Coronal propagation of solar flare particles observed by satellite

Propagation of solar flare particles in corona was studied using the satellite data at the geostationary orbit. by selecting very fast rise time events only, the interplanetary propagation were assumed to be scatter free arrival. The results show that the propagation in corona does not depend on particle energy in 4 to 500 MeV protons, and the time delays from optical flare do not depend on the distance between the flare site and the base of the interplanetary magnetic field which connects to the Earth

Oscillating p-Branes

Coset methods are used to construct the action describing the dynamics associated with the spontaneous breaking of the Poincare symmetries of D dimensional space-time due to the embedding of a p-brane with codimension N=D-p-1. The resulting world volume action is an ISO(1,p+N) invariant generalization of the Nambu-Goto action in d=p+1 dimensional space-time. Analogous results are obtained for an AdS p-brane with codimension N embedded in D dimensional AdS space, yielding an SO(2,p+N) invariant version of the Nambu-Goto action in d=p+1 dimensional space-time. Attention is focused on a supersymmetric extension of the D=6 Minkowski space case with an embedded p=3 brane; a particular realization of which is provided by a non-BPS vortex. Here both the Nambu-Goto-Akulov-Volkov action and its dual tensor form are presented.Comment: 25 pages, no figure

Brane Vector Phenomenology

Local oscillations of the brane world are manifested as masssive vector fields. Their coupling to the Standard Model can be obtained using the method of nonlinear realizations of the spontaneously broken higher dimensional space-time symmetries, and to an extent, are model independent. Phenomenological limits on these vector field parameters are obtained using LEP collider data and dark matter constraints.Comment: 3 pages, 2 figures, late

Competition between Spin-Orbit Interaction and Zeeman Coupling in Rashba 2DEGs

We investigate systematically how the interplay between Rashba spin-orbit interaction and Zeeman coupling affects the electron transport and the spin dynamics in InGaAs-based 2D electron gases. From the quantitative analysis of the magnetoconductance, measured in the presence of an in-plane magnetic field, we conclude that this interplay results in a spin-induced breaking of time reversal symmetry and in an enhancement of the spin relaxation time. Both effects, due to a partial alignment of the electron spin along the applied magnetic field, are found to be in excellent agreement with recent theoretical predictions.Comment: 4 figures and 4 page

Statistical significance of fine structure in the frequency spectrum of Aharonov-Bohm conductance oscillations

We discuss a statistical analysis of Aharonov-Bohm conductance oscillations measured in a two-dimensional ring, in the presence of Rashba spin-orbit interaction. Measurements performed at different values of gate voltage are used to calculate the ensemble-averaged modulus of the Fourier spectrum and, at each frequency, the standard deviation associated to the average. This allows us to prove the statistical significance of a splitting that we observe in the h/e peak of the averaged spectrum. Our work illustrates in detail the role of sample specific effects on the frequency spectrum of Aharonov-Bohm conductance oscillations and it demonstrates how fine structures of a different physical origin can be discriminated from sample specific features.Comment: accepted for publication in PR

Application of Hamamatsu MPPC to T2K Neutrino Detectors

A special type of Hamamatsu MPPC, with a sensitive area of 1.3x1.3mm^2 containing 667 pixels with 50x50um^2 each, has been developed for the near neutrino detector in the T2K long baseline neutrino experiment. About 60 000 MPPCs will be used in total to read out the plastic scintillator detectors with wavelength shifting fibers. We report on the basic performance of MPPCs produced for T2K.Comment: Contribution to the proceedings of NDIP 2008, Aix-les-Bains, France, June 15-20, 200

Nonlinear realization of local symmetries of AdS space

Coset methods are used to construct the action describing the dynamics associated with the spontaneous breaking of the local symmetries of AdS_{d+1} space due to the embedding of an AdS_d brane. The resulting action is an SO(2,d) invariant AdS form of the Einstein-Hilbert action, which in addition to the AdS_d gravitational vielbein, also includes a massive vector field localized on the brane. Its long wavelength dynamics is the same as a massive Abelian vector field coupled to gravity in AdS_d space.Comment: 17 page

Effect of an InP/In0.53_{0.53}Ga0.47_{0.47}As Interface on Spin-orbit Interaction in In0.52_{0.52}Al0.48_{0.48}As/In0.53_{0.53}Ga0.47_{0.47}As Heterostructures

We report the effect of the insertion of an InP/In$_{0.53}$Ga$_{47}$As Interface on Rashba spin-orbit interaction in In$_{0.52}$Al$_{0.48}$As/In$_{0.53}$Ga$_{0.47}$As quantum wells. A small spin split-off energy in InP produces a very intriguing band lineup in the valence bands in this system. With or without this InP layer above the In$_{0.53}$Ga$_{47}$As well, the overall values of the spin-orbit coupling constant $\alpha$ turned out to be enhanced or diminished for samples with the front- or back-doping position, respectively. These experimental results, using weak antilocalization analysis, are compared with the results of the $\mathbf{k\cdot p}$ theory. The actual conditions of the interfaces and materials should account for the quantitative difference in magnitude between the measurements and calculations.Comment: Submitted for publication; v2 to adjust Eq.6; v3 to correct the figure file name; v4, a revised version accepted for publication in Phys. Rev.