238 research outputs found

    Dataset after seven years simulating hybrid energy systems with Homer Legacy

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    Homer Legacy software is a well-known software for simulation of small hybrid systems that can be used for both design and research. This dataset is a set of files generated by Homer Legacy bringing the simulation results of hybrid energy systems over the last seven years, as a consequence of the research work led by Dr. Alexandre Beluco, Federal University of Rio Grande do Sul, in southern Brazil. The data correspond to twelve papers published in the last seven years. Two of them describe hydro PV hybrid systems with photovoltaic panels operating on the water surface of reservoirs. One of these twelve papers suggests the modeling of hydropower plants with reservoirs and the other the modeling of pumped hydro storage, and a third still uses these models in a place that could receive both the two types of hydroelectric power plant. The other simulated hybrid systems include wind turbines, diesel generators, batteries, among other components. This data article describes the files that integrate this dataset and the papers that have been published presenting the hybrid systems under study and discussing the results. The files that make up this dataset are available on Mendeley Data repository at https://doi.org/10.17632/ybxsttf2by.2

    Search for a High-Mass Diphoton State and Limits on Randall-Sundrum Gravitons at CDF

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    We have performed a search for new particles which decay to two photons using 1.2/fb of integrated luminosity from p-pbar collisions at sqrt(s) = 1.96 TeV collected using the CDF II Detector at the Fermilab Tevatron. We find the diphoton mass spectrum to be in agreement with the standard model expectation, and set limits on the cross section times branching ratio for the Randall-Sundrum graviton, as a function of diphoton mass. We subsequently derive lower limits for the graviton mass of 230 GeV/c2 and 850 GeV/c2, at the 95% confidence level, for coupling parameters (k/M_Pl) of 0.01 and 0.1 respectively.Comment: submitted to Phys. Rev. Let

    Measurement of the Helicity Fractions of W Bosons from Top Quark Decays Using Fully Reconstructed top-antitop Events with CDF II

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    We present a measurement of the fractions F_0 and F_+ of longitudinally polarized and right-handed W bosons in top quark decays using data collected with the CDF II detector. The data set used in the analysis corresponds to an integrated luminosity of approximately 318 pb -1. We select ttbar candidate events with one lepton, at least four jets, and missing transverse energy. Our helicity measurement uses the decay angle theta*, which is defined as the angle between the momentum of the charged lepton in the W boson rest frame and the W momentum in the top quark rest frame. The cos(theta*) distribution in the data is determined by full kinematic reconstruction of the ttbar candidates. We find F_0 = 0.85 +0.15 -0.22 (stat) +- 0.06 (syst) and F_+ = 0.05 +0.11 -0.05 (stat) +- 0.03 (syst), which is consistent with the standard model prediction. We set an upper limit on the fraction of right-handed W bosons of F_+ < 0.26 at the 95% confidence level.Comment: 11 pages, 2 figures, submitted to Phys. Rev.

    Measurement of the ttbar Production Cross Section in ppbar Collisions at sqrt(s) = 1.96 TeV

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    We present a measurement of the top quark pair production cross section in ppbar collisions at sqrt(s)=1.96 TeV using 318 pb^{-1} of data collected with the Collider Detector at Fermilab. We select ttbar decays into the final states e nu + jets and mu nu + jets, in which at least one b quark from the t-quark decays is identified using a secondary vertex-finding algorithm. Assuming a top quark mass of 178 GeV/c^2, we measure a cross section of 8.7 +-0.9 (stat) +1.1-0.9 (syst) pb. We also report the first observation of ttbar with significance greater than 5 sigma in the subsample in which both b quarks are identified, corresponding to a cross section of 10.1 +1.6-1.4(stat)+2.0-1.3 (syst) pb.Comment: Accepted for publication in Physics Review Letters, 7 page

    Top quark mass measurement using the template method at CDF

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    We present a measurement of the top quark mass in the lepton+jets and dilepton channels of ttˉt\bar{t} decays using the template method. The data sample corresponds to an integrated luminosity of 5.6 fb1^{-1} of ppˉp\bar{p} collisions at Tevatron with s=1.96\sqrt{s}=1.96 TeV, collected with the CDF II detector. The measurement is performed by constructing templates of three kinematic variables in the lepton+jets and two kinematic variables in the dilepton channel. The variables are two reconstructed top quark masses from different jets-to-quarks combinations and the invariant mass of two jets from the WW decay in the lepton+jets channel, and a reconstructed top quark mass and mT2m_{T2}, a variable related to the transverse mass in events with two missing particles, in the dilepton channel. The simultaneous fit of the templates from signal and background events in the lepton+jets and dilepton channels to the data yields a measured top quark mass of Mtop=172.1±1.1(stat)±0.9(syst).M_{top} = 172.1 \pm 1.1(stat) \pm 0.9(syst).Comment: submitted to Phys. Rev.

    Measurement of the Inclusive Jet Cross Section in ppbar Interactions at sqrt{s}=1.96 TeV Using a Cone-based Jet Algorithm

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    We present a measurement of the inclusive jet cross section in ppbar interactions at sqrt{s}=1.96 TeV using 385 pb^{-1} of data collected with the CDF II detector at the Fermilab Tevatron. The results are obtained using an improved cone-based jet algorithm (Midpoint). The data cover the jet transverse momentum range from 61 to 620 GeV/c, extending the reach by almost 150 GeV/c compared with previous measurements at the Tevatron. The results are in good agreement with next-to-leading order perturbative QCD predictions using the CTEQ6.1M parton distribution functions.Comment: 19 pages, 2 figures, 1 tabl

    Observation and Mass Measurement of the Baryon Ξb\Xi^-_b

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    We report the observation and measurement of the mass of the bottom, strange baryon Ξb\Xi^-_b through the decay chain ΞbJ/ψΞ\Xi^-_b \to J/\psi \Xi^-, where J/ψμ+μJ/\psi \to \mu^+ \mu^-, ΞΛπ\Xi^- \to \Lambda \pi^-, and Λpπ\Lambda \to p \pi^-. Evidence for observation is based on a signal whose probability of arising from the estimated background is 6.6 x 10^{-15}, or 7.7 Gaussian standard deviations. The Ξb\Xi^-_b mass is measured to be 5792.9±2.55792.9\pm 2.5 (stat.) ±1.7\pm 1.7 (syst.) MeV/c2c^2.Comment: Minor text changes for the second version. Accepted by Phys. Rev. Let

    Search for New Particles Leading to Z+jets Final States in ppˉp\bar{p} Collisions at s=1.96\sqrt{s}=1.96 TeV

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    We present the results of a search for new particles that lead to a \Z boson plus jets in ppˉp\bar{p} collisions at s=1.96\sqrt{s}=1.96 TeV using the Collider Detector at Fermilab (CDF II). A data sample with a luminosity of 1.06 \ifb\ collected using \Z boson decays to eeee and μμ\mu\mu is used. We describe a completely data-based method to predict the dominant background from standard-model \Z+jet events. This method can be similarly applied to other analyses requiring background predictions in multi-jet environments, as shown when validating the method by predicting the background from WW+jets in \ttbar production. No significant excess above the background prediction is observed, and a limit is set using a fourth generation quark model to quantify the acceptance. Assuming BR(bbZ)=100BR(b' \to b\Z) = 100% and using a leading-order calculation of the bb' cross section, bb' quark masses below 268 \gev/c^2 are excluded at 95% confidence level.Comment: To be submitted to PR

    Polarizations of J/psi and psi(2S) Mesons Produced in ppbar Collisions at 1.96 TeV

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    We have measured the polarizations of \jpsi and \psiprime mesons as functions of their transverse momentum \pt when they are produced promptly in the rapidity range y<0.6|y|<0.6 with \pt \geq 5 \pgev. The analysis is performed using a data sample with an integrated luminosity of about 800 \ipb collected by the CDF II detector. For both vector mesons, we find that the polarizations become increasingly longitudinal as \pt increases from 5 to 30 \pgev. These results are compared to the predictions of nonrelativistic quantum chromodynamics and other contemporary models. The effective polarizations of \jpsi and \psiprime mesons from BB-hadron decays are also reported.Comment: 8 pages, 7 figures, published in Physical Review Letter

    First Measurement of the W Boson Mass in Run II of the Tevatron

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    We present a measurement of the W boson mass using 200/pb of data collected in pbar p collisions at sqrt(s) = 1.96 TeV by the CDF II detector at Run II of the Fermilab Tevatron. With a sample of 63964 W -> e nu candidates and 51128 W -> mu nu candidates, we measure M_W = (80413 +- 34 (stat) +- 34 (syst) = 80413 +- 48) MeV/c^2. This is the most precise single measurement of the W boson mass to date.Comment: published version in PR
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