1,489 research outputs found

    Production of f0(1710)f_0(1710), f0(1500)f_0(1500), and f0(1370)f_0(1370) in J/ψJ/\psi hadronic decays

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    A coherent study of the production of f0if_0^i (i=1i=1, 2, 3 corresponding to f0(1710)f_0(1710), f0(1500)f_0(1500), and f0(1370)f_0(1370)) in J/ψ→Vf0→VPPJ/\psi\to V f_0 \to V PP is reported based on a previously proposed glueball and QQˉQ\bar{Q} nonet mixing scheme, and a factorization for the decay of J/ψ→Vf0iJ/\psi\to V f_0^i, where VV denotes the isoscalar vector mesons ϕ\phi and ω\omega, and PP denotes pseudoscalar mesons. The results show that the J/ψJ/\psi decays are very sensitive to the structure of those scalar mesons, and suggest a glueball in the 1.5−1.71.5-1.7 GeV region, in line with Lattice QCD. The presence of significant glueball mixings in the scalar wavefunctions produces peculiar patterns in the branching ratios for J/ψ→Vf0i→VPPJ/\psi\to V f_0^i\to VPP, which are in good agreement with the recently published experimental data from the BES collaboration.Comment: Version accepted by PRD; Numerical results in Tab IV and VI changed due to correction of an error in quoting an experimental datum; Conclusion is not change

    Multichannel calculation for Ds* vector states and the Ds(2632) resonance

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    We study bound states below threshold and resonances above threshold in the D0-K+ and Ds-eta systems, using a many-coupled-channel model for non-exotic meson-meson scattering applied to states with the quantum numbers of c-sbar quark-antiquark vector mesons. We fit the ground state at 2.112 GeV, whence the lowest resonances in D0-K+ come out at 2.61, 2.72, 3.03, and 3.08 GeV. The resonance at 2.61 GeV acquires a width of about 8 MeV, while its partial P-wave cross section is up to six times larger in Ds-eta than in D0-K+, provided a mechanism accounting for Okubo-Zweig-Iizuka--forbidden decays is included. The latter finding is in agreement with the observations of the SELEX collaboration with respect to the recently reported DsJ(2632) resonance. Therefore, we conclude that the DsJ(2632) is most probably the first recurrence excitation of the Ds*(2112) meson.Comment: 11 pages, 6 figures; v2: Significant improvements for threshold behavior, and for the hadronic widths by including additional two-meson channels. Misprints in formulas correcte

    Glueball enhancements in p(gamma,VV)p through vector meson dominance

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    Double vector meson photoproduction, p(gamma, G -> VV)p, mediated by a scalar glueball G is investigated. Using vector meson dominance (VMD) and Regge/pomeron phenomenology, a measureable glueball enhancement is predicted in the invariant VV = rho rho and omega omega mass spectra. The scalar glueball is assumed to be the lightest physical state on the daughter pomeron trajectory governing diffractive vector meson photoproduction. In addition to cross sections, calculations for hadronic and electromagnetic glueball decays, G -> V V' (V,V'= rho, omega, phi, gamma), and gamma_v V -> G transition form factors are presented based upon flavor universality, VMD and phenomenological couplings from phi photoproduction analyses. The predicted glueball decay widths are similar to an independent theoretical study. A novel signature for glueball detection is also discussed

    Intrinsic Low Temperature Paramagnetism in B-DNA

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    We present experimental study of magnetization in λ\lambda-DNA in conjunction with structural measurements. The results show the surprising interplay between the molecular structures and their magnetic property. In the B-DNA state, λ\lambda-DNA exhibits paramagnetic behaviour below 20 K that is non-linear in applied magnetic field whereas in the A-DNA state, remains diamagnetic down to 2 K. We propose orbital paramagnetism as the origin of the observed phenomena and discuss its relation to the existence of long range coherent transport in B-DNA at low temperature.Comment: 5 pages, 4 figures, submitted to Physical Review Letters October 200

    Consistent analysis of the reaction γp→pη′\gamma p \to p \eta^\prime and pp→ppη′pp \to pp\eta^\prime

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    The production of η′\eta' mesons in the reactions γp→pη′\gamma p\to p\eta' and pp→ppη′pp\to pp\eta' is described consistently within a relativistic meson exchange model of hadronic interactions. The photoproduction can be described quite well over the entire energy range of available data by considering an S11S_{11} and a P11P_{11} resonance, in addition to the tt-channel mesonic current. The observed angular distribution is due to the interference between the tt-channel and the nucleon resonance ss- and uu-channel contributions. Our analysis yields positions close to 1650 MeV and 1870 MeV for the S11S_{11} and P11P_{11} resonances, respectively. We argue that, at present, identifying these states with the known S11(1650)S_{11}(1650) resonance and the missing P11P_{11} resonance predicted at 1880 MeV, respectively, would be premature. It is found that the nucleonic current is relatively small and that the NNη′NN\eta^\prime coupling constant cannot be much larger than gNNη′=3g_{NN\eta^\prime}=3. As for the pp→ppη′p p \to p p \eta^\prime reaction, different current contributions are constrained by a combined analysis of this and the photoproduction reaction. Difficulties to simultaneously account for the 47-MeV and 144-MeV angular distributions measured by the COSY-11 and DISTO collaborations, respectively, are addressed.Comment: minor revision, scheduled to a appear in Phys. Rev. C 69 (May 2004), revtex, 17 pages, 10 figures, 3 table

    Black hole thermalization rate from brane anti-brane model

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    We develop the quasi-particle picture for Schwarzchild and far from extremal black holes. We show that the thermalization equations of the black hole is recovered from the model of branes and anti-branes. This can also be viewed as a field theory explanation of the relationship between area and entropy for these black holes. As a by product the annihilation rate of branes and anti-branes is computed.Comment: 11 pages, late

    Polarization Observables in γN→KKˉN\gamma N\to K\bar{K}N

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    We explore some of the rich structure of the polarization observables recently developed for processes like γN→ππN\gamma N\to\pi\pi N and γN→KKˉN\gamma N\to K \bar{K} N in the framework of a specific model for the latter process. Emphasis is placed on observables that may be accesible at existing facilities in the near future. The sensitivity of the observables to the details of the model indicate that they will be a very useful tool in differentiating between different models for reactions like these. In the framework of a model for γN→KKˉN\gamma N\to K \bar{K} N, we examine the sensitivity of the observables to coupling constants of the ϕ\phi, to the properties of the Λ(1405)\Lambda(1405), and to the existence of the Θ+\Theta^+.Comment: 21 pages, latex, 17 figures, 1 style file include

    Chiral Lagrangian Parameters for Scalar and Pseudoscalar Mesons

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    The results of a high-statistics study of scalar and pseudoscalar meson propagators in quenched lattice QCD are presented. For two values of lattice spacing, β=5.7\beta=5.7 (a≈.18a \approx .18 fm) and 5.9 (a≈.12a \approx .12 fm), we probe the light quark mass region using clover improved Wilson fermions with the MQA pole-shifting ansatz to treat the exceptional configuration problem. The quenched chiral loop parameters m0m_0 and αΦ\alpha_{\Phi} are determined from a study of the pseudoscalar hairpin correlator. From a global fit to the meson correlators, estimates are obtained for the relevant chiral Lagrangian parameters, including the Leutwyler parameters L5L_5 and L8L_8. Using the parameters obtained from the singlet and nonsinglet pseudoscalar correlators, the quenched chiral loop effect in the nonsinglet scalar meson correlator is studied. By removing this QCL effect from the lattice correlator, we obtain the mass and decay constant of the ground state scalar, isovector meson a0a_0.Comment: 36 pages, 12 figures, LaTe

    Omega Production in pp Collisions

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    A model-independent irreducible tensor formalism which has been developed earlier to analyze measurements of p⃗p⃗→ppπ∘\vec{p}\vec{p}\to pp \pi^\circ, is extended to present a theoretical discussion of p⃗p⃗→ppω\vec{p}\vec{p}\to pp \omega and the polarization of ω\omega in pp→ppω⃗pp\to pp \vec{\omega}. The recent measurement of unpolarized differential cross section for pp→ppωpp\to pp \omega is analyzed using this theoretical formalism.Comment: 5 pages (double column), no figures, uses revtex

    Electronic inhomogeneity in EuO: Possibility of magnetic polaron states

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    We have observed the spatial inhomogeneity of the electronic structure of a single-crystalline electron-doped EuO thin film with ferromagnetic ordering by employing infrared magneto-optical imaging with synchrotron radiation. The uniform paramagnetic electronic structure changes to a uniform ferromagnetic structure via an inhomogeneous state with decreasing temperature and increasing magnetic field slightly above the ordering temperature. One possibility of the origin of the inhomogeneity is the appearance of magnetic polaron states.Comment: 4 pages, 3 figure
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