The Gamow-Teller States in Relativistic Nuclear Models

The Gamow-Teller(GT) states are investigated in relativistic models. The Landau-Migdal(LM) parameter is introduced in the Lagrangian as a contact term with the pseudo-vector coupling. In the relativistic model the total GT strength in the nucleon space is quenched by about 12% in nuclear matter and by about 6% in finite nuclei, compared with the one of the Ikeda-Fujii-Fujita sum rule. The quenched amount is taken by nucleon-antinucleon excitations in the time-like region. Because of the quenching, the relativistic model requires a larger value of the LM parameter than non-relativistic models in describing the excitation energy of the GT state. The Pauli blocking terms are not important for the description of the GT states.Comment: REVTeX4, no figure

About the maximal rank of 3-tensors over the real and the complex number field

High dimensional array data, tensor data, is becoming important in recent days. Then maximal rank of tensors is important in theory and applications. In this paper we consider the maximal rank of 3 tensors. It can be attacked from various viewpoints, however, we trace the method of Atkinson-Stephens(1979) and Atkinson-Lloyd(1980). They treated the problem in the complex field, and we will present various bounds over the real field by proving several lemmas and propositions, which is real counterparts of their results.Comment: 13 pages, no figure v2: correction and improvemen

Multistable attractors in a network of phase oscillators with three-body interaction

Three-body interactions have been found in physics, biology, and sociology. To investigate their effect on dynamical systems, as a first step, we study numerically and theoretically a system of phase oscillators with three-body interaction. As a result, an infinite number of multistable synchronized states appear above a critical coupling strength, while a stable incoherent state always exists for any coupling strength. Owing to the infinite multistability, the degree of synchrony in asymptotic state can vary continuously within some range depending on the initial phase pattern.Comment: 5 pages, 3 figure

Neutrino Nucleus Reactions based on New Shell Model Hamiltonians

A new shell model Hamiltonian for p-shell nuclei which properly takes into account important roles of spin-isospin interactions is used to obtain cross sections of neutrino-^12C reactions induced by decay-at-rest (DAR) neutrinos as well as supernona neutrinos. Branching ratios to various decay channels are calculated by the Hauser-Feshbach theory. Neutrino-^4He reactions are also investigated by using recent shell model Hamiltonians. The reaction cross sections are found to be enhanced for both ^12C and ^4He compared with previous calculations. As an interesting consequence of this, a possible enhancement of the production yields of light elements, ^7Li and ^11B, during supernova explosions is pointed out.Comment: 11 pages, 14 eps-figures, to be published in Physical Review C (in press

Melting Crystal, Quantum Torus and Toda Hierarchy

Searching for the integrable structures of supersymmetric gauge theories and topological strings, we study melting crystal, which is known as random plane partition, from the viewpoint of integrable systems. We show that a series of partition functions of melting crystals gives rise to a tau function of the one-dimensional Toda hierarchy, where the models are defined by adding suitable potentials, endowed with a series of coupling constants, to the standard statistical weight. These potentials can be converted to a commutative sub-algebra of quantum torus Lie algebra. This perspective reveals a remarkable connection between random plane partition and quantum torus Lie algebra, and substantially enables to prove the statement. Based on the result, we briefly argue the integrable structures of five-dimensional $\mathcal{N}=1$ supersymmetric gauge theories and $A$-model topological strings. The aforementioned potentials correspond to gauge theory observables analogous to the Wilson loops, and thereby the partition functions are translated in the gauge theory to generating functions of their correlators. In topological strings, we particularly comment on a possibility of topology change caused by condensation of these observables, giving a simple example.Comment: Final version to be published in Commun. Math. Phys. . A new section is added and devoted to Conclusion and discussion, where, in particular, a possible relation with the generating function of the absolute Gromov-Witten invariants on CP^1 is commented. Two references are added. Typos are corrected. 32 pages. 4 figure

Building Innovation System for the Diffusion of Renewable EnergyTechnology: Practices in Ethiopia and Bangladesh

AbstractThe diffusion of renewable energy technologies (RETs) has been progressing very slowly in global scope, particularly in developing countries where the diffusion challenges for renewable are greater. Among potential actors in the promotion and diffusion of rural-based renewable energy innovations, NGOs and NPOs have been mentioned as promising actors. However, empirical studies that show the role of the actors and the way they can besystem builders by diffusing existing technologies have been very rare. This paper discusses the practices of an NGO in Ethiopia (Solar Energy Foundation) and an NPO in Bangladesh (Grameen Shakti) and showshowlocal technological innovation systems can be built bykey actors in the context of developing countries. The studysheds light on the process of system building for accelerated diffusion of RETs in the context of developing countries. Using a theoretical framework, we compared the approach, technology adoption trend (solar home systems diffusion), and common challenges facing both actors in their respective countries. The two empirical cases which are in different geographical contexts provided lessons on thesimilarities and differences of system building practices and emerging innovation systems for diffusion of RETs in developing countries

Itinerant Ferromagnetism in layered crystals LaCoOX (X = P, As)

The electronic and magnetic properties of cobalt-based layered oxypnictides, LaCoOX (X = P, As), are investigated. LaCoOP and LaCoOAs show metallic type conduction, and the Fermi edge is observed by hard x-ray photoelectron spectroscopy. Ferromagnetic transitions occur at 43 K for LaCoOP and 66 K for LaCoOAs. Above the transition temperatures, temperature dependence of the magnetic susceptibility follows the Curie-Weiss law. X-ray magnetic circular dichroism (XMCD) is observed at the Co L2,3-edge, but not at the other edges. The calculated electronic structure shows a spin polarized ground state. These results indicate that LaCoOX are itinerant ferromagnets and suggest that their magnetic properties are governed by spin fluctuation.Comment: 16 pages, 9 figures, Physical Review B, in press. Received 17 February 2008. Accepted 29 May 200

Hyperfine Anomaly of Be Isotopes and Anomalous Large Anomaly in 11^{11}Be

A new result of investigations of the hyperfine structure (hfs) anomaly in Be isotopes is presented. The hfs constant for $^{11}$Be is obtained by using the core plus neutron type wave function: $|2s_{1\over 2}>+|1d_{5\over2}\times 2^+ ; {1/2}^{+}>$. A large hfs anomaly of $^{11}$Be is found, which is mainly due to a large radius of the halo single particle state.Comment: 14 pages, Late