Can low-lying Roper states be explained as antidecuplet members?

It is shown that the anomalously low-lying Roper states cannot be assigned as pentaquarks with the scalar diquark - scalar diquark - antiquark structure as suggested by Jaffe and Wilczek.Comment: Will appear in Phys. Rev. Lett. as a comment on the paper by R. Jaffe and F. Wilczek, Phys. Rev. Lett., 91, 232003 (2003

Why the OZI rule is so strongly violated in J/Psi decays?

The new $f_0(1790)$ meson recently observed by BES collaboration in $J/\Psi$-decay, is seen only in the OZI-forbidden channel. It is shown that chiral symmetry restoration in excited hadrons implies a new selection rule of dynamical origin that forbids some of the OZI-favoured mechanisms of decays. Hence decays into channels that are suppressed by OZI can become dominant.Comment: 5 pages, 5 figures. The paper has been expanded. A new figure as well as implications of chiral symmetry for the search of missing a_0 mesons in charmonium decays have been added. To appear in Phys. Rev.

Optimization of a linear inductive MHD machine considering the longitudinal end effect

Optimization of linear inductive magnetohydrodynamic machine considering longitudinal end effec

Non-dipole angular anisotropy parameters of semi-filled shell atoms

We present the results of calculations of outer shell non-dipole angular anisotropy parameters for semi-filled shell atoms in the Hartree-Fock (HF) one-electron approximation and with account of inter-electron correlations in the frame of the Spin Polarized Random Phase Approximation with Exchange (SP RPAE). We demonstrate for the first time that this characteristic of photoionization process is essentially sensitive to the fact whether the photoelectron has the same or opposite spin orientation to that of the semi-filled shell.Comment: 15 pages, 8 figure

Large-scale magnetic fields, curvature fluctuations and the thermal history of the Universe

It is shown that gravitating magnetic fields affect the evolution of curvature perturbations in a way that is reminiscent of a pristine non-adiabatic pressure fluctuation. The gauge-invariant evolution of curvature perturbations is used to constrain the magnetic power spectrum. Depending on the essential features of the thermodynamic history of the Universe, the explicit derivation of the bound is modified. The theoretical uncertainty in the constraints on the magnetic energy spectrum is assessed by comparing the results obtained in the case of the conventional thermal history with the estimates stemming from less conventional (but phenomenologically allowed) post-inflationary evolutions.Comment: 21 pages, 6 included figure