Double quantization on the coadjoint representation of sl(n)

For we construct a two parametric -invariant family of algebras, , that is a quantization of the function algebra on the coadjoint representation. Along the parameter t the family gives a quantization of the Lie bracket. This family induces a two parametric -invariant quantization on the maximal orbits, which includes a quantization of the Kirillov-Kostant-Souriau bracket. Yet we construct a quantum de Rham complex on .     

Determination of dislocation damping in copper single crystals with stress pulse method

Dislocation damping in copper single crystals was determined by the stress pulse method. For this purpose very short stress pulses were used, maximum length 30 s, by which loading conditions of a metallic matrix in the frontal region of a propagating brittle crack were simulated. At loading by these very short stress waves, strain rates above 10⁴ s^–1 are achieved, however, the strain rate during loading is not constant. Therefore a technique was elaborated that enables to compare the measured results of mechanical characteristics with very short stress pulses ( const.) with results obtained on a device with a constant strain rate of the specimen. With the use of the dependence = ( ) the existence of damping mechanisms of a viscous character was proved and the damping coefficientB determined. These results agree with theoretical assumptions in [10,20] about the probable mechanical behaviour in the region of the propagating brittle crack.ikova 22, Brno, Czechoslovakia.     

Tunneling Across an Inhomogeneous Delta-Barrier

The authors deal with the tunneling of electrons across an inhomogeneous delta-barrier defined by the potential energy (where 0$$ " align="middle" border="0"> and 0$$ " align="middle" border="0"> are two constants). In particular, the perpendicular incidence of an electron with a given value of the wave vector is considered. The electron is forward-scattered into the region behind the barrier (region 2: 0$$ " align="middle" border="0"> ), i. e. the wave function is composed of plane waves with all wave vectors such that and \left. 0 \right)} $$ " align="middle" border="0"> ) (where ). Therefore, if 0$$ " align="middle" border="0"> , the wave function of the electron is represented as , where . An approximate formula is derived for the amplitude . The authors pay a special attention to the flow density and calculate this function in two cases: 1. for the plane and 2. for high values of is the diffraction angle). The authors discuss the relevance of their diffraction problem in a prospective quantum-mechanical theory of the tunneling of electrons across a randomly inhomogeneous Schottky barrier.     

Minimal Model Fusion Rules From 2-Groups

The fusion rules for the (p,q)-minimal model representations of the Virasoro algebra are shown to come from the group in the following manner. There is a partition into disjoint subsets and a bijection between and the sectors of the (p,q)-minimal model such that the fusion rules correspond to where .     

Minimal supersymmetric standard model with the gauge mediated supersymmetry breaking and the neutrinoless double-beta decay

Neutrinoless double-beta decay within Minimal Supersymmetric Standard Model with gauge mediated supersymmetry breaking is considered. Limits on R-parity breaking constant coming from non-observability of 0 in ⁷⁶Ge are found. The dependence of on different parameters at the messenger scale M are shown, with special attention paid to nuclear part of calculations. We have found that strongly depends on the effective supersymmetry breaking scale only and deduced limits imposed on this non-standard parameter by the germanium experiment.     

Diquark Model for J/ψ Baryonic Decays

The baryonic decays of J/ provide a new way to study the internal structure of baryons. We apply a simple diquark model to the calculation of the decay cross-sections for the reactions J/ , N^*(1440), ^*N^*, and ⁰⁰. The results are different from those given by the ordinary constituent quark model. Hence these reactions may provide a new check of two different pictures for the baryons.     

Poisson Structures for Dispersionless Integrable Systems and Associated W-Algebras

In analogy to the KP theory, the second Poisson structure for the dispersionless KP hierarchy can be defined on the space of commutative pseudodifferential operators . The reduction of the Poisson structure to the symplectic submanifold gives rise to W-algebras. In this Letter, we discuss properties of this Poisson structure, its Miura transformation and reductions. We are particularly interested in the following two cases: (a) L is pure polynomial in p with multiple roots and (b) L has multiple poles at finite distance. The w-algebra corresponding to the case (a) is defined as , where means the multiplicity of roots and to the case (b) is defined by where is the multiplicity of poles. We prove that -algebra is isomorphic via a transformation to U(1) with m= . We also give the explicit free fields representations for these W-algebras.     

Quantum integrable systems and oscillator representations of c n

Solutions of the Yang-Baxter equation with spectral parameter for systems with in-variance under a Lie algebra and for which the quantum space is a Hilbert space different from the auxiliary space are studied. In particular, for the case of =c_n= sp (2n, ), solutions on infinite-dimensional state spaces are constructed.     

Universal Feynman-Yang scaling for hadrons frome + e −,\bar pp andep collisions

An analysis of the single-particle distribution of inclusive at in terms of the covariant Boltzmann factor indicates that the Feynman-Yang scaling holds, the temperature ofW being 0.188 GeV. The specific central particle density ofW is found to be the same as andK ⁰ production at the same energy.     

Spin-orbit splitting in σ-hypernuclei

The shell model analysis of experimental 0⁺, 2⁺ spectra of and as obtained from (K ^–, ⁺) in-flight and stoppedK ^– reactions, is performed. It suggests a large (twice that for nucleons) spin-orbit splitting of hyperon levelsp _3/2 andp _1/2. Certain constraints on effective central N interaction arise, as well. Some experiments are put forward to further test this value and to extend it to hypernuclei.Presented at the symposium Mesons and Light Nuclei, Bechyn, Czechoslovakia, May 27–June 1, 1985.