Showing papers by "Ludovico Pontecorvo published in 2003"
TL;DR: In this paper, the KLOE detector was used to measure the ratio R = Γ ( K L → γγ )/ Γ(K L → π 0 π γ ε 0 ε ε π + π − following the reaction e + e − → φ → K L K S from a sample of ∼10 9 φ -mesons produced at DAΦNE, the Frascati φ-factory, and obtained R =(279±002 stat ±002 syst )×10
12 citations
01 Jan 2003
TL;DR: In this article, the authors measured the branching ratio of φ mesons with the KLOE detector using a sample of ∼5×10 7 φ decays and fit the two-pion mass spectrum to models to disentangle contributions from various sources.
Abstract: Abstract We have measured the branching ratio BR( φ → π 0 π 0 γ ) with the KLOE detector using a sample of ∼5×10 7 φ decays. φ mesons are produced at DA Φ NE, the Frascati φ -factory. We find BR( φ → π 0 π 0 γ )=(1.09±0.03 stat ±0.05 syst )×10 −4 . We fit the two-pion mass spectrum to models to disentangle contributions from various sources.
4 citations
01 Jan 2003
TL;DR: The KLOE experiment at the DA$\Phi$NE $\phi$-factory in Frascati aims to determine the cross section of the dominant contribution of the muon at energies below 1 GeV exploiting the radiative return from the π to the ρ and ρ mesons as mentioned in this paper.
Abstract: The measurement of hadronic cross sections at low centre-of-mass energies is currently attracting much interest because of the r\^o{}le these measurements play in the theoretical evaluation of the anomalous magnetic moment of the muon. The KLOE experiment at the DA$\Phi$NE $\phi$-factory in Frascati aims to determine the cross section of the dominant contribution $e^{+}e^{-} \to \pi^{+}\pi^{-}$ at energies below 1 GeV exploiting the radiative return from the $\phi$ to the $\rho$ and $\omega$ mesons. This method has systematic errors completely different from previous measurements and allows a cross check of existing data in this energy region. The method and results on both the differential cross section for $e^{+}e^{-} \to \pi^{+}\pi^{-}\gamma$ and the total cross section for $e^{+}e^{-} \to \pi^{+}\pi^{-}$ are presented.
1 citations
01 Feb 2003
TL;DR: The KLOE experiment has been collecting data since April 1999 at the DAΦNE e+-e− collider at a center of mass energy equal to the o-meson mass.
Abstract: The KLOE experiment has been collecting data since April 1999 at the DAΦNE e+-e− collider at a center of mass energy equal to the o-meson mass. A total amount of 5 × 107 o decays have been analyzed. Results concerning the measurement of the semileptonic branching ratio of the KS, the measurement of the ratio BR(KS → π+π−)BR(KS → π0π0) and the study of the radiative decays of the o involving η, η′, ƒ0(980) and a0(980) are presented.
01 Apr 2003
TL;DR: In this paper, a sample of 5.3 × 10 7 φ mesons, produced at the Frascati φ-factory DAΦNE, has been used by the KLOE Collaboration to study the φ radiative decays.
Abstract: A sample of 5.3 × 10 7 φ mesons, produced at the Frascati φ-factory DAΦNE, has been used by the KLOE Collaboration to study the φ radiative decays. The decays φ → ηπ 0 γ and φ → π o π o γ have been exploited to study the scalar mesons a o (980) and f o (980). Furthermore a new determination of the η − η′ mixing angle has been obtained from the measurement of the ratio of the decay rates of / gf → η ′ γ to φ → ηγ .