31 research outputs found

    Measurement of the leptonic decay widths of the phi-meson with the KLOE detector

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    The phi-meson leptonic widths, Gee and Gmm, are obtained, respectively, from the e+e- forward-backward asymmetry and the muon cross section around the phi-mass energy. We find Gee=1.32⊕0.05⊕0.03 kev and sqrt(GeeGmm)= 1.320⊕0.018⊕0.017 kev. These results, compatible with Gee=Gmm, provide a precise test of lepton universality. Combining the two results gives G_lept=1.320⊕0.023 kev.Comment: 10 pages and 8 figures to be submitted to Phys.Lett.

    Measurement of the branching ratio for the decay K±π±π0π0K^\pm \to \pi^\pm \pi^0 \pi^0 with the KLOE detector

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    A new measurement of the absolute branching ratio BR(K±π±π0π0K^\pm \to \pi^\pm \pi^0 \pi^0) with the KLOE detector at the DAΦ\PhiNE e+ee^+e^- collider is presented, based on a sample of 3.3×107\sim 3.3\times 10^7 charged kaons tagged events, produced in the reaction e+eϕK+Ke^+e^-\to\phi\to K^+K^-.The value BR(K±π±π0π0K^\pm \to \pi^\pm \pi^0 \pi^0) =(1.781±0.013stat±0.016syst)= (1.781\pm 0.013_{stat}\pm 0.016_{syst})% has been obtained.Comment: Contributed paper to EPS 2003 and LP 200

    The hadronic cross section measurement at KLOE

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    KLOE uses the radiative return to measure cross section σ(e+e-->π+π-γ) at the electron-positron collider DAΦNE. Divinding by a theoretical radiator function, we obtain the cross section σ(e+e-->π+π-γ) for the mass range 0.35π<0.95GeV2. We calculate the hadronic contribution to the muon anomaly for the given mass range: aμ=388.7+/-0.8stat+/-3.5syst+/-3.5t

    Upper limit on the eta -> pi+pi- branching ratio with the KLOE experiment

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    We have searched with the KLOE detector for the P and CP violating decay eta -> pi^+pi^- in a sample of 1.55 x 10^7 eta's from the decay phi -> eta gamma of phi mesons produced in e+e- annihilations at DAFNE. No signal is found. We obtain the upper limit BR(eta -> pi^+pi^-) < 1.3 x 10^-5 at 90% confidence level.Comment: 8 pages, 3 figure

    Measurement of σ(e+eπ+πγ)\sigma(e^+e^-\to \pi^+ \pi^- \gamma) and extraction of σ(e+eπ+π)\sigma(e^+e^-\to \pi^+\pi^-) below 1 {\rm GeV} with the KLOE detector

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    We have measured the cross section σ(e+eπ+πγ)\sigma(e^+e^-\to \pi^+\pi^- \gamma) at an energy W=mϕ=1.02W=m_\phi=1.02 GeV with the KLOE detector at the electron-positron collider DAΦ\PhiNE. From the dependence of the cross section on the invariant mass of the two-pion system, we extract σ(e+eπ+π)\sigma(e^+e^-\to \pi^+\pi^-) for the mass range 0.35<s<0.950.35<s<0.95 GeV2^2. From this result, we calculate the pion form factor and the hadronic contribution to the muon anomaly, aμa_\mu.Comment: 20 pages, 12 figure

    MEASUREMENT OF SIGMA(E+E- --> PI+ PI- GAMMA) AND EXTRACTION OF SIGMA(E+E- --> PI+ PI-) BELOW 1-GEV WITH THE KLOE DETECTOR.

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    We have measured the cross section sigma(e+e -> pi+ pi- gamma) at an energy W = m_phi=1.02 GeV with the KLOE detector at the electron-positron collider DAFNE. From the dependence of the cross section on the invariant mass of the two-pion system, we extract sigma(e+e- -> pi+pi-) for the mass range 0.35 < s < 0.95 GeV^2. From this result, we calculate the pion form factor and the hadronic contribution to the muon anomaly, a_mu

    Improving needle detection in 3D ultrasound using orthogonal-plane convolutional networks

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    Successful automated detection of short needles during an intervention is necessary to allow the physician identify and correct any misalignment of the needle and the target at early stages, which reduces needle passes and improves health outcomes. In this paper, we present a novel approach to detect needle voxels in 3D ultrasound volume with high precision using convolutional neural networks. Each voxel is classified from locally-extracted raw data of three orthogonal planes centered on it. We propose a bootstrap re-sampling approach to enhance the training in our highly imbalanced data. The proposed method successfully detects 17G and 22G needles with a single trained network, showing a robust generalized approach. Extensive ex-vivo evaluations on 3D ultrasound datasets of chicken breast show 25% increase in F1-score over the state-of-the-art feature-based method. Furthermore, very short needles inserted for only 5 mm in the volume are detected with tip localization errors of &lt;0.5 mm, indicating that the tip is always visible in the detected plane
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