What can break the Wandzura--Wilczek relation?

We analyze the breaking of the Wandzura-Wilczek relation for the g_2 structure function, emphasizing its connection with transverse momentum dependent parton distribution functions. We find that the relation is broken by two distinct twist-3 terms, and clarify how these can be separated in measurements of double-spin asymmetries in semi-inclusive deep inelastic scattering. Through a quantitative analysis of available g_2 data we also show that the breaking of the Wandzura-Wilczek relation can be as large as 15-30% of the size of g_2.Comment: 12 page

Modulated Amplitude Waves in Bose-Einstein Condensates

We analyze spatio-temporal structures in the Gross-Pitaevskii equation to study the dynamics of quasi-one-dimensional Bose-Einstein condensates (BECs) with mean-field interactions. A coherent structure ansatz yields a parametrically forced nonlinear oscillator, to which we apply Lindstedt's method and multiple-scale perturbation theory to determine the dependence of the intensity of periodic orbits (``modulated amplitude waves'') on their wave number. We explore BEC band structure in detail using Hamiltonian perturbation theory and supporting numerical simulations.Comment: 5 pages, 4 figs, revtex, final form of paper, to appear in PRE (forgot to include \bibliography command in last update, so this is a correction of that; the bibliography is hence present again

An Automatic Invisible Axion In The SUSY Preon Model

It is shown that the recently proposed preon model which provides a unified origin of the diverse mass scale and an explanation of family replication as well as of inter-family mass-hierarchy, possesses a Peccei-Quinn symmetry whose spontaneous breaking leads to an automatic invisible axion. Existence of the PQ-symmetry is simply a consequence of supersymmetry and requirement of minimality in the field-content and interactions, which propose that the lagrangian should possess only those terms which are dictated by the gauge principle and no others. In addition to the axion, the model also generates two superlight Goldstone bosons and their superpartners which are cosmologically safe.Comment: (TeX file) 16 Page

CONTROL OF COLUMNAR-TO-EQUIAXED TRANSITION IN CONTINUOUS CASTING OF 16% Cr STAINLESS STEEL

In continuous casting of 16%Cr ferritic stainless steel, columnar grains undesirably forming among equiaxedgrains make non-uniform microstructure and degrade ridging property. Since this phenomenon results fromthe change of solidification condition during continuous casting, we focused on Cellular-to-Equiaxed Transition(CET) in continuous casting of 16%Cr ferritic stainless steel to control the microstructure of as-cast slab.In order to find the CET condition, we carried out the one dimensional heat transfer analysis of the melt, andpredicted the CET condition by Hunt’s model. It was revealed that the secondary columnar grains usually formedat 0.5~0.8 solid fractions, and the formation of them resulted from a steep increase of G/V1/2 value as themelt was getting out of EMS field; however the increase of G/V1/2 was readily controlled by changing EMSpattern and the secondary cooling intensity. In result, secondary columnar grains were eliminated by optimizingthe upper and lower EMS intensity, and increasing secondary cooling intensity. We also investigatedthe effect of solidification parameters including superheat and casting speed as CET condition in continuouscasting process, and the results were also discussed by the terms of thermal condition of melt

Solar Neutrino Masses and Mixing from Bilinear R-Parity Broken Supersymmetry: Analytical versus Numerical Results

We give an analytical calculation of solar neutrino masses and mixing at one-loop order within bilinear R-parity breaking supersymmetry, and compare our results to the exact numerical calculation. Our method is based on a systematic perturbative expansion of R-parity violating vertices to leading order. We find in general quite good agreement between approximate and full numerical calculation, but the approximate expressions are much simpler to implement. Our formalism works especially well for the case of the large mixing angle MSW solution (LMA-MSW), now strongly favoured by the recent KamLAND reactor neutrino data.Comment: 34 pages, 14 ps figs, some clarifying comments adde