44,661 research outputs found
Light meson resonances from unitarized Chiral Perturbation Theory
We report on our recent progress in the generation of resonant behavior in
unitarized meson-meson scattering amplitudes obtained from Chiral Perturbation
Theory. These amplitudes provide simultaneously a remarkable description of the
resonance region up to 1.2 GeV as well as the low energy region, since they
respect the chiral symmetry expansion. By studying the position of the poles in
these amplitudes it is possible to determine the mass and width of the
associated resonances, as well as to get a hint on possible classification
schemes, that could be of interest for the spectroscopy of the scalar sector.Comment: Invited talk to the II International Workshop on Hadron Physics &
Effective Theories of Low Energy QCD. 25-29 September 2002. Coimbra. Portuga
Meson resonances from unitarized meson scattering at one loop in Chiral Perturbation Theory
We show the results for the scattering poles associated to the rho, f0, a0,
K*, sigma and kappa resonances in meson-meson scattering. Our amplitudes are
obtained from the complete one-loop meson-meson scattering amplitudes from
Chiral Perturbation Theory. Once unitarized with the Inverse Amplitude Method,
they describe remarkably well the data simultaneously in the low energy and
resonance regions up to 1.2 GeV, using low energy parameters compatible with
present determinations.Comment: To appear in the proceedings of the 5th International Conference on
``Quark confinement and the hadron spectrum'', held in Gargnano, Garda Lake,
Italy. 10-14th September 2002. 3 page
Unitarization of the complete meson-meson scattering at one loop in Chiral Perturbation Theory
We report on our one-loop calculation of all the two meson scattering
amplitudes within SU(3) Chiral Perturbation Theory, i.e. with pions, kaons and
etas. Once the amplitudes are unitarized with the coupled channel Inverse
Amplitude Method, they satisfy simultaneously the correct low-energy chiral
constraints and unitarity. We obtain a remarkable description of meson-meson
scattering data up to 1.2 GeV including the scattering lengths and seven light
resonances.Comment: To appear in the proceedings of QCD@work: International Workshop on
QCD: Theory and Experiment. Martina Franca (Italy) June 16-20. 200
Complete meson-meson scattering within one loop in Chiral Perturbation Theory: Unitarization and resonances
We review our recent one-loop calculation of all the two meson scattering
amplitudes within SU(3) Chiral Perturbation Theory, i.e. with pions, kaons and
etas. By unitarizing these amplitudes we are able to generate dynamically the
lightest resonances in meson-meson scattering. We thus obtain a remarkable
description of the meson-meson scattering data right from threshold up to 1.2
GeV, in terms of chiral parameters in good agreement with previous
determinations.Comment: 4 pages, To appear in the Proceedings of the IX International
Conference on Hadron Spectroscopy, HADRON2001, IHEP, Protvino, Russia, August
200
Magnetic Field Satellite (Magsat) data processing system specifications
The software specifications for the MAGSAT data processing system (MDPS) are presented. The MDPS is divided functionally into preprocessing of primary input data, data management, chronicle processing, and postprocessing. Data organization and validity, and checks of spacecraft and instrumentation are dicussed. Output products of the MDPS, including various plots and data tapes, are described. Formats for important tapes are presented. Dicussions and mathematical formulations for coordinate transformations and field model coefficients are included
Heat Fluctuations in Brownian Transducers
Heat fluctuation probability distribution function in Brownian transducers
operating between two heat reservoirs is studied. We find, both analytically
and numerically, that the recently proposed Fluctuation Theorem for Heat
Exchange [C. Jarzynski and D. K. Wojcik, Phys. Rev. Lett. 92, 230602 (2004)]
has to be modified when the coupling mechanism between both baths is
considered. We also extend such relation when external work is present. Our
work fixes the domain of applicability of the theorem in more realistic
operating systems.Comment: Comments are welcom
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