Geneva University
École de physique - Département de physique nucléaire et corpusculaire
24, quai Ernest-Ansermet 1211 GENÈVE 4 Tél: (022) 379 62 73 - Fax: (022) 379 69 92
Lundi 6 avril 2009
PARTICLE PHYSICS SEMINAR
àt 17:00 – Auditoire Stückelberg
Hospital superbugs, nanomechanics and statistical physics
Prof. Dr G. Aeppli / University College London
The alarming growth of the antibiotic-resistant superbug, methicillin-resistant Staphylococcus aureus (MRSA) is driving the development of new technologies to investigate antibiotics and their modes of action. We report silicon cantilever based studies of self-assembled monolayers of mucopeptides which model drug-sensitive and resistant bacterial walls. The underlying concepts needed to understand the measurements will simplify the design of cantilevers and coatings for biosensing and could even impact our understanding of drug action on bacteria themselves.
(Une verrée en compagnie du conférencier sera offerte après le colloque.)
Organizer : Prof. Markus Büttiker
Wednesday 8 April 2009
PARTICLE PHYSICS SEMINAR
àt 17:00 – Auditoire Stückelberg
The OSQAR Experiments at CERN to probe QED & Astroparticle Physics from the Photon Interaction with a Magnetic Field
Dr. Pierre PUGNAT / CNRS - GHMFL (Grenoble High Magnetic Field Laboratory) & CERN
A collaboration between eight European Institutes and CERN is working on a new "2-in-1", laser-based Particle Physics experiments for Optical Search of QED vacuum magnetic birefringence, Axions and photon Regeneration (OSQAR). Since its prediction in 1936 by Euler, Heisenberg and Weisskopf in the earlier development of the Quantum Electrodynamic (QED), the Vacuum Magnetic Birefringence (VMB) is still a challenge for optical metrology. Contributions to the VMB could also arise from new light scalar/pseudo-scalar particles like axions that couple to photons and this would manifest itself as a sizeable deviation from the pure QED prediction. On one side the interest in axion, providing the most plausible solution to the so-called strong-CP problem, lies beyond Particle Physics and overlaps with Cosmology since such particle is also considered as a serious dark matter candidate. On the other side, the domain of Physics that will be investigated is guaranteed by the QED, which aimed to be tested down to the 10-22 level by measuring the relative difference of the vacuum refractive indices in a 9.5 T field. The measurement for the first time of this "vacuum anomaly" of the refraction index is in the same line than the measurement of the anomalous magnetic moment of the muon performed in the early years of CERN by G. Charpak et al. (1961). By re-using major achievements of the Large Hadron Collider (LHC), like superconducting dipoles and test infrastructure, OSQAR offers a unique opportunity to launch at CERN an innovative research programme in the emerging field of laser-based Particle/Astroparticle Physics. The status of the OSQAR project will be reported together with the theoretical background, first results (published in Phys. Rev. D 78, 092003, 2008) as well as short and long term perspectives."
Information :
http://dpnc.unige.ch/seminaire/annonce.html
Organizer : J.-S. Graulich