305 research outputs found

    Discovery of Calcium, Indium, Tin, and Platinum Isotopes

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    Currently, twenty-four calcium, thirty-eight indium, thirty-eight tin and thirty-nine platinum isotopes have been observed and the discovery of these isotopes is discussed here. For each isotope a brief synopsis of the first refereed publication, including the production and identification method, is presented.Comment: to be published in At. Data Nuclear Data Tables, This updated paper combines manuscripts: 1004.4934 (Calcium), 1004.5266 (Indium), 1003.5127 (Tin), and 1006.4033 (Platinum

    Final-State Phases in Charmed Meson Two-Body Nonleptonic Decays

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    Observed decay rates indicate large phase differences among the amplitudes for the charge states in DKˉπD \to \bar K \pi and DKˉπD \to \bar K^* \pi but relatively real amplitudes in the charge states for DKˉρD \to \bar K \rho. This feature is traced using an SU(3) flavor analysis to a sign flip in the contribution of one of the amplitudes contributing to the latter processes in comparison with its contribution to the other two sets. This amplitude may be regarded as an effect of rescattering and is found to be of magnitude comparable to others contributing to charmed particle two-body nonleptonic decays.Comment: 19 pages, latex, 4 figures, to be submitted to Phys. Rev.

    Towards resolution of the enigmas of P-wave meson spectroscopy

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    The mass spectrum of P-wave mesons is considered in a nonrelativistic constituent quark model. The results show the common mass degeneracy of the isovector and isodoublet states of the scalar and tensor meson nonets, and do not exclude the possibility of a similar degeneracy of the same states of the axial-vector and pseudovector nonets. Current experimental hadronic and \tau -decay data suggest, however, a different scenario leading to the a_1 meson mass \simeq 1190 MeV and the K_{1A}-K_{1B} mixing angle \simeq (37\pm 3)^o. Possible s\bar{s} states of the four nonets are also discussed.Comment: 22 pages, LaTe

    Partial Wave Analysis of J/ψγ(K+Kπ+π)J/\psi \to \gamma (K^+K^-\pi^+\pi^-)

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    BES data on J/ψγ(K+Kπ+π)J/\psi \to \gamma (K^+K^-\pi^+\pi^-) are presented. The KKˉK^*\bar K^* contribution peaks strongly near threshold. It is fitted with a broad 0+0^{-+} resonance with mass M=1800±100M = 1800 \pm 100 MeV, width Γ=500±200\Gamma = 500 \pm 200 MeV. A broad 2++2^{++} resonance peaking at 2020 MeV is also required with width 500\sim 500 MeV. There is further evidence for a 2+2^{-+} component peaking at 2.55 GeV. The non-KKˉK^*\bar K^* contribution is close to phase space; it peaks at 2.6 GeV and is very different from KKˉK^{*}\bar{K^{*}}.Comment: 15 pages, 6 figures, 1 table, Submitted to PL

    Anti-Search for the Glueball Candidate f_J(2220) in Two-Photon Interactions

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    Using 13.3 fb^{-1} of e^+e^- data recorded with the CLEO II and CLEO II.V detector configurations at CESR, we have searched for f_J(2220) decays to K^0_{S} K^0_{S} in untagged two-photon interactions. We report an upper limit on the product of the two-photon partial width and the branching fraction, Gamma_gamma gamma cdot B (f_J(2220) to K^0_{S} K^0_{S}) of less than 1.1 eV at the 95% C.L: systematic uncertainties are included. This dataset is four times larger than that used in the previous CLEO publication.Comment: 10 pages postscript, also available through http://w4.lns.cornell.edu/public/CLNS, Submitted to PRD (R

    Measurement of the Charged Multiplicities in b, c and Light Quark Events from Z0 Decays

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    Average charged multiplicities have been measured separately in bb, cc and light quark (u,d,su,d,s) events from Z0Z^0 decays measured in the SLD experiment. Impact parameters of charged tracks were used to select enriched samples of bb and light quark events, and reconstructed charmed mesons were used to select cc quark events. We measured the charged multiplicities: nˉuds=20.21±0.10(stat.)±0.22(syst.)\bar{n}_{uds} = 20.21 \pm 0.10 (\rm{stat.})\pm 0.22(\rm{syst.}), nˉc=21.28±0.46(stat.)0.36+0.41(syst.)\bar{n}_{c} = 21.28 \pm 0.46(\rm{stat.}) ^{+0.41}_{-0.36}(\rm{syst.}) nˉb=23.14±0.10(stat.)0.37+0.38(syst.)\bar{n}_{b} = 23.14 \pm 0.10(\rm{stat.}) ^{+0.38}_{-0.37}(\rm{syst.}), from which we derived the differences between the total average charged multiplicities of cc or bb quark events and light quark events: Δnˉc=1.07±0.47(stat.)0.30+0.36(syst.)\Delta \bar{n}_c = 1.07 \pm 0.47(\rm{stat.})^{+0.36}_{-0.30}(\rm{syst.}) and Δnˉb=2.93±0.14(stat.)0.29+0.30(syst.)\Delta \bar{n}_b = 2.93 \pm 0.14(\rm{stat.})^{+0.30}_{-0.29}(\rm{syst.}). We compared these measurements with those at lower center-of-mass energies and with perturbative QCD predictions. These combined results are in agreement with the QCD expectations and disfavor the hypothesis of flavor-independent fragmentation.Comment: 19 pages LaTex, 4 EPS figures, to appear in Physics Letters

    Time-integrated luminosity recorded by the BABAR detector at the PEP-II e+e- collider

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    This article is the Preprint version of the final published artcile which can be accessed at the link below.We describe a measurement of the time-integrated luminosity of the data collected by the BABAR experiment at the PEP-II asymmetric-energy e+e- collider at the ϒ(4S), ϒ(3S), and ϒ(2S) resonances and in a continuum region below each resonance. We measure the time-integrated luminosity by counting e+e-→e+e- and (for the ϒ(4S) only) e+e-→μ+μ- candidate events, allowing additional photons in the final state. We use data-corrected simulation to determine the cross-sections and reconstruction efficiencies for these processes, as well as the major backgrounds. Due to the large cross-sections of e+e-→e+e- and e+e-→μ+μ-, the statistical uncertainties of the measurement are substantially smaller than the systematic uncertainties. The dominant systematic uncertainties are due to observed differences between data and simulation, as well as uncertainties on the cross-sections. For data collected on the ϒ(3S) and ϒ(2S) resonances, an additional uncertainty arises due to ϒ→e+e-X background. For data collected off the ϒ resonances, we estimate an additional uncertainty due to time dependent efficiency variations, which can affect the short off-resonance runs. The relative uncertainties on the luminosities of the on-resonance (off-resonance) samples are 0.43% (0.43%) for the ϒ(4S), 0.58% (0.72%) for the ϒ(3S), and 0.68% (0.88%) for the ϒ(2S).This work is supported by the US Department of Energy and National Science Foundation, the Natural Sciences and Engineering Research Council (Canada), the Commissariat à l’Energie Atomique and Institut National de Physique Nucléaire et de Physiquedes Particules (France), the Bundesministerium für Bildung und Forschung and Deutsche Forschungsgemeinschaft (Germany), the Istituto Nazionale di Fisica Nucleare (Italy), the Foundation for Fundamental Research on Matter (The Netherlands), the Research Council of Norway, the Ministry of Education and Science of the Russian Federation, Ministerio de Ciencia e Innovación (Spain), and the Science and Technology Facilities Council (United Kingdom). Individuals have received support from the Marie-Curie IEF program (European Union) and the A.P. Sloan Foundation (USA)

    Meson-meson interactions in a nonperturbative chiral approach

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    A non-perturbative method which combines constraints from chiral symmetry breaking and coupled channel unitarity is used to describe the meson-meson interaction up to about 1.2 GeV. The approach uses the O(p^2) and O(p^4) chiral Lagrangians. The seven free parameters of the O(p^4) Lagrangian are fitted to the data. The results are in good agreement with a vast amount of experimental analyses. The amplitudes develop poles in the complex plane corresponding to the f0, a0, rho, K*, phi, sigma and kappa resonances; the latter two, very broad. The total and partial decay widths of the resonances are also well reproduced. Further extensions and applications of this chiral non-perturbative scheme are also discussed

    Exotic ρ±ρ0\rho^\pm\rho^0 state photoproduction

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    It is shown that the list of unusual mesons planned for a careful study in photoproduction can be extended by the exotic states X±(1600)X^\pm(1600) with IG(JPC)=2+(2++)I^G(J ^{PC})=2^+(2^{++}) which should be looked for in the ρ±ρ0\rho^\pm\rho^0 decay channels in the reactions γNρ±ρ0N\gamma N\to\rho^\pm\rho^0N and γNρ±ρ0Δ\gamma N\to\rho^\pm \rho^0\Delta. The full classification of the ρ±ρ0\rho^\pm\rho^0 states by their quantum numbers is presented. A simple model for the spin structure of the γpf2(1270)p \gamma p\to f_2(1270)p, γpa20(1320)p\gamma p\to a^0_2(1320)p, and γNX±(N,Δ)\gamma N\to X^\pm (N, \Delta) reaction amplitudes is formulated and the tentative estimates of the corresponding cross sections at the incident photon energy Eγ6E_\gamma\approx 6 GeV are obtained: σ(γpf2(1270)p)0.12\sigma(\gamma p\to f_2(1270)p)\approx0.12 μ\mub, σ(γpa20(1320)p)0.25 \sigma(\gamma p\to a^0_2(1320)p)\approx0.25 μ\mub, σ(γNX±Nρ±ρ0N)0.018\sigma(\gamma N\to X^\pm N\to\rho^\pm\rho^0N)\approx0.018 μ\mub, and σ(γpXΔ++ρρ0Δ++)0.031\sigma(\gamma p\to X^-\Delta^{++ }\to\rho^-\rho^0\Delta^{++})\approx0.031 μ\mub. The problem of the X±X^\pm signal extraction from the natural background due to the other π±π0π+π\pi^\pm\pi^0 \pi^+\pi^- production channels is discussed. In particular the estimates are presented for the γph1(1170)π+n\gamma p\to h_1(1170)\pi^+n, γpρ+nπ+π0π+πn\gamma p\to\rho'^{+}n\to \pi^+\pi^0\pi^+\pi^-n, and γpωρ0p\gamma p\to\omega\rho^0p reaction cross sections. Our main conclusion is that the search for the exotic X±(2+(2++))X^\pm(2^+(2^{++})) states is quite feasible at JEFLAB facility. The expected yield of the γNX±Nρ±ρ0N\gamma N\to X^\pm N\to\rho^\pm\rho^0N events in a 30-day run at the 100% detection efficiency approximates 2.8×1062.8\times10^6 events.Comment: 19 pages, revtex, 1 figure in postscipt, some comments and references added, a few minor typos corrected, to be published in Phys. Rev.
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