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AbstractAbstract

[en] This paper reports on simple coherent state expansions completed by assumptions about correlations which allows the author to derive, in a mathematically rigorous way, a variety of multiplicity, transverse energy (momentum) and angular distributions. The usefulness at least of some of them is manifested by the data obtained recently in 1-1, 1-h, h-h and h-nucleus collisions. Several problems concerning the multiplicity scaling are shortly mentioned too

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Dremin, I.; Gulamov, K; 820 p; ISBN 997-1-50507-X; ; 1988; p. 187-194; World Scientific Pub. Co; Teaneck, NJ (United States); 18. international symposium on multiparticle dynamics; Tashkent (USSR); 8-12 Sep 1987; CONF-8709152--; World Scientific Pub. Co., 687 Hartwell Street, Teaneck, NJ 07666 (United States)

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Imbo, T.D.

Texas Univ., Austin (USA). Center for Particle Theory

Texas Univ., Austin (USA). Center for Particle Theory

AbstractAbstract

[en] The recently derived ratio of three particle to two particle nonrelativistic binding energies for power law potentials in the leading order of the 1/D expansion, where D is the number of spatial dimensions, is used to investigate the ground state baryon spectrum. Using the phenomenologically successful Martin potential and the known meson masses, it is shown how the above ratio can be utilized to obtain accurate masses for baryons, even those containing light quarks. It is also mentioned how the shifted 1/D expansion may be used to study certain excited baryon states

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Feb 1987; 17 p; Available from NTIS, PC A02/MF A01; 1 as DE87006231; Portions of this document are illegible in microfiche products.

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AbstractAbstract

[en] In this paper it is shown that the fully anisotropic one-dimensional Kondo problem is exactly integrable. The authors obtain the energy of the ground state and that of elementary excitations in the thermodynamic limit. Connection with the eight-vertex model is also pointed out

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Journal Article

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AbstractAbstract

[en] It is shown by combining the Euler equation of density functional theory with the differential form of the virial theorem that the single-particle kinetic-energy density T

_{s}[ρ], on the minimum, and for N fermions, is a function solely of ρ, ρ' and x. This formal result is illustrated by taking the example of a harmonic oscillator with N levels filled. Model forms of T_{s}[ρ] and δT_{s}[ρ]/δρ then followPrimary Subject

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Journal Article

Journal

Europhysics Letters; CODEN EULEE; v. 11(7); p. 613-617

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AbstractAbstract

[en] The event structure in hadronic collisions is very complex, and the task of understanding this structure is correspondingly difficult. It is often convenient to imagine the physics subdivided into a number of components, like hard central interactions, initial and final state radiation, structure functions, beam jet structure and fragmentation. In this note we discuss so-called beam jet or minimum bias physics, but in a way that links it with the hard interaction physics. Specifically, we argue that hadronic events contain a varying number of semihard interactions, with average interaction rate given by perturbative QCD. The variation between different events results from Poissonian statistics for each impact parameter separately. Multiple interactions are to be seen as a natural consequence of the composite nature of hadrons, an impact parameter dependence as a result of the extended nature of hadrons. Experimental support for and consequences of this picture are outlined, in particular for Collider data. The studies reported here have been carried out in collaboration with Maria van Zijl, and are further described in Ref. 1

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Tran Thanh Van, J. (ed.); 679 p; ISBN 2-86332-056-4; ; 1988; p. 219-222; Editions Frontieres; Gif-sur-Yvette (France); 23. Moriond Meeting, Current issues in hadron physics; Les Arcs (France); 13-19 Mar 1988

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AbstractAbstract

[en] Hadron production in hadron-nucleus and nucleus-nucleus collisions is studied by a Monte-Carlo version of the dual multi-chain fragmentation model. The model takes into account leading order corrections due to the secondary interactions of low energy secondaries inside the target nucleus. An empirical formation time parameter is introduced and used to decide which secondaries interact again inside the target. Data for the multiparticle production in proton-nucleus and oxygen-nucleus interactions at 200 GeV/nucleon from different experiments are well described by the model and consistent with a formation time parameter of τc = 2 ± 1 fm. 20 refs., 13 figs

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Sep 1987; 34 p; CONTRACT AC02-89ER40486; NTIS, PC A03/MF A01 as DE90014688; OSTI; INIS; US Govt. Printing Office Dep

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Veneroni, M.; Balian, R.

Paris-11 Univ., 91 - Orsay (France). Inst. de Physique Nucleaire

Paris-11 Univ., 91 - Orsay (France). Inst. de Physique Nucleaire

AbstractAbstract

[en] The thermal TDHF equation is analyzed in the Liouville representation of quantum mechanics, where the matrix elements of the single-particle (s.p.) density ρ behave as classical dynamical variables. By introducing the Lie-Poisson bracket associated with the unitary group of the s.p. Hilbert space, we show that TDHF has a hamiltonian, but non-canonical, classical form. Within this Poisson structure, either the s.p. energy or the s.p. grand potential Ω(ρ) act as a Hamilton function. The Lyapunov stability of both the TDHF and RPA equations around a HF state then follows, since the HF approximation for thermal equilibrium is determined by minimizing Ω(ρ). The RPA matrix in the Liouville space is expressed as the product of the Poisson tensor with the HF stability matrix, interpreted as a metric tensor generated by the entropy. This factorization displays the roles of the energy and entropy terms arising from Ω(ρ) in the RPA dynamics, and it helps to construct the RPA modes. Several extensions are considered

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1989; 45 p; SACLAY-PHT--89-068

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AbstractAbstract

[en] Isovector giant multipole resonances in both spherical (

^{110,112}Sn) and deformed (^{160}Er) nuclei at high temperature and spin have been studied. In the ground state the giant gamma ray spectrum had proved to be a powerful tool in determining the nuclear shape. These experiments clearly show that the tin nucleus retained its spherical shape all the way to 130 MeV excitation energy. The giant dipole resonance energy decreased slightly with increasing temperature. The increase of the width with temperature was monotonic and given by a power law. The erbium nucleus retained its ground state prolate shape at 57.7 MeV excitation energy. At higher energies the shape becomes less prolate. It is difficult to say definitively if the nucleus becomes spherical or oblate at 74.4 MeV or at 90.5 MeV. The angular distribution of the E1 gamma rays from^{112}Sn was found to be isotropic. There was no conspicuous sign of the isovector giant quadrupole resonance in any of the three nuclei. A brief description of a new technique of pileup rejection has been includedPrimary Subject

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1987; 110 p; State Univ. of New York; Stony Brook, NY (USA); University Microfilms, PO Box 1764, Ann Arbor, MI 48106, Order No.88-01,252; Thesis (Ph. D.).

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Miscellaneous

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Thesis/Dissertation; Numerical Data

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Odyniec, G.

Lawrence Berkeley Lab., CA (USA). Funding organisation: USDOE, Washington, DC (USA)

Lawrence Berkeley Lab., CA (USA). Funding organisation: USDOE, Washington, DC (USA)

AbstractAbstract

[en] In experiments with oxygen (60 and 200 GeV/N) and sulphur (200 GeV/N) ions at CERNSPS, large energy densities of the order of 2--3 GeV/fm

_{3}have been observed, which according to QCD calculations, satisfy necessary conditions for the formation of a quark gluon plasma (QGP) phase. Under such conditions, colour would no longer be confined to hadronic dimensions, and quarks and gluons will propagate freely throughout an extended volume. Somehow lower energy densities, of the order of 0.7--1 GeV/fm_{3}, were observed in AGS experiments with 15 GeV/N silicon beams and heavy targets. These energy densities might be adequate for investigations of the pre-equilibrium stage, during which the momentum space distribution has been degradated from its initial value but is not yet thermal. First experimental results, available now, show promise of seeing signs of a new phase of matter. In this review the current status of the selective experimental results on strange-particle production, which are relevant to equilibration and QGP formation in nucleus-nucleus collisions, is presentedPrimary Subject

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Dec 1990; 22 p; International workshop on quark gluon plasma signatures; Strasbourg (France); 1-4 Oct 1990; CONF-9010320--2; CONTRACT AC03-76SF00098; OSTI as DE91011866; NTIS; INIS; US Govt. Printing Office Dep

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AbstractAbstract

[en] Production of mesons in hadronic collisions is a particularly interesting process - in particular since kinetic energy of the entrance channel is converted into hadron matter. The reaction mechanism via which this conversion of energy into specific quark-anti-quark systems proceeds is intimately connected to the coupling of nuclear and subnuclear degrees of freedom of complex hadrons. In the paper this relation will be illuminated and exemplified for a few specific reactions. The discussion will be restricted to light baryonic systems and to excitation energies up to about 1 GeV. In this energy domain various N*- and Δ*-excitations are accessible and in addition, various meson continua open up with increasing excitation energy

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Fleury, P; 230 p; ISBN 9971-50-677-7; ; 1988; p. 171-186; World Scientific Pub. Co; Teaneck, NJ (USA); Workshop on production and decay of light mesons; Paris (France); 3-4 Mar 1988; CONF-8803108--; World Scientific Pub. Co., 687 Hartwell Street, Teaneck, NJ 07666 (USA)

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