Molecular structure of highly-excited resonant states in 24^{24}Mg and the corresponding 8^8Be+16^{16}O and 12^{12}C+12^{12}C decays

Exotic $^8$Be and $^{12}$C decays from high-lying resonances in $^{24}$Mg are analyzed in terms of a cluster model. The calculated quantities agree well with the corresponding experimental data. It is found that the calculated decay widths are very sensitive to the angular momentum carried by the outgoing cluster. It is shown that this property makes cluster decay a powerful tool to determine the spin as well as the molecular structures of the resonances.Comment: 17 pages, no figur

Nuclear Magnetic Quadrupole Moments in Single Particle Approximation

A static magnetic quadrupole moment of a nucleus, induced by T- and P-odd nucleon-nucleon interaction, is investigated in the single-particle approximation. Models are considered allowing for analytical solution. The problem is also treated numerically in a Woods-Saxon potential with spin-orbit interaction. The stability of results is discussed.Comment: LATEX, 9 pages, 1 postscript figure available upon request from "[email protected]". BINP 94-4

Evaluation of the mean intensity of the P-odd mixing of nuclear compound states

A temperature version of the shell-optical-model approach for describing the low-energy compound-to-compound transitions induced by external single-particle fields is given. The approach is applied to evaluate the mean intensity of the P-odd mixing of nuclear compound states. Unified description for the mixing and electromagnetic transitions allows one to evaluate the mean intensity without the use of free parameters. The valence-mechanism contribution to the mentioned intensity is also evaluated. Calculation results are compared with the data deduced from cross sections of relevant neutron-induced reactions.Comment: LaTeX, 10 page

The galactic foreground angular spectra

Galactic synchrotron and free-free foregrounds angular spectra are analytically estimated with account for interstellar turbulence and radiating process physics. Unknown parameters of the spectra are obtained by fitting to observational data

The HADES Tracking System

The tracking system of the dielectron spectrometer HADES at GSI Darmstadt is formed out of 24 low-mass, trapezoidal multi-layer drift chambers providing in total about 30 square meter of active area. Low multiple scattering in the in total four planes of drift chambers before and after the magnetic field is ensured by using helium-based gas mixtures and aluminum cathode and field wires. First in-beam performance results are contrasted with expectations from simulations. Emphasis is placed on the energy loss information, exploring its relevance regarding track recognition.Comment: 6 pages, 4 figures, presented at the 10th Vienna Conference on Instrumentation, Vienna, February 2004, to be published in NIM A (special issue

Earliness and morphotypes of common wheat cultivars of Western and Eastern Siberia

The global and local climate changes determine the producing of highly-adaptive common (bread) wheat commercial cultivars of a new generation whose optimal earliness matches the climatic features of the territory where the cultivars are farmed. Principal component analysis involving our own and published data has been applied to investigate 98 commercial common wheat cultivars from Western and Eastern Siberia comparing their morphotypes; cultivar zoning time; length of the vegetation period; 1000-grain weight, and inheritance of spring growth habit. It demonstrated that the dominant Vrn gene polymorphism determining the spring growth habit of the Siberian cultivars was minimally polymorphic. In 75 % of the tested cultivars, the spring growth habit was controlled by digenic, namely dominant Vrn-A1 and Vrn-B1 genes. In 25 % of them (24 cultivars), spring growth habit is controlled by a single gene. In 19 and 5 of these cultivars spring growth habit is controlled by only one dominant gene, Vrn-B1 or Vrn-A1, respectively. In cv. Tulun 15, a trigenic control was identified. A conclusion about the optimality of the digenic control for the climatic conditions of both Western and Eastern Siberia has been confirmed. However, since none of the tested cultivars had the dominant Vrn-D1 gene typical of the regions of China and Central Asia bordering Siberia, it can be considered as an additional argument in favor of the European origin of Siberian common wheat cultivars. The revealed high frequency of the Vrn-B1c allele in the Western Siberian cultivars and the Vrn-B1a allele in the Eastern Siberian cultivars suggests their selectivity. The analysis also confirmed the dominance of red glume (ferrugineum, milturum) and awned spike (ferrugineum, erythrospermum) varieties in the Eastern Siberian cultivars, and white glume and awnedless spike (lutescens and albidum) ones in the Western Siberian cultivars. Small grain size cultivars are more typical of Eastern than Western Siberia. The retrospective analysis based on the cultivars’ zoning time included in the “State Register for Selection Achievements Admitted for Usage” brought us to the conclusion that the earliness/lateness of modern Siberian commercial cultivars was not regionally but rather zonally-associated (taiga, subtaiga, forest-steppe and steppe zones)

Low-energy (anti)neutrino physics with Borexino: Neutrinos from the primary proton-proton fusion process in the Sun

The Sun is fueled by a series of nuclear reactions that produce the energy that makes it shine. The primary reaction is the fusion of two protons into a deuteron, a positron and a neutrino. These neutrinos constitute the vast majority of neutrinos reaching Earth, providing us with key information about what goes on at the core of our star. Several experiments have now confirmed the observation of neutrino oscillations by detecting neutrinos from secondary nuclear processes in the Sun; this is the first direct spectral measurement of the neutrinos from the keystone proton-proton fusion. This observation is a crucial step towards the completion of the spectroscopy of pp-chain neutrinos, as well as further validation of the LMA-MSW model of neutrino oscillations.Comment: Proceedings from NOW (Neutrino Oscillation Workshop) 201

Solar neutrino with Borexino: results and perspectives

Borexino is a unique detector able to perform measurement of solar neutrinos fluxes in the energy region around 1 MeV or below due to its low level of radioactive background. It was constructed at the LNGS underground laboratory with a goal of solar $^{7}$Be neutrino flux measurement with 5\% precision. The goal has been successfully achieved marking the end of the first stage of the experiment. A number of other important measurements of solar neutrino fluxes have been performed during the first stage. Recently the collaboration conducted successful liquid scintillator repurification campaign aiming to reduce main contaminants in the sub-MeV energy range. With the new levels of radiopurity Borexino can improve existing and challenge a number of new measurements including: improvement of the results on the Solar and terrestrial neutrino fluxes measurements; measurement of pp and CNO solar neutrino fluxes; search for non-standard interactions of neutrino; study of the neutrino oscillations on the short baseline with an artificial neutrino source (search for sterile neutrino) in context of SOX project.Comment: 15 pages, 4 figure

Lifetime measurements of 214Po and 212Po with the CTF liquid scintillator detector at LNGS

We have studied the alpha decays of 214Po into 210Pb and of 212Po into 208Pb tagged by the coincidence with the preceding beta decays from 214Bi and 212Bi, respectively. The employed 222Rn, 232Th, and 220Rn sources were sealed inside quartz vials and inserted in the Counting Test Facility at the underground Gran Sasso National Laboratory in Italy. We find that the mean lifetime of 214Po is (236.00 +- 0.42(stat) +- 0.15(syst)) \mu s and that of 212Po is (425.1 +- 0.9(stat) +- 1.2(syst)) ns. Our results, obtained from data with signal-to-background ratio larger than 1000, reduce the overall uncertainties and are compatible with previous measurements.Comment: RevTex, 11 pages, 5 figures, 3 tables. This second version matches the one accepted for publication in EPJA: minor stylistic changes plus a discussion of calibration of TDC time scal

The Borexino detector at the Laboratori Nazionali del Gran Sasso

Borexino, a large volume detector for low energy neutrino spectroscopy, is currently running underground at the Laboratori Nazionali del Gran Sasso, Italy. The main goal of the experiment is the real-time measurement of sub MeV solar neutrinos, and particularly of the mono energetic (862 keV) Be7 electron capture neutrinos, via neutrino-electron scattering in an ultra-pure liquid scintillator. This paper is mostly devoted to the description of the detector structure, the photomultipliers, the electronics, and the trigger and calibration systems. The real performance of the detector, which always meets, and sometimes exceeds, design expectations, is also shown. Some important aspects of the Borexino project, i.e. the fluid handling plants, the purification techniques and the filling procedures, are not covered in this paper and are, or will be, published elsewhere (see Introduction and Bibliography).Comment: 37 pages, 43 figures, to be submitted to NI