Gross, intermediate and fine structure of nuclear giant resonances: Evidence for doorway states

We review the phenomenon of fine structure of nuclear giant resonances and its relation to different resonance decay mechanisms. Wavelet analysis of the experimental spectra provides quantitative information on the fine structure in terms of characteristic scales. A comparable analysis of resonance strength distributions from microscopic approaches incorporating one or several of the resonance decay mechanisms allows conclusions on the source of the fine structure. For the isoscalar giant quadrupole resonance (ISGQR), spreading through the first step of the doorway mechanism, i.e.\ coupling between one particle-one hole ($1p1h$) and two particle-two hole ($2p2h$) states is identified as the relevant mechanism. In heavy nuclei it is dominated by coupling to low-lying surface vibrations, while in lighter nuclei stochastic coupling becomes increasingly important. The fine structure observed for the isovector giant dipole resonance (IVGDR) arises mainly from the fragmentation of the $1p1h$ strength (Landau damping), although some indications for the relevance of the spreading width are also found.Comment: 15 pages, 16 figures. Submitted to Eur. Phys. J A, special issue "Giant, pygmy, pairing resonances and related topics

Checklist of longicorn beetles (Coleoptera, Cerambycidae) of Omsk Region (Russia)

An annotated check-list of the longicorn beetles of Omsk Region is given. The list based on literature data and collecting materials of authors. 41 species are new to the fauna of Omsk Region

Parameters of broadening of water molecule absorption lines by argon derived using different line profile models

The water vapor absorption spectrum was measured in the spectral region 6700–7650 cm–1 with argon as a buffer gas. The room-temperature spectrum was measured using a Bruker IFS 125-HR Fourier Transform Spectrometer with high signal-to-noise ratio, with a spectral resolution of 0.01 cm–1, at argon pressures from 0 to 0.9 atm. The H2O absorption spectral line parameters are derived by fitting two line shape profiles (Voigt and speed-dependent Voigt) to the experimental spectrum. It is shown that the use of speed-dependent Voigt profile provides the best agreement with experimental data

Modification of the experimental setup of the FTIR spectrometer and thirty-meter optical cell for measurements of weak selective and nonselective absorptions

The improvement of the experimental setup based on a Fourier spectrometer Bruker IFS-125 and a 30-meter multipass optical cell is described. The improvement includes the cell equipment with a system of automated adjustment of the number of beam passes without cell depressurization and ensures the cell work at high temperatures

Electric dipole response in ¹²⁰Sn

In high-resolution (p̅,p̅) experiments under 0° the complete B(E1) strength distribution can be studied in stable nuclei. At the Research Center of Nuclear Physics in Osaka, Japan, the cross sections and observables for the polarization transfer of E1 and M1 excitations in ¹²⁰Sn were measured for scattering angles Θ = 0° − 4° in an excitation energy range of 5 - 25 MeV. From the present measurement the complete B(E1) strength distribution and the branching ratios of the PDR to the ground state can be extracted. The experimental setup, the principle of backgound subtraction and first results on the E1 strength are presented