Effects of ground-state correlations on 2νββ decay rates and limitations of the QRPA approach

Half-lives of the 2νββ decay are calculated in the proton-neutron QRPA for⁷⁶Ge,⁸²Se,¹⁰⁰Mo,^128,130Te,¹³⁶Xe and¹⁵⁰Nd. The strength of the particle-particle interaction, which plays a decisive role for a reliable evaluation of the half-lives, is determined from a QRPA calculation of singleβ ⁺ decays. The 2ν decay rates calculated with the interaction strength fitted in this way are strongly suppressed and found to be consistent with the existing experimental data. Effects of the ground-state correlations on the suppression are investigated. On the other hand, the present calculation indicates limitations of the QRPA approach.     

Linear dependence of stationary distributions in ergodic Markov decision processes

In ergodic MDPs we consider stationary distributions of policies that coincide in all but n states, in which one of two possible actions is chosen. We give conditions and formulas for linear dependence of the stationary distributions of n+2 such policies, and show some results about combinations and mixtures of policies.     

Oil Migration in Chocolate

Oil migration in filled chocolates limits shelf life due to texture changes and loss of visual appeal. Spatial and temporal oil concentration changes of a two-layer chocolate and peanut butter filling system, which models a filled chocolate, were monitored by magnetic resonance imaging. Formulations of chocolate varied with respect to particle size, milk fat content and emulsifier level. Sorption-time experimental data was used to establish the best fit diffusion coefficient for a Fickian diffusion model. On the basis of the comparison of spatial experimental data to the model, Fickian diffusion alone does not account for oil migration. Authors' address: Michael J. McCarthy, Department of Food Science and Technology, University of California, One Shields Avenue, Davis, CA 95616, USA     

Synergetic information versus Shannon information in self-organizing systems

We discuss how synergetic information, i.e. the compressed Shannon information of the order parameters, which is produced by the cooperativity of the system, can be determined experimentally, especially in fluids.     

Out of Equilibrium Correlations in the XY Chain

We study the transversal spin–spin correlations in the non-equilibrium steady state of the XY chain constructed by coupling a finite cutout of the chain to the two infinite parts to its left and right acting as thermal reservoirs at different temperatures. We prove that the spatial decay of these correlations is at least exponentially fast.