arXiv subjects

P. Fernandez de Cordoba

Publications and source records attributed to P. Fernandez de Cordoba.

40 records · Page 3Linked to original sources

arXiv2004

Nodal solitons and the nonlinear breaking of discrete symmetry

We present a new type of soliton solutions in nonlinear photonic systems with discrete point-symmetry. These solitons have their origin in a novel mechanism of breaking of discrete symmetry by the presence of nonlinearities. These so-called nodal solitons are characterized by nodal lines determined by the discrete symmetry of the system. Our physical realization of such a system is a 2D nonlinear photonic crystal fiber owning C6v symmetry.

nlin.PS↗

arXiv1997

Delta excitation in K^+-nucleus collisions

We present calculations for Δexcitation in the (K^+,K^+) reaction in nuclei. The background from quasielastic K^+ scattering in the Δregion is also evaluated and shown to be quite small in some kinematical regions, so as to allow for a clean identification of the Δexcitation strength. Nuclear effects tied to the Δrenormalization in the nucleus are considered and the reaction is shown to provide new elements to enrich our knowledge of the Δproperties in a nuclear medium.

nucl-th↗

arXiv1996

The Imaginary Part of Nucleon Self-energy in hot nuclear matter

A semiphenomenological approach to the nucleon self-energy in nuclear matter at finite temperatures is followed. It combines elements of Thermo Field Dynamics for the treatment of finite temperature with a model for the self-energy, which evaluates the second order diagrams taking the needed dynamics of the NN interaction from experiment. The approach proved to be accurate at zero temperature to reproduce Im(Sigma) and other properties of nucleons in matter. In the present case we apply it to determine Im(Sigma) at finite temperatures. An effective NN cross section is deduced which can be easily used in analyses of heavy ion reactions.

nucl-th↗

arXiv1996

Coherent pion production in neutrino nucleus collision in the 1 GeV region

We calculate cross sections for coherent pion production in nuclei induced by neutrinos and antineutrinos of the electron and muon type. The analogies and differences between this process and the related ones of coherent pion production induced by photons, or the (p,n) and $(^3 He, t)$ reactions are discussed. The process is one of the several ones occurring for intermediate energy neutrinos, to be considered when detecting atmospheric neutrinos. For this purpose the results shown here can be easily extrapolated to other energies and other nuclei.

nucl-th↗