Engineering topics
Tolos, L
Publications and source records attributed to Tolos, L.
Open-charm mesons in nuclear matter at finite temperature beyond the zero-range approximation
The properties of open charm mesons, D, D, D{sub s}, and D{sub s} in nuclear matter at finite temperature are studied within a self-consistent coupled-channel approach. The interaction of the low-lying pseudoscalar mesons with the ground-state baryons in the charm sector is derived from a t-channel vector-exchange model. The in-medium scattering amplitudes are obtained by solving the Lippmann-Schwinger equation at finite temperature including Pauli blocking effects, baryon dressing, as well as D, D, D{sub s}, and D{sub s} self-energies taking their mutual influence into account. We find that the in-medium properties of the D meson are affected by the D{sub s}-meson self-energy through the intermediate D{sub s}Y loops coupled to DN states. Similarly, dressing the D meson in the DY loops has an influence over the properties of the D{sub s} meson.
Analyticity constraints on the in-medium spectrum of mesons
Analyticity constraints in the form of energy weighted sum rules for the spectral function of mesons are derived, both in cold nuclear matter and at finite temperature, by matching the Dyson propagator with its spectral Lehmann representation at low and high energies. We illustrate our results by calculating the sum rules for specific models of the kaon and pion self-energy in a nuclear medium. We find satisfactory results from the lower energy weight sum rules, which reflect the contributions from the different quasi-particle and collective modes of the meson spectral function, and show examples of the sensitivity of the sum rules to model approximations. Finally, we discuss applications in asymmetric nuclear matter and in the study of the spectral properties of vector mesons.
Spectral properties of mesons in hot and dense matter from energy weighted sum rules
Energy weighted sum rules for the spectral function of mesons are derived, both in cold nuclear matter and at finite temperature, by matching the Dyson propagator with its spectral Lehmann representation at low and high energies. We illustrate our results by calculating the sum rules for specific models of the kaon and pion self-energy in a nuclear medium. We find satisfactory results from the lower energy weight sum rules, which reflect the contributions from the different quasi-particle and collective modes of the meson spectral function, and show examples of the sensitivity of the sum rules to model approximations. Finally, we discuss applications in asymmetric nuclear matter and in the study of the spectral properties of vector mesons.
Exotic dynamically generated baryons with C = -1
We follow a model based on the SU(8) symmetry for the interaction of mesons with baryons. The model treats on an equal footing the pseudo-scalars and the vector mesons, as required by heavy quark symmetry. The T-matrix calculated within an unitary scheme in coupled channels has poles which are interpreted as baryonic resonances.