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Study of the Asymmetric Photoproduction of Charmed Mesons using Data from the FOCUS Experiment

Study of the Asymmetric Photoproduction of Charmed Mesons using Data from the FOCUS Experiment

Date: May 1, 2005
Creator: Vazquez-Valencia, Elsa Fabiola & /CINVESTAV, IPN
Description: Using data from the fixed target charm-photoproduction experiment, Fermilab FOCUS/E831, they studied the asymmetric production of the mesons: D{sup 0}, D{sup +} y D{sub s}{sup +}. Even when the asymmetry in the production of charm particles, defined as the ratio between particles and antiparticles, at next leading order in quantum chromodynamics (QCD) is almost zero, in data we observe asymmetries probably associate dto the fragmentation processes. Since these are the less understood phenomena in QCD, the results in the present work could be of great importance to understand them. We found asymmetries in the production of the mesons D{sup +} and D{sup 0} (statistic significant), for the D{sub s}{sup +} we only observed an asymmetry not conclusive. We also report a study of the production asymmetries vs. the kinematic variables: p{sub T}{sup 2} (square transversal momentum of the particles), p{sub L} or p{sub Z} (longitudinal momentum), x{sub F} (Feynman x) and E{sub {gamma}} (photon beam energy).
Contributing Partner: UNT Libraries Government Documents Department
Study of the top quark electric charge at the CDF experiment

Study of the top quark electric charge at the CDF experiment

Date: September 1, 2011
Creator: Bartos, Pavol & U., /Comenius
Description: We report on the measurement of the top quark electric charge using the jet charge tagging method on events containing a single lepton collected by the CDF II detector at Fermilab between February 2002 and February 2010 at the center-of-mass energy {radical}s = 1.96 TeV. There are three main components to this measurement: determining the charge of the W (using the charge of the lepton), pairing the W with the b-jet to ensure that they are from the same top decay branch and finally determining the charge of the b-jet using the Jet Charge algorithm. We found, on a sample of 5.6 fb{sup -1} of data, that the p-value under the standard model hypothesis is equal to 13.4%, while the p-value under the exotic model hypothesis is equal to 0.014%. Using the a priori criteria generally accepted by the CDF collaboration, we can say that the result is consistent with the standard model, while we exclude an exotic quark hypothesis with 95% confidence. Using the Bayesian approach, we obtain for the Bayes factor (2ln(BF)) a value of 19.6, that favors very strongly the SM hypothesis over the XM one. The presented method has the highest sensitivity to the top quark ...
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Search for the Higgs boson in the ZH->nunubb channel: Development of a b-tagging method based on soft muons

Search for the Higgs boson in the ZH->nunubb channel: Development of a b-tagging method based on soft muons

Date: October 1, 2010
Creator: Jamin, David & /Marseille, CPPM
Description: In the Standard Model of particle physics, the Higgs boson generates elementary particle masses. Current theoretical and experimental constraints lead to a Higgs boson mass between 114.4 and 158 GeV with 95% confidence level. Moreover, Tevatron has recently excluded the mass ranges between 100 and 109 GeV, 158 and 175 GeV with 95% confidence level. These results gives a clear indication to search for a Higgs boson at low mass. The D0 detector is located near Chicago, at the Tevatron, a proton-antiproton collider with an energy in the center of mass of 1.96 TeV. The topic of this thesis is the search for a Higgs boson in association with a Z boson. This channel is sensitive to low mass Higgs boson (<135 GeV) which has a branching ratio H {yields} bb varies between 50% and 90% in this mass range. The decay channel ZH {yields} {nu}{bar {nu}}b{bar b} studied has in the final state 2 heavy-flavor jets and some missing transverse energy due to escaping neutrinos. The heavy-flavor jets identification ('b-tagging') is done with a new algorithm (SLTNN) developped specifically for semi-leptonic decay of b quarks. The Higgs boson search analysis was performed with 3 fb{sup -1} of data. The ...
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A Dependence Study of $\Xi^{*0}$ and $\bar{\Xi}^{*0}$ in 250 GeV/c $\pi^-$. $K^-$ -nucleon Interactions

A Dependence Study of $\Xi^{*0}$ and $\bar{\Xi}^{*0}$ in 250 GeV/c $\pi^-$. $K^-$ -nucleon Interactions

Date: April 1, 2005
Creator: Seixas de Rezende, Fabio Antonio & /Rio de Janeiro, CBPF
Description: A direct measurement of the mass number (A) dependence of the production of the hyperon {Xi}*{sup 0} and its opposite {bar {Xi}}*{sup 0} in {pi}{sup -}, K{sup -} beam-nucleon interactions at 250 GeV/c is reported. The data derive from the experiment E769 at Fermilab. The results were obtained for different targets: Be, Al, Cu and W. It was observed the data are found to be well described by the parametrization {sigma}{sub A} = {sigma}{sub 0}A{sup {alpha}}, {alpha} being calculated for different beams. The results obtained are compared with those results of E769 experiment. The results shown here are preliminary.
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A brief introduction on training and public information of building energy codes in the U.S.

A brief introduction on training and public information of building energy codes in the U.S.

Date: December 1, 2010
Creator: Shui, Bin
Description: This report is associated with the project of Implementation of Building Energy Codes in China (55793). The report aims to give Chinese audience a brief introduction on training and public information activities of building energy codes in the U.S. The report contains four sections: Section One is about the development history and implementation of building energy codes in the U.S. Section Two is about the organizations of training and public information activities, mainly focused on ASHRAE, ICC, federal and state government. Policy implication, which is Section Three, addresses the role of federal government and on-line training and public information activities in promoting training and public information (the current China training system lacks strong support of central government and on-line training activities). Conclusions are made in Section Four. This report will be uploaded to an upcoming Chinese website which is devoted to provide first-time free on-line training and public information of building energy codes in China.
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Amplitude Analysis of the Decay $D_s^+ \to \pi^+ \pi^- \pi^+$ in the Experiment E831/FOCUS

Amplitude Analysis of the Decay $D_s^+ \to \pi^+ \pi^- \pi^+$ in the Experiment E831/FOCUS

Date: January 1, 2005
Creator: Schilithz, Anderson Correa; /Rio de Janeiro, CBPF & ,
Description: We present in this thesis the Dalitz Plot analysis of the D{sub s}{sup +} {yields} {pi}{sup +}{pi}{sup -}{pi}{sup +} decay, with the data of the E831/FOCUS, that took data in 1996 and 1997. The masses and widhts of f{sub 0}(980) and f{sub 0}(1370) are free parametres of the fit on Dalitz Plot, objectiving to study in detail these resonances. After this analysis we present the Spectator Model study on the S wave in this decay. For this study we used the formalism developed by M. Svec [2] for scattering. We present the comparison between the Isobar Model, frequently used in Dalitz Plot analysis, and this formalism.
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Study of the S-wave K(pi) --> Amplitude Using the Decay D+ --> K-pi+pi+

Study of the S-wave K(pi) --> Amplitude Using the Decay D+ --> K-pi+pi+

Date: February 1, 2007
Creator: Machado, Ana Amelia Bergamini & ,
Description: In this work the S-wave component of the K{pi} amplitude from decay of D{sup +} {yields} K{sup -}{pi}{sup +}{pi}{sup +} it is directly measured. The data come from the Fermilab E831/FOCUS experiment. The amplitude measurement is made using the partial wave analysis without any preliminary assumption about the nature of the S-wave component of the K{pi} system. The phase and magnitude of the S-wave amplitude are generic functions to be determined directly through the Dalitz plot fit. For the sake of comparison, our results the same decay is analyzed using the isobar model, which is the standard way to analyze the Dalitz plot. The data fit obtained with the partial wave analysis is better than the data fit from the isobar model. The phase variation with respect to the invariant mass K{pi} is compared with the measurement of the phase {delta}{sub I=1/2}{sup 0} (m{sub K{pi}}) from K{pi} {yields} K{pi} scattering. The difference between both analysis is discussed considering: a difference in the composition of the isospin components I = 1/2 and I = 3/2 of the K{pi} system between D{sup +} decay and the K{pi} {yields} K{pi} scattering; and the final state interaction involving all particles from decay.
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Tests of the Hardware and Software for the Reconstruction of Trajectories in the Experiment MINERvA

Tests of the Hardware and Software for the Reconstruction of Trajectories in the Experiment MINERvA

Date: May 1, 2009
Creator: Palomino Gallo, Jose Luis & /Rio de Janeiro, CBPF
Description: MINERvA experiment has a highly segmented and high precision neutrino detector able to record events with high statistic (over 13 millions in a four year run). MINERvA uses FERMILAB NuMI beamline. The detector will allow a detailed study of neutrino-nucleon interactions. Moreover, the detector has a target with different materials allowing, for the first time, the study of nuclear effects in neutrino interactions. We present here the work done with the MINERvA reconstruction group that has resulted in: (a) development of new codes to be added to the RecPack package so it can be adapted to the MINERvA detector structure; (b) finding optimum values for two of the MegaTracker reconstruction package variables: PEcut = 4 (minimum number of photo electrons for a signal to be accepted) and Chi2Cut = 200 (maximum value of {chi}{sup 2} for a track to be accepted); (c) testing of the multi anode photomultiplier tubes used at MINERvA in order to determine the correlation between different channels and for checking the device's dark counts.
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Antiproton structure function in p-pbar diffractive interactions at sqrt(s) = 1.96 TeV

Antiproton structure function in p-pbar diffractive interactions at sqrt(s) = 1.96 TeV

Date: July 1, 2007
Creator: Malbouisson, Helena & U., /Rio de Janeiro State
Description: No abstract prepared.
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OECM MCCI Small-Scale Water Ingression and Crust Strength Tests (SSWICS) SSWICS-2 final data report, Rev. 0 February 12, 2003.

OECM MCCI Small-Scale Water Ingression and Crust Strength Tests (SSWICS) SSWICS-2 final data report, Rev. 0 February 12, 2003.

Date: May 23, 2011
Creator: Lomperski, S.; Farmer, M. T.; Kilsdonk, D. & Aeschlimann, B. (Nuclear Engineering Division)
Description: The Melt Attack and Coolability Experiments (MACE) program at Argonne National Laboratory addressed the issue of the ability of water to cool and thermally stabilize a molten core/concrete interaction (MCCI) when the reactants are flooded from above. These tests provided data regarding the nature of corium interactions with concrete, the heat transfer rates from the melt to the overlying water pool, and the role of noncondensable gases in the mixing processes that contribute to melt quenching. However, due to the integral nature of these tests, several questions regarding the crust freezing behavior could not be adequately resolved. These questions include: (1) To what extent does water ingression into the crust increase the melt quench rate above the conduction-limited rate and how is this affected by melt composition and system pressure and (2) What is the fracture strength of the corium crust when subjected to a thermal-mechanical load and how does it depend upon the melt composition? A series of separate-effects experiments are being conducted to address these issues. The first employs an apparatus designed to measure the quench rate of a pool of corium ({approx}{phi}30 cm; up to 20 cm deep). The main parameter to be varied in these quench ...
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