Investigating the Light Scalar Mesons

We first briefly review a treatment of the scalars in meson meson scattering based on a non-linear chiral Lagrangian, with unitarity implemented by a "local" modification of the scalar propagators. It is shown that the main results are confirmed by a treatment in the SU(3) linear sigma model in which unitarity is implemented "globally". Some remarks are made on the speculative subject of the scalars' quark structure.Comment: 9 pages,3 figures,talk at hadron2001, Protvin

Control of the geometric phase and pseudo-spin dynamics on coupled Bose-Einstein condensates

We describe the behavior of two coupled Bose-Einstein condensates in time-dependent (TD) trap potentials and TD Rabi (or tunneling) frequency, using the two-mode approach. Starting from Bloch states, we succeed to get analytical solutions for the TD Schroedinger equation and present a detailed analysis of the relative and geometric phases acquired by the wave function of the condensates, as well as their population imbalance. We also establish a connection between the geometric phases and constants of motion which characterize the dynamic of the system. Besides analyzing the affects of temporality on condensates that differs by hyperfine degrees of freedom (internal Josephson effect), we also do present a brief discussion of a one specie condensate in a double-well potential (external Josephson effect).Comment: 1 tex file and 11 figures in pdf forma

Dynamic response studies on aggregation and breakage dynamics of colloidal dispersions in stirred tanks

Aggregation and breakage of aggregates of fully destabilized polystyrene latex particles in turbulent flow was studied experimentally in both batch and continuous stirred tanks using small-angle static light scattering. It was found that the steady-state values of the root-mean-square radius of gyration are fully reversible upon changes of stirring speed as well as solid volume fraction. Steady-state values of the root-mean-square radius of gyration were decreasing with decreasing solid volume fraction as well as with increasing stirring speed. Moreover, it was found that the steady-state structure and shape of the aggregates is not influenced by the applied stirring speed

Can board environmental orientation improve U.S. firms' carbon performance? The mediating role of carbon strategy

Overwhelming evidence from prior research suggests a positive association between corporate board characteristics and carbon performance; however, very little is known about the mechanisms linking the two variables. This study attempts to fill this gap by developing and empirically testing a conceptual model that highlights the role of carbon strategy in the relationship between board environmental orientation (BEO) and carbon performance. We argue that BEO can directly and indirectly influence carbon performance through carbon strategy. Using structural equation modelling to analyse data consisting of 2,301 US firm-year observations over the 2005-2015 period, we find that the greater the BEO is, the better its carbon performance (i.e., lower greenhouse gas emissions). The results also provide evidence of the mediating effect of carbon strategy on the relationship between BEO and carbon performance. Splitting the sample into high and low carbon-intensive industries shows a partial mediation effect in high carbon-intensive industries and a full mediation effect in low carbon-intensive industries. The findings of the study and its implications for scholars, policy makers, managers, investors and environmentalists are discussed

Model for Small neutrino masses at the TeV Scale

We propose a model for neutrino mass generation in wich no physics beyond a TeV is required. We extend the standard model by adding two charged singlet fields with lepton number two. Dirac neutrino masses $m_{\nu_D} \leq MeV$ are generated at the one loop level. Small left handed majorana neutrino masses can be generated via the seesaw mechanism with right handed neutrino masses $M_R$ are of order TeV scale.Comment: 13 pages, 2 figure

Teleportation of a Zero-and One-photon Running Wave State by Projection Synthesis

We show how to teleport a running wave superposition of zero- and one-photon field state through the projection synthesis technique. The fidelity of the scheme is computed taking into account the noise introduced by dissipation and the efficiency of the detectors. These error sources have been introduced through a single general relationship between input and output operators.Comment: 11 pages, 1 figur

Energy in Topologically Massive Gravity

We define conserved gravitational charges in -cosmologically extended- topologically massive gravity, exhibit them in surface integral form about their de-Sitter or flat vacua and verify their correctness in terms of two basic types of solution.Comment: 6 page

Shear flow of non-Brownian rod-sphere mixtures near jamming

Varying particle shape provides a route to rationally design the viscosity and jamming of complex fluids. The underlying physical mechanisms, however, remain unexplored. Here we use the discrete element method, taking particle contact and hydrodynamic lubrication into account, to unveil the shear rheology of mixtures of frictionless non-Brownian spheres and rod-like (spherocylinders) particles in the dense regime of packing fraction. By increasing the aspect ratio of the rods, while keeping constant either the total (rods plus spheres) particle packing fraction and the rod-sphere mixing ratio, the viscosity $\eta$ of the mixture is observed to vary in a non-monotonical fashion. An initial decrease of viscosity with increasing aspect ratio is followed by a subsequent increase after that a minimum is reached when the rods have an aspect ratio of approximately $1.5.$ This minimum represents the absolute one, in the particular case of no spheres present in the system. A mechanistic interpretation of this discovery is provided in terms of packing and excluded-volume arguments

Unitarized pseudoscalar meson scattering amplitudes in three flavor linear sigma models

The three flavor linear sigma model is studied as a ``toy model'' for understanding the role of possible light scalar mesons in the \pi \pi, \pi K and \pi \eta scattering channels. The approach involves computing the tree level partial wave amplitude for each channel and unitarizing by a simple K-matrix prescription which does not introduce any new parameters. If the renormalizable version of the model is used there is only one free parameter. While this highly constrained version has the right general structure to explain \pi \pi scatteirng, it is ``not quite'' right. A reasonable fit can be made if the renormalizability (for the {\it effective} Lagrangian) is relaxed while chiral symmetry is maintained. The occurence of a Ramsauer Townsend mechanism for the f_0(980) region naturally emerges. The effect of unitarization is very important and leads to ``physical'' masses for the scalar nonet all less than about 1 GeV. The a_0(1450) and K_0^*(1430) appear to be ``outsiders'' in this picture and to require additional fields. Comparison is made with a scattering treatment using a more general non-linear sigma model approach. In addition some speculative remarks and a highly simplified larger toy model are devoted to the question of the quark substructure of the light scalar mesons