Symmetry restrictions in the chirality dependence of physical properties of single-wall nanotubes

We investigate the chirality dependence of physical properties of nanotubes which are wrapped by the planar hexagonal lattice including graphite and boron nitride sheet, and reveal its symmetry origin. The observables under consideration are of scalar, vector, and tensor types. These exact chirality dependences obtained are useful to verify the experimental and numerical results and propose accurate empirical formulas. Some important features of physical quantities can also be extracted by considering the symmetry restrictions without complicated calculations.

Study of nucleon resonances in a chiral quark model via eta productions

In this report we investigate eta-meson productions oil the proton via electromagnetic and hadron probes in a chiral quark model approach. The observables, such as, differential cross section and beam asymmetry for the two productions are calculated and compared with the experiment. The five known resonances S-11(1535) S-11(1650); P-13(1720) D-13(1520), and F-15(1680) are found to be dominant in the reaction mech-anisms in both channels. Significant, contribution from a new S-11 resonances are deduced. For the so-called "missing resonances", no evidence is found within the investigated reactions. The partial wave amplitudes for pi(-)p -> eta n are also presented.

Rotation-driven prolate-to-oblate shape phase transition in W-190: A projected shell model study

A shape phase transition is demonstrated to occur in W-190 by applying the projected shell model, which goes beyond the usual mean-field approximation. Rotation alignment of neutrons in the high-j, i(13/2) orbital drives the yrast sequence of the system, changing suddenly from prolate to oblate shape at angular momentum 10h. We propose observables to test the picture.

STUDIES FOR THE EQUATION OF STATE IN THE ISOSPIN ASYMMETRICAL NUCLEAR INTERACTIONS

In order to determine the equation of state in the isospin asymmetrical nuclear interactions, we have found the observables for extracting the information of them within the isospin-dependent quantum molecular dynamics in recent years. The several sensitive probes for extracting the information of the in-medium nucleon-nucleon cross section and the symmetry potential have found; meanwhile, their mechanisms are investigated in more details. The main point in this paper gives the summary for above probes and their outlook in the future.

Systematics of central heavy ion collisions in the 1A GeV regime

Using the large acceptance apparatus FOPI, we study central collisions in the reactions (energies in A GeV are given in parentheses): Ca-40 + Ca-40 (0.4, 0.6, 0.8, 1.0, 1.5, 1.93), Ni-58 + Ni-58 (0.15, 0.25, 0.4), Ru-96+Ru-96 (0.4, 1.0. 1.5), (96)zr+(96)zr 1.0, 1.5), Xe-129+CsI (0.15, 0.25, 0.4), Au-197 + Au-197 (0.09, 0.12, 0.15, 0.25, 0.4, 0.6, 0.8, 1.0, 1.2, 1.5). The observables include cluster multiplicities, longitudinal and transverse rapidity distributions and stopping, and radial flow. The data are compared to earlier data where possible and to transport model simulations. (C) 2010 Elsevier B.V. All rights reserved.

Isobaric yield ratios and the symmetry energy in heavy-ion reactions near the Fermi energy

The relative isobaric yields of fragments produced in a series of heavy-ion-induced multifragmentation reactions have been analyzed in the framework of a modified Fisher model, primarily to determine the ratio of the symmetry energy coefficient to the temperature, a(sym)/T, as a function of fragment mass A. The extracted values increase from 5 to similar to 16 as A increases from 9 to 37. These values have been compared to the results of calculations using the antisymmetrized molecular dynamics (AMD) model together with the statistical decay code GEMINI. The calculated ratios are in good agreement with those extracted from the experiment. In contrast, the values extracted from the ratios of the primary isobars from the AMD model calculation are similar to 4 to 5 and show little variation with A. This observation indicates that the value of the symmetry energy coefficient derived from final fragment observables may be significantly different than the actual value at the time of fragment formation. The experimentally observed pairing effect is also studied within the same simulations. The Coulomb coefficient is also discussed.

Nucleon form factors in a light-cone quark model with two-photon exchange

We estimate the two-photon exchange corrections to both proton and neutron electromagnetic physical observables in a relativistic light cone quark model At a fixed Q(2) the corrections are found to be small in magnitudes. but strongly dependent oil scattering angle Our results are comparable to those obtained from simple hadronic model in the medium momentum transfer region (C) 2009 Elsevier B V All rights reserved