27 research outputs found
Resonance Production
Recent results on rho(770)^0, K(892)^*0, f_0(980), phi(1020), Delta(1232)^++,
and Lambda(1520) production in A+A and p+p collisions at SPS and RHIC energies
are presented. These resonances are measured via their hadronic decay channels
and used as a sensitive tool to examine the collision dynamics in the hadronic
medium through their decay and regeneration. The modification of resonance
mass, width, and shape due to phase space and dynamical effects are discussed.Comment: 8 pages, 10 figures, proceedings of the Quark Matter 2004, in
Oakland, California, to be published in Journal of Physics G: Nuclear and
Particle Physic
A global fit of and elastic scattering in ChPT with dispersion relations
We apply the one-loop results of the ChPT suplemented
with the inverse amplitude method to fit the available experimental data on
and scattering. With esentially only three parameters we
describe accurately data corresponding to six different channels, namely
and . In addition we
reproduce the first resonances of the and channel with the
right mass corresponding to the and the particles.Comment: 19 pages, 5 figures available on request, FT/UCM/10/9
Isospin breaking corrections to low-energy pi-K scattering
We evaluate the matrix elements for the processes pi^0 K^0 -> pi^0 K^0 and
pi^- K^+ -> pi^0 K^0 in the presence of isospin breaking terms at leading and
next-to-leading order. As a direct application the releveant combination of the
S-wave scattering lengths involved in the pion-kaon atom lifetime is
determined. We discuss the sensitivity of the results with respect to the input
parameters.Comment: 33 pages, plain latex, 2 figure
- scattering lengths at finite temperature in the Nambu--Jona-Lasinio model
The transition amplitude for scattering is evaluated within the SU(3)
Nambu--Jona-Lasinio model. Ordering terms according to the expansion in
leads to a box-like diagram, channel diagrams that admit scalar isoscalar
exchanges, and a channel exchange of a scalar isodoublet
that has quantum numbers corresponding to the . Both
the Pauli-Villars and O(3) regularization procedures are used to evaluate the
T=0 values of the scattering lengths and . The
finite temperature dependence is studied. We find that the variation in the
channel in the calculation of leads to a change in of a
factor of about two over the temperature range of T=150 MeV
Do Firms Issuing Equity Manage their Earnings? Evidence from the Property-Casualty Insurance Industry
Genetic and environmental influences on fruit and vegetable consumption and depression in older adults
Background: Prior work suggests that higher fruit and vegetable consumption may protect against depression in older adults. Better understanding of the influence of genetic and environmental factors on fruit and vegetable intakes may lead to the design of more effective dietary strategies to increase intakes. In turn this may reduce the occurrence of depression in older adults. Objectives: The primary aim of this study is to estimate the genetic and environmental influences on the consumption of fruit and vegetables in older adults. The secondary aim is an exploratory analysis into possible shared genetic influences on fruit and vegetable intakes and depression. Methods: Analysis of observational data from 374 twins (67.1% female; 208 monozygotic (MZ); 166 dizygotic (DZ)) aged ≥ 65 years drawn from the Older Australian Twins Study. Dietary data were obtained using a validated food frequency questionnaire and depressive symptoms were measured using the 15-item short form Geriatric Depression Scale. The contribution of genetic and environmental influences on fruit and vegetable intake were estimated by comparing MZ and DZ twin intakes using structural equation modelling. A tri-variate twin model was used to estimate the genetic and environmental correlation between total fruit and vegetable intakes and depression. Results: In this study, vegetable intake was moderately influenced by genetics (0.39 95%CI 0.22, 0.54). Heritability was highest for brassica vegetables (0.40 95%CI 0.24, 0.54). Overall fruit intake was not significantly heritable. No significant genetic correlations were detected between fruit and vegetable intake and depressive symptoms. Conclusions: Vegetable consumption, particularly bitter tasting brassica vegetables, was significantly influenced by genetics, although environmental influences were also apparent. Consumption of fruit was only influenced by the environment, with no genetic influence detected, suggesting strategies targeting the food environment may be particularly effective for encouraging fruit consumption