[en] We have measured the three form factors governing the decay D⁺→ bar K ^*0e⁺ν_e, observed in Fermilab photoproduction experiment E691, using the complete decay distribution of the data. The results are A₁(0)=0.46±0.05±0.05, A₂(0)=0.0±0.2±0.1, and V(0)=0.9±0.3±0.1 for the two axial-vector and the vector form factors, respectively. The bar K ^*0 mesons have a ratio of longitudinal to transverse polarization of 1.8_-0.4^+0.6±0.3. These results are significantly different from values predicted by a number of different models

[en] We have searched for the inclusive reaction D_s^±→e^±X using a tagged sample of 68 D_s^± produced in the reaction e⁺e^-→D_s^±D_s^*minus-plus at a center-of-mass energy of 4.14 GeV. The tagged sample consists of the decays D_s⁺→φπ⁺, D_s⁺→ bar K ^*0K⁺, and D_s⁺→ bar K ⁰K⁺. We determine B(D_s⁺→e⁺X)=0.05_-0.05^+0.05±0.02, which corresponds to a limit of B(D_s⁺→e⁺X)<0.20, at the 90% confidence level

[en] The scalar meson nonet arising from fluctuations around the quark condensate are shown to have widths suppressed by a factor (1-g²f_π²/m_ρ²)³ relative to the σ-model values, when the effects of vector and axial vector mesons are included as given by the gauged chiral model. In particular we find Γ(δ → ηπ) = 27 MeV and Γ(κ → Κπ) = 330 MeV in more or less agreement with observations. (orig.)

[en] The production of b quarks in p bar p collisions is studied in the Collider Detector at Fermilab (CDF), using the B meson decay channels B⁺ → J/ψK⁺ and B⁰ → J/ψK*⁰, with J/ψ → μ⁺μ^- and K*⁰ → K⁺π^-, and their charge conjugates. Measurements of the B meson and b quark cross-sections integrated above minimum transverse momentum values in the rapidity range |y| < 1 are described. The first fully differential B meson cross-section measurement, in the same rapidity range, is also reported. Comparison is made to the O(α_s³) theoretical calculations

[en] Results from current algebra and QCD spectral sum rules (QSSR) in different hadronic channels within τ or n (sum rule variable) and t_c (continuum threshold) stability criterions or (and) t_c-values fixed from FESR are combined to give improved estimates of the light (u, d, s) and heavy (c, b) quark masses. In particular, the weighted averages of the s and b quark mass values are (unavoidably) accurate: anti m_s(1 GeV) = 159.5±8.8 MeV and M_b(q²=M_b²) = 4.58±0.05 GeV. Pion (repectively kaon) PCAC violations of (5±0.5)% (respectively (36.5±7.5)%) are observed while the values of the quark condensate ratios are: < anti dd > / < anti uu > = 1-9 x 10^-3 and < anti ss > / < anti uu > = 0.6±0.1. These confirm and improve earlier QSSR estimates and provide an indirect support of the anti qq nature of the a₀(0.98) and K₀^* (1.35). Values of the 'current' running masses of the c, b quarks are presented. Attempts to give the values of the light quark 'perturbative constituent' masses are done. (orig.)

[en] Recent Dalitz-plot analysis of the Kππ decays of the charmed D mesons done by the Mark III Collaboration has left some questions open. Especially the Dalitz distribution of the D⁺ → K^-π⁺π⁺ channel has an unexpected non-uniform non-resonant contribution. We show here that this behaviour can be explained in the framework of the BSW model (Bauer-Stech-Wirbel), assuming that the D⁺ → K^-π⁺π⁺ decay is dominated by the two-body decays D⁺ → anti K^*(897)π⁺ and D⁺ → anti K₀^*(1350)π⁺. (orig.)

[en] Scalar O⁺⁺ mesons are treated making use of the quark-gluon mixing model. It is shown that a decuplet of scalar particles exists consisting of S*(975), ε(1400), S*'(1730), δ(980), and ψ(1350) resonances. The long and well known S*(975) resonance turns out to be almost a pure glueball. All available data on scalar meson decays are well fitted

[en] The scalar meson nonet arising from fluctuations around quark condensates is incorporated into the gauged chiral model. We find its widths are more or less correctly given by the minimal model which, however, must be modified to produce the correct g_ρππ coupling and the large A₁ → ρπ decay rate found in recent τ decay measurements. This suggests that the scalar meson resonances at 1 GeV may be the particles associated with dynamical symmetry breaking. (orig.)

[en] The U_L(N_f)xU_R(N_f) chiral symmetric version of the Nambu-Jona-Lasinio model is extended by the 't Hooft determinant and bosonized for an arbitrary number of flavours N_f. The resulting effective meson lagrangian is explicitly calculated to leading order in the derivatives for three flavours. The 't Hooft determinant induces flavour mixing of the mesons with diagonal flavour content (π⁰, η, η', and their scalar chiral partners δ⁰, S, ε) and pushes up the physical η'-mass. The η-η' mixing angle is found to be -31⁰. (orig.)

[en] The work is aimed at discussing lower multiplets of radial excited states of light vector and pseudoscalar mesons. The authors follow an earlier developed scheme of phenomenologic analysis of radial excitations of qq-bar-systems (with orbital moment L=0). The conclusion is made that an adequate interpretation of pseudoscalar resonances largerly depends on solution of a number of problems connected with the general establishment of mass spectrum and other properties of radial excitations of light mesons. Presently known J^PC=0^± isosinglet (I⁶=O⁺) resonances are presented. A share of decay of J/ψ meson to form the assigned meson; the ratio of cross sections of production of the given meson and η-meson in π^-p reaction; width of two-photon decay of the given meson are presented. No significant mixing of pseudoscalar glueball with radial excitations of qq-states is supposed. The comparison of results obtained with the experiment will permit to estimate the degree of necessity of including new (gluon or multiquark) degrees of freedom to describe the picture observed