28,249 research outputs found

    ξ(2230)\xi(2230) is likely to be a glueball

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    On the basis of the recent results of ξ(2230)→π+π−,ppˉ\xi(2230)\rightarrow \pi^+\pi^-, p\bar p and ξ(2230)→K+K−, KSKS\xi(2230)\rightarrow K^+K^-,~K_SK_S, measured by the BES Collaboration in J/ψJ/\psi radiative decays, combined with the PS185 experiment of ppˉ→ξ(2230)→KKˉp\bar p\rightarrow \xi(2230)\rightarrow K\bar K, we argue that because of its very narrow partial decay widths to ππ\pi\pi and KKˉK\bar K ( less than 1 MeV1~MeV ), its large production rate in J/ψJ/\psi radiative decays, and its flavor- symmetric couplings to ππ\pi\pi and KKˉK\bar K, the ξ(2230)\xi(2230) is very likely to be a JPC=(even)++J^{PC}=(even)^{++} glueball.Comment: 6 pages in Latex, talk presented at the CCAST Workshop on Tau-Charm Factory, Beijing, November 199

    Interplanetary shock waves associated with solar flares

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    The interaction of the earth's magnetic field with the solar wind is discussed with emphasis on the influence of solar flares. The geomagnetic storms are considerered to be the result of the arrival of shock wave generated by solar flares in interplanetary space. Basic processes in the solar atmosphere and interplanetary space, and hydromagnetic disturbances associated with the solar flares are discussed along with observational and theoretical problems of interplanetary shock waves. The origin of interplanetary shock waves is also discussed

    Search for C=+C=+ charmonium and bottomonium states in e+e−→γ+Xe^+e^-\to \gamma+ X at B factories

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    We study the production of C=+C=+ charmonium states XX in e+e−→γ+Xe^+e^-\to \gamma + X at B factories with X=ηc(nS)X=\eta_c(nS) (n=1,2,3), χcJ(mP)\chi_{cJ}(mP) (m=1,2), and 1D2(1D)^1D_2(1D). In the S and P wave case, contributions of tree-QED with one-loop QCD corrections are calculated within the framework of nonrelativistic QCD(NRQCD) and in the D-wave case only the tree-QED contribution are considered. We find that in most cases the QCD corrections are negative and moderate, in contrast to the case of double charmonium production e+e−→J/ψ+Xe^+e^-\to J/\psi + X, where QCD corrections are positive and large in most cases. We also find that the production cross sections of some of these states in e+e−→γ+Xe^+e^-\to \gamma + X are larger than that in e+e−→J/ψ+Xe^+e^-\to J/\psi + X by an order of magnitude even after the negative QCD corrections are included. So we argue that search for the X(3872), X(3940), Y(3940), and X(4160) in e+e−→γ+Xe^+e^-\to \gamma + X at B factories may be helpful to clarify the nature of these states. For completeness, the production of bottomonium states in e+e−e^+e^- annihilation is also discussed.Comment: 13pages, 4 figure

    Reply to Comment on "Chiral suppression of scalar glueball decay"

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    Reply to the comment of Chao, He, and Ma

    A correlative study of SSC's, interplanetary shocks, and solar activity

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    A total of 93 SSC's were examined during the four year period from 1968 to 1971 at and near the peak of the solar activity cycle. Of the 93 SSC's 81 could be associated with solar activity, such as solar flares and radio bursts of Type II and Type IV. The mean propagation speeds of these flare-associated events ranged from 400 to 1000 km/sec with an average speed of 600-700 km/sec. Disturbances associated with 48 of the SSC's have been studied in detail using the corresponding interplanetary (IP) magnetic field, and plasma data when they were available. It was found that 41 of the 48 disturbances corresponded to IP shock waves, and the remaining seven events were tangential discontinuities. Thirty percent of the IP shocks had thick structure (i.e. the magnetic field jump across the shock occurred over a distance much greater than 50 proton Larmor radii). Also given is a statistical study of the gross geometry of a typical or average shock surface based on multiple spacecraft sightings and their relative orientation with respect to the solar flare. It is suggested that a typical shock front propagating out from the sun at l AU has a radius of curvature on the order of l AU. Also given are some general properties of oblique IP flare-shocks

    Reverse and Forward Slow Shocks in the Solar Wind

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    Reverse and forward slow shocks in solar wind from Pioneer 6 space prob

    Multiquark Hadrons

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    A number of candidate multiquark hadrons, i.e., particle resonances with substructures that are more complex than the quark-antiquark mesons and three-quark baryons that are prescribed in the textbooks, have recently been observed. In this talk I present: some recent preliminary BESIII results on the near-threshold behavior of sigma(e+e- --> Lambda Lambda-bar) that may or may not be related to multiquark mesons in the light- and strange-quark sectors; results from Belle and LHCb on the electrically charged, charmoniumlike Z(4430)^+ --> pi^+ psi ' resonance that necessarily has a four-quark substructure; and the recent LHCb discovery of the P_c(4380) and P_c(4450) hidden-charm resonances seen as a complex structure in the J/psi p invariant mass distribution for Lambda_b --> K^-J/psi p decays and necessarily have a five-quark substructure and are, therefore, prominent candidates for pentaquark baryons.Comment: 12 pages, 9 figures, summary of a talk presented at the 12th Conference on Hypernuclear and Strange Particle Physics (HYP2015), September 7-12, 2015 Sendai, JAPAN. To appear in the JPS Conference proceeding
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