed mutagenesis demonstrated that the failure of Cm-AAT2 to produce volatile esters is related to the presence of a 268-alanine residue instead of threonine as in all active AAT proteins. Mutating 268-A into 268-T of Cm-AAT2 restored enzyme activity, while mutating 268-T into 268-A abolished activity of Cm-AAT1. Activities of all three proteins measured with the prefered substrates sharply increase during fruit ripening. The expression of all Cm-AAT genes is up-regulated during ripening and inhibited in antisense ACC oxidase melons and in fruit treated with the ethylene antagonist 1-methylcyclopropene (1-MCP), indicating a positive regulation by ethylene. The data presented in this work suggest that the multiplicity of AAT genes accounts for the great diversity of esters formed in melon

Search for resonant and nonresonant Higgs boson pair production in the bb\u3ci\u3elvlv\u3c/i\u3e final state in proton-proton collisions at √s = 13 TeV

Searches for resonant and nonresonant pair-produced Higgs bosons (HH) decaying respectively into lvlv, through either W or Z bosons, and bb are presented. The analyses are based on a sample of proton-proton collisions at √s = 13TeV, collected by the CMS experiment at the LHC, corresponding to an integrated luminosity of 35.9 fb-1. Data and predictions from the standard model are in agreement within uncertainties. For the standard model HH hypothesis, the data exclude at 95% confidence level a product of the production cross section and branching fraction larger than 72 fb, corresponding to 79 times the standard model prediction. Constraints are placed on different scenarios considering anomalous couplings, which could affect the rate and kinematics of HH production. Upper limits at 95% confidence level are set on the production cross section of narrow width spin-0 and spin-2 particles decaying to Higgs boson pairs, the latter produced with minimal gravity-like coupling

CMS: Search for heavy resonances decaying to a top quark and a bottom quark in the lepton+jets final state in proton–proton collisions at 13TeV

A search is presented for narrow heavy resonances decaying to a top quark and a bottom quark using data collected by the CMS experiment at √s=13TeV in 2016. The data set analyzed corresponds to an integrated luminosity of 35.9fb−1. Final states that include a single lepton (e, μ), multiple jets, and missing transverse momentum are analyzed. No evidence is found for the production of a W\u27 boson, and the production of right-handed W\u27 bosons is excluded at 95% confidence level for masses up to 3.6TeV depending on the scenario considered. Exclusion limits for W\u27 bosons are also presented as a function of their coupling strength to left-and right-handed fermions. These limits on a W\u27 boson decaying via a top and a bottom quark are the most stringent published to date

Measurements of tt cross sections in association with b jets and inclusive jets and their ratio using dilepton final states in pp collisions at √s=13 TeV

The cross sections for the production of ttbb and ttjj events and their ratio σttbb/σttjj are measured using data corresponding to an integrated luminosity of 2.3fb−1 collected in pp collisions at √s = 13 TeV with the CMS detector at the LHC. Events with two leptons (e or μ) and at least four reconstructed jets, including at least two identified as b quark jets, in the final state are selected. In the full phase space, the measured ratio is 0.022 ± 0.003(stat) ± 0.006(syst), the cross section σttbb is 4.0 ± 0.6(stat) ±1.3(syst) pb and σttjj is 184 ± 6(stat) ± 33(syst) pb. The measurements are compared with the standard model expectations obtained from a powheg simulation at next-to-leading-order interfaced with pythia

CMS: Search for lepton flavour violating decays of heavy resonances and quantum black holes to an eμ pair in proton–proton collisions at √s = 8 TeV

A search for narrow resonances decaying to an electron and a muon is presented. The eμ mass spectrum is also investigated for non-resonant contributions from the production of quantum black holes (QBHs). The analysis is performed using data corresponding to an integrated luminosity of 19.7 fb−1 collected in proton-proton collisions at a centre-of-mass energy of 8 TeV with the CMS detector at the LHC. With no evidence for physics beyond the standard model in the invariant mass spectrum of selected eμ pairs, upper limits are set at 95% confidence level on the product of cross section and branching fraction for signals arising in theories with charged lepton flavour violation. In the search for narrow resonances, the resonant production of a τ sneutrino in R-parity violating supersymmetry is considered. The τ sneutrino is excluded for masses below 1.28 TeV for couplings λ132 = λ231 = λ\u27311 = 0.01, and below 2.30 TeV for λ132 = λ231 = 0.07 and λ\u27311 = 0.11. These are the most stringent limits to date from direct searches at high-energy colliders. In addition, the resonance searches are interpreted in terms of a model with heavy partners of the Z boson and the photon. In a framework of TeV-scale quantum gravity based on a renormalization of Newton’s constant, the search for non-resonant contributions to the eμmass spectrum excludes QBH production below a threshold mass Mth of 1.99 TeV. In models that invoke extra dimensions, the bounds range from 2.36 TeV for one extra dimension to 3.63 TeV for six extra dimensions. This is the first search for QBHs decaying into the eμ final state