Mini séminaires 5/5

Thursday 21 Apr 2011, 10:30 → 12:00 Europe/Paris

10:30 → 11:00 Dark matter annihilation in the Galaxy: gamma-rays from substructures and dwarf spheroidal galaxies

The nature of dark matter still evades us. In this talk, I will focus on the gamma-ray flux from dark matter annihilation, which has been tagged as a promising channel for indirect detection. I will first present CLUMPY, a new public code we developed to compute the gamma-ray flux from any dark matter distribution and instrumental resolution. In the second part of the talk, I will present the recent study we conducted on the detectability of such a signal in the classical dwarf spheroidal galaxies of the Milky Way, based on an MCMC analysis of the kinematical data. I will conclude by providing a new ranking in terms of detectability of these objects for present and future gamma-ray observatories.

Speaker: Céline COMBET (Leicester)

11:00 → 11:30 La recherche pour la radiothérapie

Ces dernières années, de nombreuses innovations ont permis d'améliorer les traitements du cancer par radiothérapie. Les technologies utilisées en radiothérapie et en imagerie connaissent une évolution importante qui modifie l’approche thérapeutique et la stratégie de traitement. En contrepartie, elles nécessitent une évaluation précise du dépôt de dose. Les simulations Monte Carlo sont des outils incontournables pour calculer les dépôts de dose avec une précision suffisante. Des dispositifs expérimentaux sont également en développement pour contrôler les dépôts de dose pendant le traitement.

Speaker: Thibault Frisson

11:30 → 12:00 Mapping the nucleon resonance spectrum – new measurement of beam asymmetry in pion photoproduction from the neutron using CLAS at Jefferson Lab

The nucleon resonance spectrum holds important information on the dynamics and interactions of its constituents. It presents a veritable chal- lenge to the theoretical models of nucleon structure – from emerging Lat- tice QCD predictions to phenomenological approaches. Although various descriptions of the nucleon predict very different features for the excitation spectra, experimental information is still too poor to differentiate between the models. A new generation of meson-photoproduction experiments us- ing polarised targets is underway to complete the set of measurements required for a model-independent mapping of the nucleon spectrum. I will present a recent measurement of beam asymmetry in pion photopro- duction from the neutron, made using the CLAS spectrometer at Jefferson Laboratory, USA.

Speaker: Daria Sokhan