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1
مصطلحات موضوعية: High Energy Physics::Phenomenology, High Energy Physics::Experiment
الوصف: The mass of the W boson, a mediator of the weak force between elementary particles, is tightly constrained by the symmetries of the standard model of particle physics. The Higgs boson was the last missing component of the model. After observation of the Higgs boson, a measurement of the W boson mass provides a stringent test of the model. We measure the W boson mass, MW, using data corresponding to 8.8 inverse femtobarns of integrated luminosity collected in proton-antiproton collisions at a 1.96 tera-electron volt center-of-mass energy with the CDF II detector at the Fermilab Tevatron collider. A sample of approximately 4 million W boson candidates is used to obtain MW ¼ 80;433:5 T 6:4stat T 6:9syst ¼ 80;433:5 T 9:4 MeV=c2, the precision of which exceeds that of all previous measurements combined (stat, statistical uncertainty; syst, systematic uncertainty; MeV, mega-electron volts; c, speed of light in a vacuum). This measurement is in significant tension with the standard model expectation. © 2022 American Association for the Advancement of Science. All rights reserved.
URL الوصول: https://explore.openaire.eu/search/publication?articleId=od______2127::e0b8194b9d722f497d2bca1737bc08a4
https://pergamos.lib.uoa.gr/uoa/dl/object/uoadl:3219144 -
2
مصطلحات موضوعية: High Energy Physics::Phenomenology, Physics::Accelerator Physics, High Energy Physics::Experiment, Nuclear Experiment
الوصف: At the Fermilab Tevatron proton-antiproton (pp¯) collider, high-mass electron-neutrino (eν) pairs are produced predominantly in the process pp¯→W(→eν)+X. The asymmetry of the electron and positron yield as a function of their pseudorapidity constrain the slope of the ratio of the u- to d-quark parton distributions versus the fraction of the proton momentum carried by the quarks. This paper reports on the measurement of the electron-charge asymmetry using the full data set recorded by the Collider Detector at Fermilab in 2001-2011 and corresponding to 9.1 fb-1 of integrated luminosity. The measurement significantly improves the precision of the Tevatron constraints on the parton-distribution functions of the proton. Numerical tables of the measurement are provided. © 2021 authors. Published by the American Physical Society.
URL الوصول: https://explore.openaire.eu/search/publication?articleId=od______2127::4e0c89dc8ea36c6b575b4b1575750ce4
https://pergamos.lib.uoa.gr/uoa/dl/object/uoadl:3071702 -
3
مصطلحات موضوعية: High Energy Physics::Experiment
الوصف: We report on a search for a spin-zero non-standard model particle in proton-antiproton collisions collected by the Collider Detector at Fermilab at a center-of-mass-energy of 1.96 TeV. This particle, the φ boson, is expected to decay into a bottom-antibottom quark pair and to be produced in association with at least one bottom quark. The data sample consists of events with three jets identified as initiated by bottom quarks and corresponds to 5.4 fb-1 of integrated luminosity. In each event, the invariant mass of the two most energetic jets is studied by looking for deviations from the multijet background, which is modeled using data. No evidence is found for such a particle. Exclusion upper limits ranging from 20 to 2 pb are set for the product of production cross sections times branching fraction for the hypothetical φ boson with mass between 100 and 300 GeV/c2. These are the most stringent constraints to date. © 2019 authors. Published by the American Physical Society.
URL الوصول: https://explore.openaire.eu/search/publication?articleId=od______2127::a8e2a358290e891122c986570a58c2e2
https://pergamos.lib.uoa.gr/uoa/dl/object/uoadl:3072057 -
4
مصطلحات موضوعية: High Energy Physics::Phenomenology, High Energy Physics::Experiment
الوصف: The CDF and D0 experiments at the Fermilab Tevatron have measured the asymmetry between yields of forward- and backward-produced top and antitop quarks based on their rapidity difference and the asymmetry between their decay leptons. These measurements use the full data sets collected in proton-antiproton collisions at a center-of-mass energy of root s = 1.96 TeV. We report the results of combinations of the inclusive asymmetries and their differential dependencies on relevant kinematic quantities. The combined inclusive asymmetry is A(FB)(t (t) over bar) = 0.128 +/- 0.025. The combined inclusive and differential asymmetries are consistent with recent standard model predictions.
URL الوصول: https://explore.openaire.eu/search/publication?articleId=od______2127::3fbbf7bc5e541e5dd8927ac333355424
https://pergamos.lib.uoa.gr/uoa/dl/object/uoadl:3178635 -
5
مصطلحات موضوعية: Astrophysics::High Energy Astrophysical Phenomena, High Energy Physics::Phenomenology, Physics::Accelerator Physics, High Energy Physics::Experiment
الوصف: This paper presents a study of the production of a single W boson in association with one or more jets in proton-antiproton collisions at s=1.96 TeV, using the entire data set collected in 2001-2011 by the Collider Detector at Fermilab at the Tevatron, which corresponds to an integrated luminosity of 9.0 fb-1. The W boson is identified through its leptonic decays into electron and muon. The production cross sections are measured for each leptonic decay mode and combined after testing that the ratio of the W(→μν)+jets cross section to the W(→eν)+jets cross section agrees with the hypothesis of e-μ lepton universality. The combination of measured cross sections, differential in the inclusive jet multiplicity (W+≥N jets with N=1, 2, 3, or 4) and in the transverse energy of the leading jet, are compared with theoretical predictions. © 2018 authors.
URL الوصول: https://explore.openaire.eu/search/publication?articleId=od______2127::e50ce1b9d4ee0d04146159eb9839c6ae
https://pergamos.lib.uoa.gr/uoa/dl/object/uoadl:3072127 -
6
مصطلحات موضوعية: High Energy Physics::Experiment, Nuclear Experiment
الوصف: A measurement of the inclusive production cross section of isolated prompt photons in proton-antiproton collisions at center-of-mass energy s=1.96 TeV is presented. The results are obtained using the full Run II data sample collected with the Collider Detector at the Fermilab Tevatron, which corresponds to an integrated luminosity of 9.5 fb-1. The cross section is measured as a function of photon transverse energy, ETγ, in the range 30
URL الوصول: https://explore.openaire.eu/search/publication?articleId=od______2127::d80f62975fa4f4417a1a277dc8c387f2
https://pergamos.lib.uoa.gr/uoa/dl/object/uoadl:3072346 -
7
مصطلحات موضوعية: High Energy Physics::Experiment, Nuclear Experiment
الوصف: A measurement of vector boson (V) production in conjunction with a D*(2010)(+) meson is presented. Using a data sample corresponding to 9.7 fb(-1) of proton-antiproton collisions at center-of-mass energy root s = 1.96 TeV produced by the Fermilab Tevatron, we reconstruct V + D*+ samples with the CDF II detector. The D*+ is fully reconstructed in the D*(2010)(+) -> D-0 (-> K-pi(+))pi(+) decay mode. This technique is sensitive to the associated production of vector boson plus charm or bottom mesons. We measure the ratio of production cross sections sigma(W + D*) = sigma(W) = [1.75 +/- 0.13(stat) +/- 0.09(stat)]% and sigma(Z + D*)/sigma(Z) = [1.5 +/- 0.4(stat) +/- 0.2(stat)]% and perform a differential measurement of d sigma(W + D*)/dp(T)(D*). Event properties are utilized to determine the fraction of V + D*(2010)(+) events originating from different production processes. The results are in agreement with the predictions obtained with the PYTHIA program, limiting possible contribution from non-standard-model physics processes.
URL الوصول: https://explore.openaire.eu/search/publication?articleId=od______2127::b0e47071b43d8308a769d01c9198a53c
https://pergamos.lib.uoa.gr/uoa/dl/object/uoadl:3169527 -
8
مصطلحات موضوعية: High Energy Physics::Phenomenology, High Energy Physics::Experiment
الوصف: A search for a Higgs boson with suppressed couplings to fermions, h(f), assumed to be the neutral, lower-mass partner of the Higgs boson discovered at the Large Hadron Collider, is reported. Such a Higgs boson could exist in extensions of the standard model with two Higgs doublets, and could be produced via p (p) over bar -> H(+/-)h(f) -> W*h(f)h(f) -> 4 gamma + X where H (+/-) is a charged Higgs boson. This analysis uses all events withat least three photons in the final state from proton-antiproton collisions at a center-of-mass energy of 1.96 TeV collected by the Collider Detector at Fermilab, corresponding to an integrated luminosity of 9.2 fb(-1). No evidence of a signal is observed in the data. Values of Higgs-boson masses between 10 and 100 GeV/c(2) are excluded at 95% Bayesian credibility.
URL الوصول: https://explore.openaire.eu/search/publication?articleId=od______2127::619545d048cdafa687c5d8285dfec6b1
https://pergamos.lib.uoa.gr/uoa/dl/object/uoadl:3170413 -
9Measurement of the B-c(+/-) production cross section in p(p)over-tilde collisions at root s=1.96 TeV
مصطلحات موضوعية: High Energy Physics::Experiment, Nuclear Experiment
الوصف: We describe a measurement of the ratio of the cross sections times branching fractions of the B-c(+) meson in the decay mode B-c(+) -> J/psi mu(+)nu to the B+ meson in the decay mode B+ -> J/psi K+ in proton-antiproton collisions at center-of-mass energy root s = 1.96 TeV. The measurement is based on the complete CDF Run II data set, which comes from an integrated luminosity of 8.7 fb(-1). The ratio of the production cross sections times branching fractions for B-c(+) and B+ mesons with momentum transverse to the beam greater than 6 GeV/c and rapidity magnitude smaller than 0.6 is 0.211 +/- 0.012(stat)(-0.020)(+0.021)(syst). Using the known B+ -> J/psi K+ branching fraction, the known B+ production cross section, and a selection of the predicted B-c(+) -> J/psi mu(+nu) branching fractions, the range for the total B-c(+) production cross section is estimated.
URL الوصول: https://explore.openaire.eu/search/publication?articleId=od______2127::c3ae1547af50063bcd5d4217c087c930
https://pergamos.lib.uoa.gr/uoa/dl/object/uoadl:3169438 -
10
مصطلحات موضوعية: High Energy Physics::Phenomenology, High Energy Physics::Experiment
الوصف: Combined constraints from the CDF and D0 Collaborations on models of the Higgs boson with exotic spin J and parity P are presented and compared with results obtained assuming the standard model value J(P) = 0(+). Both collaborations analyzed approximately 10 fb(-1) of proton-antiproton collisions with a center-of-mass energy of 1.96 TeV collected at the Fermilab Tevatron. Two models predicting exotic Higgs bosons with J(P) = 0(-) and J(P) = 2(+) are tested. The kinematic properties of exotic Higgs boson production in association with a vector boson differ from those predicted for the standard model Higgs boson. Upper limits at the 95% credibility level on the production rates of the exotic Higgs bosons, expressed as fractions of the standard model Higgs boson production rate, are set at 0.36 for both the J(P) = 0(-) hypothesis and the J(P) = 2(+) hypothesis. If the production rate times the branching ratio to a bottom-antibottom pair is the same as that predicted for the standard model Higgs boson, then the exotic bosons are excluded with significances of 5.0 standard deviations and 4.9 standard deviations for the J(P) = 0(-) and J(P) = 2(+) hypotheses, respectively.
URL الوصول: https://explore.openaire.eu/search/publication?articleId=od______2127::44d2776d44b0bd12680a91544dd7cf7a
https://pergamos.lib.uoa.gr/uoa/dl/object/uoadl:3165627