научный журнал по физике Ядерная физика ISSN: 0044-0027

CASTEN R.F., MCCUTCHAN E.A., ZAMFIR N.V. — 2004 г.

Shape/phase transitions in low-energy nuclear spectra, the new critical point symmetries E(5) and X(5), and their empirical realization have recently been the subject of many experimental and theoretical investigations. With a set of polar coordinates, the precise location of the critical phase transition region and of X(5)-type nuclei can be mapped in the Interacting Boson Model symmetry triangle. An empirical mapping of the symmetry triangle for the N = 82—104 rare-earth nuclei is also obtained.

HOLMLUND E., KORTELAINEN M., KOSMAS T.S., SUHONEN J., TOIVANEN J. — 2004 г.

Low-energy structure of the dark-matter detector nuclei 71 Ga, 73Ge, and 127I has been studied by using the microscopic quasiparticle—phonon model. The resulting ground states have been used to calculate theoretical predictions for detection rates of the lightest supersymmetric particle (LSP) in experiments studying elastic scattering of a LSP from an atomic nucleus. The highest rate, approximately 0.27 yr _1kg _1, among all the adopted SUSY parameters and renormalization schemes was provided by 127I at the zero limit of the detector energy threshold.

ANISIMOV A. YU. — 2004 г.

We provide a detailed numerical study of the influence of thermal effects on the original picture of the Affleck—Dine baryogenesis. These effects are found to modify the results greatly in some cases. We estimate the baryon/entropy ratio and provide numerical results on the typical behavior of the charge as a function of the strength of the potential and other parameters.

DROZDOV V.A., EREMENKO D.O., FOTINA О.V., PLATONOV S. YU., YUMINOV O.A. — 2004 г.

Approach based on the statistical theory of nuclear reactions and Monte Carlo method is used for evaluations of excited nuclear system characteristics like probability of decay channel (light particle, 7-quanta emission or fission), energy, emission angle of decay products and time characteristics of deexcitation processes. This method permits the direct simulation of experimental situation, in particular, nuclear-lifetime measurements by the crystal blocking technique. Decay times of compound nuclei formed in the fusion reactions 12C + 28Si → 40Ca and 19F + 28Si → 47V are estimated.

MUSULMANBEKOV G. — 2004 г.

Multiparticle production in high energy proton—proton collisions has been analyzed in the framework of Strongly Correlated Quark Model of the hadron structure elaborated by the author. It is shown that inelasticity decreases at high energies and the violation of KNO scaling is a consequence of total cross section growth and increasing with collision energy masses of intermediate clusters.

MANJAVIDZE J., VORONYUK V.V. — 2004 г.

The generating functional for probabilities is derived for the scalar model of Yang—Mills fields in terms of functional integrations. The example of 2 → 2 scattering is shown and problems that arise are mentioned.

KUZMENKO D.S., SIMONOV YU. A. — 2004 г.

The structure of hadrons consisting of three static color sources in fundamental (baryons) or adjoint (three-gluon glueballs) representations is studied. The static potentials of glueballs as well as gluon field distributions in glueballs and baryons are calculated in the framework of field correlator method.

AKIMUNE H., FUJIWARA M., FUSHIMI K., HARA K., HARA K.Y., ICHIHARA K., KAWASE K., MATSUI K., NAKANISHI K., NAKAYAMA S., SHIOKAWA A., TANAKA M., UTSUNOMIYA H., YAMAGATA T., YOSOI M. — 2004 г.

Trinucleon molecular structures in 6He and 6Be were investigated by using the 6Li( 7Li, 7Be) 6He reaction at 455 MeV and 6Li( 3He, t) 6Be reaction at 450 MeV, respectively. Binary decay into t +1 from a broad state at E x = 18.0 ± 1.0 MeV in 6He and into 3He + 3Hefrom one at E x = 18.0 ± 1.2 MeV in 6Be, respectively, were observed by measuring trinucleon cluster decays in coincidence with reaction particles. The branching ratios for binary decay were estimated to be about 0.7 for 6He and 6Be. These large branching ratios show that a trinucleon cluster state exists as an isobaric partner around E x = 18 MeV in 6He and 6Be.

HONZÂTKO J., KHITROV V.A., PANTELEEV C., SUKHOVOJ A.M., TOMAND I. — 2004 г.

Main properties of the excited states of 118Sn manifesting themselves in cascade γ decay of its compound state are studied. As in heavier nuclei studied earlier, qualitative interpretation of the whole set of observed properties of the nucleus appears to be impossible without accounting for coexistence and interaction of quasiparticle and collective nuclear excitations and their considerable influence on the main parameters of the process under study.

JENKOVSZKY L.L., STRUMINSKY В.V. — 2004 г.

Within a geometrical model developed in earlier papers a change of regime, or a “knee,” is predicted in the multiplicity distrubutions at large multiplicities. The position and motion of this “knee” is related to geometrical and KNO scaling and their violation, in particular the rise of the ratio σ el/σ t as well as to the transition from shadowing to antishadowing, expected at the LHC energies.

CHERNYAVSKY M.M., NAVOTNY V. SH., OSOSKOV G.A., POLANSKI A., UZHINSKY V.V. — 2004 г.

Experimental data on sulphur and oxygen nuclei interactions with photoemulsion nuclei at the energies of 200 and 60 GeV/nucleon are analyzed with the help of a continuous wavelet transform. Irregularities in pseudorapidity distributions of narrow groups of the secondary shower particles in the mentioned interactions are observed at application of the second order derivative of Gaussian as a wavelet. The irregularities can be interpreted as an existence of the preference emission angles of groups of particles.

DREMIN I.M. — 2004 г.

Wavelets are widely used now for the analysis of local scales (or frequencies) important in physical events, biological objects, natural phenomena etc. They provide unique information about scales at different locations. In particular, they are used for analysis of patterns in the phase space of very high multiplicity events.

BORZOV I.N. — 2004 г.

An important effort has been developed in last decades to measure the masses and β-decay rates of very neutron-rich nuclei at Radioactive Ion Beam (RIB) facilities. However, major astrophysical applications involve a huge number of exotic species. Most of them cannot be synthesized in terrestrial laboratories and only theoretical predictions can fill the gap. We concentrate on the self-consistent predictions of the 3-decay rates needed for stellar r-process modeling and for performing the RIB experiments. The continuum QRPA approach based on the self-consistent ground state description in the framework of the density functional theory is briefly described. The model for the large-scale calculations of total β-decay half-lives accounts for the Gamow—Teller and first-forbidden transitions. Due to the shell configuration effect, the first-forbidden decays have a strong impact on the total half-lives of the r-process relevant nuclei at N = 126, Z = 60—70. The performance of existing global models for the nuclides near the r-process paths at N = 126 is critically analyzed and confronted with the recent RIB experiments in the region “east” of 208 Pb.

AKIMUNE H., FUJIMURA H., FUJITA H., FUJITA M., FUJITA Y., HARA K.Y., HARA К., HATANAKA K., ISHIKAWA T., ITOH M., KAMIYA J., KAWABATA T., NAKAMURA M., NORO) T., SAKAGUCHI H., SHIMBARA Y., TAKEDA H., TAMII A., TOYOKAWA H., UCHIDA M., WAKASA T., YASUDA Y., YOSHIDA H.P., YOSOI M. — 2004 г.

Weak-interaction responses of 11B were studied by measuring the 11B( 3He, t) and 11B(p, p') reactions. Obtained nuclear transition matrix elements B(GT), B(στ), and B(σ) were compared with the shell-model calculations. The shell-model calculations, which reasonably well explained the isovector parts B(GT) and Β(στ) if the quenching factors of 0.5—0.7 were taken into account, did not describe the isoscalar part B(σ).

CHATTOPADHYAY U., CORSETTI A., NATH R. — 2004 г.

A brief review is given of the recent developments in the analyses of supersymmetric dark matter. Chief among these is the very accurate determination of the amount of cold dark matter in the universe from analyses using WMAP data. The implications of this data for the mSUGRA parameter space are analyzed. It is shown that the data admits solutions on the hyperbolic branch of the radiative breaking of the electroweak symmetry. A part of the hyperbolic branch lies in the so-called inversion region where the LSP neutralino χ 0 1 becomes essentially a pure Higgsino and degenerate with the next-to-the-lightest neutralino χ 0 2 and the light chargino χ ± 1. Thus, some of the conventional signals for the observation of supersymmetry at colliders (e.g., the missing energy signals) do not operate in this region. On the other hand, the inversion region contains a high degree of degeneracy of χ 0 1, χ 0 2, χ ± 1 leading to coannihilations which allow for the satisfaction of the WMAP relic density constraints deep on the hyperbolic branch. Further, an analysis of the neutralino—proton cross sections in this region reveals that this region can still be accessible to dark matter experiments in the future. Constraints from g μ — 2 and from B 0 S → μ+μ - are discussed. Future prospects are also discussed.

EFIMOV G.L., TOIVONEN D.E., TOKAREV M.V. — 2004 г.

The general features of particle production in hadron—hadron and hadron—nucleus collisions at high energy and transverse momentum using the concept of z-scaling are reviewed. z-Presentation of experimental data on the inclusive cross sections obtained at ISR, SPS, and Tevatron is presented and its properties are discussed. It is argued that the properties reflect the fundamental symmetries such as self-similarity, locality, and fractality. z-Scaling is used to predict particle yields in hadron—hadron and hadron—nucleus collisions at RHIC and LHC energies. The violation of z-scaling is considered as a signature of new physics phenomena.

GUGLIELMI A. — 2004 г.

The θ 13 mixing angle measurements in the neutrino oscillation experiments at accelerators are presented with the perspectives for futures neutrino beam facilities. Particular emphasis is devoted to near term new neutrino beam options, such low energy beams, and off-axis technique.

АБОВ Ю.Г. — 2004 г.

2004

ДУБИНИНА В.В., ЕГОРЕНКОВА Н.П., КРОТКОВА В.И., ПОЖАРОВА Е.А., СМИРНИТСКИЙ В.А. — 2004 г.

Измерена азимутальная анизотропия испускания фрагментов и релятивистских частиц при взаимодействии ядер 56Fe с импульсом 2.5 A ГэВ/c с ядрами фотоэмульсии. Для полуцентральных взаимодействий с прицельным параметром в интервале 0.12 ≤ b/b max ≤ 0.70 наблюдается преимущественный вылет фрагментов с зарядами Z и релятивистских частиц в направлении, перпендикулярном плоскости ядерной реакции. Параметр азимутальной анизотропии Р 2 для Z =1, Z =2 и Z ≥ 3 равен соответственно —0.192 ± 0.057, —0.28 ± 0.07 и —0.39 ± 0.12. Испарительные b-частицы имеют изотропное азимутальное распределение.