32 research outputs found

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

    Full text link
    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

    Get PDF
    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

    Get PDF
    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

    Full text link
    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

    Full text link
    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.

    No full text
    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
    corecore