4,210 research outputs found

    Monitoreo de la frecuencia cardiaca como indicador de la intensidad del entrenamiento en el futbolista profesional a 2 600 m sobre el nivel del mar

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    Resumen Introducción: Con el objetivo de analizar el comportamiento de la frecuencia cardiaca como indicador de la intensidad del entrenamiento en el futbolista profesional a 2 600 m sobre el nivel del mar. Materiales y métodos: Se realizó un estudio longitudinal, prospectivo de la temporada apertura 2017 y clausura 2018 del fútbol mexicano, con un análisis estadístico descriptivo con medidas de tendencia central y de dispersión, así como intervalos de confianza en un análisis de 2 328 monitoreos de la frecuencia cardiaca y distancia recorrida con el sistema de seguimiento por GPS Polar Team Pro y 111 monitoreos ambientales, con una duración aproximada de 120 minutos por sesión de entrenamiento. Resultados: Se llevaron a cabo 2 328 monitoreos con registros de frecuencia cardiaca en reposo, variabilidad de la frecuencia cardiaca (vfc), frecuencia cardiaca durante el entrenamiento y la recuperación; con 111 registros ambientales. Algunas de las variables propias del monitoreo de la frecuencia cardiaca durante el entrenamiento por la dinámica del mismo, como lo es, no seguir indicaciones o impuntualidad por el deportista; así como los tiempos propios marcados por el entrenador, falla del registro por desconexión del sensor, entre otras, hacen que algunos registros no sean valorables. Conclusiones: La frecuencia cardiaca de reposo permanece en los parámetros normales, la frecuencia cardiaca media de entrenamiento se encuentra en zona 2 de control de peso entre el 60-70% de la frecuencia cardiaca máxima, y la frecuencia cardiaca máxima de esfuerzo dentro de la zona 5 de alta intensidad, mientras que la frecuencia cardiaca mínima se ubica por debajo de la zona 1 de actividad regenerativa que va de un 50-60% de la frecuencia cardiaca máxima. Abstract Introduction: The purpose of this study is to analyze the behavior of the cardiac variability as an indicator of the training intensity in football players at 2600mts altitude above sea level. Methods: This was a longitudinal and prospective study of the 2017-2018 Mexican football seasons, with a descriptive analysis and central tendency on dispersion measurements as confidence intervals. These intervals consisted of 2328 heart rate cardiac monitorizations,traveled distance with the Polar Team Pro GPS tracking system and 111 environmental monitorizations, with each training session length of 120 minutes approximately. Results: After making 2328 monitorizations the following measures were obtained: resting heart rate, heart rate variability (hrv), heart rate during training and recovery sessions amongst 111 environmental registrations. Some variables of the heart rate monitorization records during the training session couldn´t be measured or valued such as not following instructions, football players running late, the coach training marked times, and the cardiac monitor connection errors. Conclusions: The resting heart rate is between the normal parameters. The medium heart rate is between 60-70% of the maximum heart rate of the second zone of weight control. The maximum heart rate posterior to the effort is in the fifth zone of high intensity, meanwhile the minimum heart rate is below the first zone of regenerative activity that corresponds from 50-60% of the maximum heart rate

    Charge separation relative to the reaction plane in Pb-Pb collisions at sNN=2.76\sqrt{s_{\rm NN}}= 2.76 TeV

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    Measurements of charge dependent azimuthal correlations with the ALICE detector at the LHC are reported for Pb-Pb collisions at sNN=2.76\sqrt{s_{\rm NN}} = 2.76 TeV. Two- and three-particle charge-dependent azimuthal correlations in the pseudo-rapidity range η<0.8|\eta| < 0.8 are presented as a function of the collision centrality, particle separation in pseudo-rapidity, and transverse momentum. A clear signal compatible with a charge-dependent separation relative to the reaction plane is observed, which shows little or no collision energy dependence when compared to measurements at RHIC energies. This provides a new insight for understanding the nature of the charge dependent azimuthal correlations observed at RHIC and LHC energies.Comment: 12 pages, 3 captioned figures, authors from page 2 to 6, published version, figures at http://aliceinfo.cern.ch/ArtSubmission/node/286

    Search for the standard model Higgs boson in the H to ZZ to 2l 2nu channel in pp collisions at sqrt(s) = 7 TeV

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    A search for the standard model Higgs boson in the H to ZZ to 2l 2nu decay channel, where l = e or mu, in pp collisions at a center-of-mass energy of 7 TeV is presented. The data were collected at the LHC, with the CMS detector, and correspond to an integrated luminosity of 4.6 inverse femtobarns. No significant excess is observed above the background expectation, and upper limits are set on the Higgs boson production cross section. The presence of the standard model Higgs boson with a mass in the 270-440 GeV range is excluded at 95% confidence level.Comment: Submitted to JHE

    Transverse sphericity of primary charged particles in minimum bias proton-proton collisions at s=0.9\sqrt{s}=0.9, 2.76 and 7 TeV

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    Measurements of the sphericity of primary charged particles in minimum bias proton--proton collisions at s=0.9\sqrt{s}=0.9, 2.76 and 7 TeV with the ALICE detector at the LHC are presented. The observable is linearized to be collinear safe and is measured in the plane perpendicular to the beam direction using primary charged tracks with pT0.5p_{\rm T}\geq0.5 GeV/c in η0.8|\eta|\leq0.8. The mean sphericity as a function of the charged particle multiplicity at mid-rapidity (NchN_{\rm ch}) is reported for events with different pTp_{\rm T} scales ("soft" and "hard") defined by the transverse momentum of the leading particle. In addition, the mean charged particle transverse momentum versus multiplicity is presented for the different event classes, and the sphericity distributions in bins of multiplicity are presented. The data are compared with calculations of standard Monte Carlo event generators. The transverse sphericity is found to grow with multiplicity at all collision energies, with a steeper rise at low NchN_{\rm ch}, whereas the event generators show the opposite tendency. The combined study of the sphericity and the mean pTp_{\rm T} with multiplicity indicates that most of the tested event generators produce events with higher multiplicity by generating more back-to-back jets resulting in decreased sphericity (and isotropy). The PYTHIA6 generator with tune PERUGIA-2011 exhibits a noticeable improvement in describing the data, compared to the other tested generators.Comment: 21 pages, 9 captioned figures, 3 tables, authors from page 16, published version, figures from http://aliceinfo.cern.ch/ArtSubmission/node/308

    A note on comonotonicity and positivity of the control components of decoupled quadratic FBSDE

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    In this small note we are concerned with the solution of Forward-Backward Stochastic Differential Equations (FBSDE) with drivers that grow quadratically in the control component (quadratic growth FBSDE or qgFBSDE). The main theorem is a comparison result that allows comparing componentwise the signs of the control processes of two different qgFBSDE. As a byproduct one obtains conditions that allow establishing the positivity of the control process.Comment: accepted for publicatio

    Measurement of the cross-section and charge asymmetry of WW bosons produced in proton-proton collisions at s=8\sqrt{s}=8 TeV with the ATLAS detector

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    This paper presents measurements of the W+μ+νW^+ \rightarrow \mu^+\nu and WμνW^- \rightarrow \mu^-\nu cross-sections and the associated charge asymmetry as a function of the absolute pseudorapidity of the decay muon. The data were collected in proton--proton collisions at a centre-of-mass energy of 8 TeV with the ATLAS experiment at the LHC and correspond to a total integrated luminosity of 20.2~\mbox{fb^{-1}}. The precision of the cross-section measurements varies between 0.8% to 1.5% as a function of the pseudorapidity, excluding the 1.9% uncertainty on the integrated luminosity. The charge asymmetry is measured with an uncertainty between 0.002 and 0.003. The results are compared with predictions based on next-to-next-to-leading-order calculations with various parton distribution functions and have the sensitivity to discriminate between them.Comment: 38 pages in total, author list starting page 22, 5 figures, 4 tables, submitted to EPJC. All figures including auxiliary figures are available at https://atlas.web.cern.ch/Atlas/GROUPS/PHYSICS/PAPERS/STDM-2017-13

    Search for chargino-neutralino production with mass splittings near the electroweak scale in three-lepton final states in √s=13 TeV pp collisions with the ATLAS detector

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    A search for supersymmetry through the pair production of electroweakinos with mass splittings near the electroweak scale and decaying via on-shell W and Z bosons is presented for a three-lepton final state. The analyzed proton-proton collision data taken at a center-of-mass energy of √s=13  TeV were collected between 2015 and 2018 by the ATLAS experiment at the Large Hadron Collider, corresponding to an integrated luminosity of 139  fb−1. A search, emulating the recursive jigsaw reconstruction technique with easily reproducible laboratory-frame variables, is performed. The two excesses observed in the 2015–2016 data recursive jigsaw analysis in the low-mass three-lepton phase space are reproduced. Results with the full data set are in agreement with the Standard Model expectations. They are interpreted to set exclusion limits at the 95% confidence level on simplified models of chargino-neutralino pair production for masses up to 345 GeV

    Search for anomalous t t-bar production in the highly-boosted all-hadronic final state

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    A search is presented for a massive particle, generically referred to as a Z', decaying into a t t-bar pair. The search focuses on Z' resonances that are sufficiently massive to produce highly Lorentz-boosted top quarks, which yield collimated decay products that are partially or fully merged into single jets. The analysis uses new methods to analyze jet substructure, providing suppression of the non-top multijet backgrounds. The analysis is based on a data sample of proton-proton collisions at a center-of-mass energy of 7 TeV, corresponding to an integrated luminosity of 5 inverse femtobarns. Upper limits in the range of 1 pb are set on the product of the production cross section and branching fraction for a topcolor Z' modeled for several widths, as well as for a Randall--Sundrum Kaluza--Klein gluon. In addition, the results constrain any enhancement in t t-bar production beyond expectations of the standard model for t t-bar invariant masses larger than 1 TeV.Comment: Submitted to the Journal of High Energy Physics; this version includes a minor typo correction that will be submitted as an erratu
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