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An α-cluster model is applied to study low-lying spectrum of the Λ9Be hypernicleus. The ααΛ three-body problem is numerically solved by the Faddeev equations in configuration space using phenomenological pair potentials. Found is a set of the potentials that reproduces experimental data for the ground state (1+/2) binding energy and excitation energy of the 5+/2 and 3+/2 states, simultaneously. This set includes the Ali-Bodmer potential of version “e” for αα and modified Tang-Herndon potential for αΛ interactions. The spin-orbit αΛ interaction is given by modified Scheerbaum potential. Low-lying energy levels are evaluated applying a variant of the analytical continuation method in coupling constant, and the experimental data for excitation energies are well reproduced by our calculations. This result improves previous α-cluster calculations. It is shown that the spectral properties of Λ9Be can be classified as an analog of 9Be spectrum with the exception of several “genuine hypernuclear states”, which agrees qualitatively with previous studies. The energy splitting of spin-flip doublet (9+/2 , 7+/2) is predicted.

A high quality beam of linearly polarized photons of several GeV will become available with the coherent bremsstrahlung technique at JLab. We have developed a polarimeter which requires about two meters of the beam line, has an analyzing power of 20% and an efficiency of 0.02%. The layout and first of polarimeter test on the laser back-scattering photon beamat SPring-8/LEPS are presented. [ABSTRACT FROM AUTHOR]

The configuration-space Faddeev equations are derived for p-d scattering taking into account the difference in interaction between the participant particles. Appropriate modifications have been made in the well-known configuration-space equations for n-d scattering. To show the effect of these modifications, the s-wave calculations are performed for bound state and scattering problems. We model the charge symmetry breaking effect for 3H and 3He with a modified Malfliet-Tjon MT I-III potential. Results obtained for elastic n-d and p-d scattering at Elab=14.1 MeV are compared with our prediction (Ref. [1]) and those of the Los-Alamos/Iowa group (Ref. [2]) .

Formalism of the configuration-space Faddeev equations is applied to analyze the bound state problem of ΛNN system. The simulated NSC97f potential for ΛN interaction and semi-realistic NN potentials are used for calculations. We predict a broad Λnn resonance near threshold. A spin dependent three-body ΛNN potential has been proposed to explain experimental evidence for Λ3 n bound state. The potential is defined by a Gaussian function of a hyper-radius. It was found that such potential with appropriate spin dependence does not support a bound state of Λ3 n. A short range form of the potential generates non-physical solutions of the Faddeev equations.

The three-body approach based on the configuration space Faddeev equations for systems of non-identical particles is proposed to describe light hypernuclei (A=6,7, S=-1) with α particle clustering. We focus on the model (α +Λ) + n + n for Λ7He hypernucleus for which the first experimental data have been recently reported. New evaluation for hyperon binding energy in Λ7He is done by using a relation between energies of the spin doublet (1−,2−) of Λ6He and the Λ7He ground state. Energies of low-lying levels of Λ6He hypernucleus are calculated within the cluster α + Λ + n model.

The three-body kaonic K̅pp and K̅K̅p clusters are studied using the method of hyperspherical harmonics (HH) in momentum representation and differential Faddeev equations (DFE). We use different NN and K̅N interactions. Results obtained by the methods of HH and DFE are in reasonable agreement. The binding energy and the width show very strong dependence on the K̅N potential. We have two different classes of results: the results based on phenomenological strong K̅N potential, and the results obtained with much weaker chiral SU(3)-based K̅N potential.

The paradigm of ΛCDM cosmology works impressively well and with the concept of inflation it explains the universe after the time of decoupling. However there are still a few concerns; after much effort there is no detection of dark matter and there are significant problems in the theoretical description of dark energy. We will consider a variant of the cosmological spherical shell model, within FRW formalism and will compare it with the standard ΛCDM model. We will show that our new topological model satisfies cosmological principles and is consistent with all observable data, but that it may require new interpretation for some data. Considered will be constraints imposed on the model, as for instance the range for the size and allowed thickness of the shell, by the supernovae luminosity distance and CMB data. In this model propagation of the light is confined along the shell, which has as a consequence that observed CMB originated from one point or a limited space region. It allows to interpret the uniformity of the CMB without inflation scenario. In addition this removes any constraints on the uniformity of the universe at the early stage and opens a possibility that the universe was not uniform and that creation of galaxies and large structures is due to the inhomogeneities that originated in the Big Bang.

Abstract: We model an InAs/GaAs quantum dot (QD) with a single sub-band approach and an energy dependent effective electron mass. Confined states of carriers are formed by the band-gap potential. An additional potential is included in the model to simulate the combined effect of strains and piezoelectricity. It is shown that this effect may be taken into account in an effective manner. The model allows us to reproduce the results of ab initio calculations. To prove the adequacy of our model, we compare the results obtained for energy spectra of few electrons, tunneling into InAs/GaAs QD, with experimental capacitance–gate-voltage data. The non-parabolic effect taken into account in this calculation is quite visible for QD sizes considered. We discuss the possibility to describe the CV experimental data with electron confinement obtained from realistic model calculations, as well as limitations of these models in the case of extremely small QD size. [Copyright &y& Elsevier]