in this work we use density functional theory based on the ultra-soft pseudo-potential to calculate thestructural, mechanical and thermal properties of narrow single walled bn, aln and gan nanotubes.the electron-electron interactions were expressed within the local density approximation (lda). wehave also obtained the phonon dispersion and elastic constants of these nanotubes using the densityf...

Abstract. The charged kaon decay channel K l3γ allows for studies of direct CP violation, possibly due to non-standard mechanisms, with the help of T -odd correlation variables. In order to be able to extract a CP -violating signal from experiment, it is necessary to understand all possible Standard Model phases that also produce T -odd asymmetries. We complement earlier studies by considering ...

Lepage and Mackenzie have shown that tadpole renormalization and systematic improvement of lattice perturbation theory can lead to much improved numerical results in lattice gauge theory. It is shown that lattice perturbation theory using the Cayley parametrization of unitary matrices gives a simple analytical approach to tadpole renormalization, and that the Cayley parametrization gives lattic...

Cluster Perturbation Theory (CPT) is a simple approximation scheme that applies to lattice models with local interactions, like the Hubbard model, or models where the local interaction is predominant. It proceeds by tiling the lattice into identical, finite-size clusters, solving these clusters exactly and treating the inter-cluster hopping terms at first order in strong-coupling perturbation t...

I consider some selected topics in chiral perturbation theory (CHPT) as probed at colliders such as DAΦNE. Emphasis is put on processes involving pions in the isospin zero S-wave which require multi-loop calculations. These include the scalar form factor of the pion, two–photon fusion into pion pairs and Kl4–decays. The physics of the chiral anomaly is briefly touched upon INVITED LECTURE SUMME...