Hadronic and radiative three-body decays of J/psi involving the scalars f0(1370), f0(1500) and f0(1710)

We study the role of the scalar resonances f0(1370), f0(1500) and f0(1710) in the strong and radiative three-body decays of J/psi with J/psi to V + P P (gamma gamma) and J/psi to gamma + P P (V V), where P (V) denotes a pseudoscalar (vector) meson. We assume that the scalars result from a glueball-quarkonium mixing scheme while the dynamics of the transition process is described in an effective chiral Lagrangian approach. Present data on J/psi to V + P P are well reproduced, predictions for the radiative processes serve as further tests of this scenario.Comment: 15 page

New features of collective motion of intrinsic degrees of freedom. Toward a possible way to classify the intrinsic states

Three exactly solvable Hamiltonians of complex structure are studied in the framework of a semi-classical approach. The quantized trajectories for intrinsic coordinates correspond to energies which may be classified in collective bands. For two of the chosen Hamiltonians the symmetry SU2xSU2 is the appropriate one to classify the eigenvalues in the laboratory frame. Connections of results presented here with the molecular spectrum and Moszkowski model are pointed out. The present approach suggests that the intrinsic states, which in standard formalisms are heading rotational bands, are forming themselves "rotational" bands, the rotations being performed in a fictious boson space.Comment: 33 pages, 9 figure

Description of double beta decay within continuum-QRPA

A method to calculate the nuclear double beta decay ($2\nu\beta\beta$- and $0\nu\beta\beta$-) amplitudes within the continuum random phase approximation (cQRPA) is formulated. Calculations of the $\beta\beta$ transition amplitudes within the cQRPA are performed for ^{76}Ge, ^{100}Mo and ^{130}Te. A rather simple nuclear Hamiltonian consisting of phenomenological mean field and zero-range residual particle-hole and particle-particle interaction is used. The calculated M^{2\nu} are almost not affected when the single-particle continuum is taken into account. At the same time, a regular suppression of the $0\nu\beta\beta$-amplitude is found that can be associated with additional ground state correlations due to collective states in the continuum. It is expected that future inclusion of the nucleon pairing in the single-particle continuum will somewhat compensate the suppression.Comment: 20 pages, 1 figure, published versio

In-medium dependence and Coulomb effects of the pion production in heavy ion collisions

The properties of the high energy pions observed in heavy ion collisions, in particular in the system Au on Au at 1 GeV/nucleon are investigated. The reaction dynamics is described within the Quantum Molecular Dynamics (QMD) approach. It is shown that high energy pions freeze out early and originate from the hot, compressed matter. $N^*$--resonances are found to give an important contribution toward the high energy tail of the pion. Further the role of in-medium effects in the description of charged pion yields and spectra is investigated using a microscopic potential derived from the Brueckner G-matrix which is obtained with the Reid soft-core potential. It is seen that the high energy part of the spectra is relatively more suppressed due to in-medium effects as compared to the low energy part. A comparision to experiments further demonstrates that the present calculations describe reasonably well the neutral (TAPS) and charged (FOPI) pion spectra. The observed energy dependence of the $\pi^-/\pi^+$ ratio, i.e. deviations from the isobar model prediction, is due to Coulomb effects and again indicate that high energy pions probe the hot and dense phase of the reaction. These findings are confirmed independently by a simple phase space analysis.Comment: 28 pages Latex, prepared with elsevier-style, 13 PS-figure