Pro-active Meeting Assistants: Attention Please!

This paper gives an overview of pro-active meeting assistants, what they are and when they can be useful. We explain how to develop such assistants with respect to requirement definitions and elaborate on a set of Wizard of Oz experiments, aiming to find out in which form a meeting assistant should operate to be accepted by participants and whether the meeting effectiveness and efficiency can be improved by an assistant at all. This paper gives an overview of pro-active meeting assistants, what they are and when they can be useful. We explain how to develop such assistants with respect to requirement definitions and elaborate on a set of Wizard of Oz experiments, aiming to find out in which form a meeting assistant should operate to be accepted by participants and whether the meeting effectiveness and efficiency can be improved by an assistant at all

Charged kaon lifetime at KLOE

Preliminary result on the charged kaon lifetime, obtained by the KLOE experiment operating at DA$\Phi$NE, the Frascati $\phi$-factory, is presentedComment: 3 pages, 3 figures, to appear in the proceedings of 42nd Rencontres de Moriond on Electroweak Interactions and Unified Theories, La Thuile, Aosta Valley, Italy, 10-17 Mar 200

Determination of CP and CPT violation parameters in the neutral kaon system using the Bell-Steinberger relation and data from the KLOE experiment

We present an improved determination of the CP and CPT violation parameters Re(epsilon) and Im(delta) based on the unitarity condition (Bell-Steinberger relation) and on recent results from the KLOE experiment. We find Re(epsilon) = (159.6 \pm 1.3)10^-5 and Im(delta) = (0.4 \pm 2.1)10^-5, consistent with no CPT violation.Comment: Submitted to JHE

A direct search for the CP-violating decay Ks->3p^0 with the KLOE detector at DAFNE

We have searched for the decay Ks->3p^0 with the KLOE experiment at DAFNE using data from e^+ e^- collisions at a center of mass energy W= m(phi) for an integrated luminosity L=450 pb^-1. The search has been performed with a pure Ks beam obtained by tagging with Kl interactions in the calorimeter and detecting six photons. We find an upper limit for the branching ratio of 1.2x10^-7 at 90% C.L.Comment: 15 pages, 6 figures. To be submitted to Physics Letter

Measurements of the Absolute Branching Ratios for the Dominant KL Decays, the KL Lifetime, and Vus with the KLOE Detector

From a sample of about 10^9 Phi mesons produced at DAFNE, we have selected KL mesons tagged by observing KS->pi+pi- decays. We present results on the major KL branching ratios, including those of the semileptonic decays needed for the determination of Vus. These branching ratio measurements are fully inclusive with respect to final-state radiation. The KL lifetime has also been measured.Comment: Submitted to Phys. Lett.

Measurement of the pseudoscalar mixing angle and η′\eta^{\prime} gluonium content with KLOE detector

We have measured the ratio $R_{\phi}=BR(\phi \to \eta^{\prime} \gamma)/BR(\phi \to \eta \gamma)$ by looking for the radiative decays $\phi \to \eta^{\prime} \gamma$ and $\phi \to \eta \gamma$ in the final states $\pi^+\pi^-$ 7 $\gamma$'s and 7 $\gamma$'s respectively, in a sample of $\sim 1.3\cdot 10^{9}$ $\phi$ mesons produced at the Frascati $\phi$-factory. We obtain $R_{\phi}=(4.77\pm0.09_{stat}\pm0.19_{sys})\cdot 10^{-3}$ from which we derive $BR(\phi \to \eta^{\prime} \gamma)=(6.20\pm0.11_{stat}\pm0.25_{sys})\cdot 10^{-5}$. In the hypothesis of no gluonium content we extract the pseudoscalar mixing angle in the quark-flavor basis $\phi_P=(41.4\pm0.3_{stat}\pm0.7_{sys}\pm0.6_{th})^{\circ}$. Combining the value of $R_{\phi}$ with other constraints, we estimate the gluonium fractional content of $\eta^{\prime}$ meson as $Z^2 = 0.14\pm0.04$ and the mixing angle $\phi_P = (39.7\pm0.7)^{\circ}$.Comment: 13 pages, 8 figure

First observation of quantum interference in the process phi -> KS KL ->pi+pi-pi+pi-: a test of quantum mechanics and CPT symmetry

We present the first observation of quantum interference in the process phi -> KS KL ->pi+pi-pi+pi-. This analysis is based on data collected with the KLOE detector at the e^+e^- collider DAFNE in 2001--2002 for an integrated luminosity of about 380pb^-1. Fits to the distribution of Delta t, the difference between the two kaon decay times, allow tests of the validity of quantum mechanics and CPT symmetry. No deviations from the expectations of quantum mechanics and CPT symmetry have been observed. New or improved limits on various decoherence and CPT violation parameters have been obtainedComment: submitted to Physics Letter B one number changed old:gamma=(1.1+2.9-2.4)10^-21 GeV new:(1.3+2.8-2.4)10^-21GeV corrected typo

Dalitz plot analysis of e+ e- --> pi0 pi0 gamma events at SQRT(s) ~ M(phi) with the KLOE detector

We have studied the Dalitz plot of the e+ e- --> pi0 pi0 gamma events collected at SQRT(s) ~ M(phi) with the KLOE detector. In the dipion invariant mass (Mpp) region below 700 MeV, the process under study is dominated by the non-resonant process e+ e- --> omega pi0 with omega --> pi0 gamma whereas, for higher Mpp values, the radiative phi decay to the f0(980) is the dominant mechanism. Different theoretical models are used to fit the Dalitz plot, taking also into account a possible contribution of the sigma(600). For each model, we extract the f0(980) mass and its coupling to pipi, KKbar and to the phi.Comment: 21 pages, 15 figures, 5 tables, submitted to European Physics Journal

Chemostratigraphy of Neoproterozoic carbonates: implications for 'blind dating'

The delta C-13(carb) and Sr-87/Sr-86 secular variations in Neoproteozoic seawater have been used for the purpose of 'isotope stratigraphy' but there are a number of problems that can preclude its routine use. In particular, it cannot be used with confidence for 'blind dating'. The compilation of isotopic data on carbonate rocks reveals a high level of inconsistency between various carbon isotope age curves constructed for Neoproteozoic seawater, caused by a relatively high frequency of both global and local delta C-13(carb) fluctuations combined with few reliable age determinations. Further complication is caused by the unresolved problem as to whether two or four glaciations, and associated negative delta C-13(carb) excursions, can be reliably documented. Carbon isotope stratigraphy cannot be used alone for geological correlation and 'blind dating'. Strontium isotope stratigraphy is a more reliable and precise tool for stratigraphic correlations and indirect age determinations. Combining strontium and carbon isotope stratigraphy, several discrete ages within the 590-544 Myr interval, and two age-groups at 660-610 and 740-690 Myr can be resolved