28,304 research outputs found
Chiral approach to antikaon s- and p-wave interactions in dense nuclear matter
The properties of the antikaons in nuclear matter are investigated from a
chiral unitary approach which incorporates the s- and p-waves of the interaction. To obtain the in-medium meson-baryon amplitudes we include,
in a self-consistent way, Pauli blocking effects, meson self-energies corrected
by nuclear short-range correlations and baryon binding potentials. We pay
special attention to investigating the validity of the on-shell factorization,
showing that it cannot be applied in the evaluation of the in-medium
corrections to the p-wave amplitudes. In nuclear matter at saturation energy,
the and develop an attractive potential of about -30 MeV,
while the pole remains at the free space value although its width
gets sensibly increased to about 80 MeV. The antikaon also develops a moderate
attraction that does not support the existence of very deep and narrow bound
states, confirming the findings of previous self-consistent calculations.Comment: 29 pages, 12 figures, published in Physical Review
Charm at FAIR
Charmed mesons in hot and dense matter are studied within a self-consistent
coupled-channel approach for the experimental conditions of density and
temperature expected at the CBM experiment at FAIR/GSI. The meson spectral
function broadens with increasing density with an extended tail towards lower
energies due to and
excitations. The in-medium meson mass increases with density. We also
discuss the consequences for the renormalized properties in nuclear matter of
the charm scalar and D(2400), and the predicted hidden charm
X(3700) resonances at FAIR energies.Comment: 6 pages, 3 figures, to appear in the proceedings of ExcitedQCD 09,
Zakopane, Poland, 8-14 February 200
Avaliação do potencial da madeira de Eucalyptus urograndis para a produção de etanol celulósico a partir do pré-tratamento por explosão a vapor e hidrólise enzimática.
Resumo
Avaliação do potencial da madeira de Eucalyptus urograndis para a produção de etanol celulósico a partir do pré-tratamento por explosão vapor e hidrólise enzimática.
Resumo
meson in dense matter
We study the properties of mesons in nuclear matter using a
unitary approach in coupled channels within the framework of the local hidden
gauge formalism and incorporating the decay channel in matter. The
in-medium interaction accounts for Pauli blocking effects and
incorporates the self-energy in a self-consistent manner. We also
obtain the (off-shell) spectral function and analyze its behaviour
at finite density and momentum. At normal nuclear matter density, the meson feels a moderately attractive potential while the width
becomes five times larger than in free space. We estimate the transparency
ratio of the reaction, which we propose as
a feasible scenario at present facilities to detect the changes of the
properties of the meson in the nuclear medium.Comment: 26 pages, 9 figures, one new section added, version published in
Phys. ReV. C, http://link.aps.org/doi/10.1103/PhysRevC.82.04521
Investigation of -dependent dynamical heterogeneity in a colloidal gel by x-ray photon correlation spectroscopy
We use time-resolved X-Photon Correlation Spectroscopy to investigate the
slow dynamics of colloidal gels made of moderately attractive carbon black
particles. We show that the slow dynamics is temporally heterogeneous and
quantify its fluctuations by measuring the variance of the instantaneous
intensity correlation function. The amplitude of dynamical fluctuations has a
non-monotonic dependence on scattering vector , in stark contrast with
recent experiments on strongly attractive colloidal gels [Duri and Cipelletti,
\textit{Europhys. Lett.} \textbf{76}, 972 (2006)]. We propose a simple scaling
argument for the -dependence of fluctuations in glassy systems that
rationalizes these findings.Comment: Final version published in PR
Pré-otimização do pré-tratamento por explosão a vapor de Eucalyptus urograndis visando maior susceptibilidade na hidrólise enzimática.
21-SBQSul. Poster
Shape evolution and shape coexistence in Pt isotopes: comparing interacting boson model configuration mixing and Gogny mean-field energy surfaces
The evolution of the total energy surface and the nuclear shape in the
isotopic chain Pt are studied in the framework of the interacting
boson model, including configuration mixing. The results are compared with a
self-consistent Hartree-Fock-Bogoliubov calculation using the Gogny-D1S
interaction and a good agreement between both approaches shows up. The
evolution of the deformation parameters points towards the presence of two
different coexisting configurations in the region 176 A 186.Comment: Submitted to PR
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