Dispersion Relations Explaining OPERA Data From Deformed Lorentz Transformation

OPERA collaboration has reported evidence of superluminal phenomenon for neutrinos. One of the possible ways to explain the superluminality is to have Lorentz symmetry violated. It has been shown that dispersion relations put forwards has the problem of physics laws vary in different inertial frames leading to conflicting results on Cherenkov-like radiation, pion decay and high energy neutrino cosmic ray. For theories with deformed Lorentz symmetry, by modifying conservation laws corresponding to energy and momentum in the usual Lorentz invariant theory, it is possible to have superluminal effect and at the same time avoid to have conflicts encountered in Lorentz violating theories. We study dispersion relations from deformed Lorentz symmetry. We find that it is possible to have dispersion relations which can be consistent with data on neutrinos. We show that once the superluminality $\delta v$ as a function of energy is known the corresponding dispersion relation in the deformed Lorentz symmetry can be determined.Comment: 8 pages, 2 figures. Several typos corrected and some references adde

Coil-to-globule transition by dissipative particle dynamics simulation

The dynamics of a collapsing polymer under a temperature quench in dilute solution is investigated by dissipative particles dynamics. Hydrodynamic interactions and many-body interaction are preserved naturally by incorporating explicit solvent particles in this approach. Our simulation suggests a four-stage collapse pathway: localized clusters formation, cluster coarsening in situ, coarsening involving global backbone conformation change into a crumpled globule, and compaction of the globule. For all the quench depths and chain lengths used in our study, collapse proceeds without the chain getting trapped in a metastable “sausage” configuration, as reported in some earlier studies. We obtain the time scales for each of the first three stages, as well as its scaling with the quench depths ξ and chain lengths N. The total collapse time scales as τ_c ~ ξ^(−0.46 ± 0.04)N^(0.98 ± 0.09), with the quench depth and degree of polymerization

The effects of local hydrodynamics on mass transfer in disordered porous media

Interfacial mass transfer in disordered media was studied experimentally and numerically. The dissolution of solid benzoic acid spheres in packed columns showed the existence of spatial variations in mass transfer coefficients in monodisperse and polydisperse packings at the same overall Peclet number. The concept of a local Peclet number (single-particle average) was introduced to quantify the effect of local hydrodynamics on local mass transfer. Correlations between Sherwood number and Peclet number having the form Shi=A·(xiPe)m were used to quantify data from various sites in each packing. These experiments also showed that the exponent m varies significantly from site to site. Stochastic simulations of interfacial dissolution in two-dimensional porous media were conducted, and mass-transfer-coefficient distributions similar to experimental results were obtained. The local velocity profiles available in the numerical simulations allowed a more detailed analysis to be made of local hydrodynamics and their effects on mass transfer. These result showed that mass transfer is affected by both large- and small-scale structure in the material. The large-scale structure affects the magnitude of local velocities and the small-scale structure (e.g., gap spacing between neighboring spheres) affects the shape of local streamlines. Particles exposed to large velocity gradients at their surface and/or particles for which streamline closely hugged their surfaces were observed to have higher rates of mass transfer. The correlation accuracy can be improved when two parameters (local Peclet number x·Pe and exponent z·m) were used in correlation such as Sh=A·(xiPe)mzi. Further analysis showed that there is a strong correlation between xi and zi and only one variable is needed to correct both the local Peclet number and the exponent term. A correlation was presented as Sh=A(xiPe)0.8965mxi-0.158 for the specific data generated in this work. In the future, the use of distributed mass-transfer correlations similar to those presented in this study may improve modeling of NAPL remediation