AION/Magis

Abstract:

The aging behavior of wire chambers have been of great interest for many years. Recently a new generation of proportional chambers have been developed including the microstrip gas chamber (MSGC) microgap chamber (MGC) and gaseous electron multiplier (GEM). Aging studies of these detectors are of particular interest to the LHC (Large Hadron Collider) community because the baseline design of the CMS experiment includes MSGCs as part of the tracking system. We have performed an aging study of a GEM detector readout with a MSGC. The GEM is constructed from Kapton and copper, the MSGC is constructed from semiconductive glass and gold. When the detector is operated in argon and dimethyl ether (DME) gas mixture and irradiated with a 6 KeV photon beam, about 220 mC/cm of charge can be accumulated without degradation of the detector performance. This corresponds to about 20 years of operation at the LHC.

Abstract:

We report on the demonstration of Berry’s phase in an atomic state interacting with a laser field. We draw an analogy between this system and that of a spin interacting with a directionally varying magnetic field. This allows us to identify an effective magnetic quantum number for the atom-light system that governs the maximum Berry phase the atomic state can acquire. We realize two systems that have different effective magnetic quantum numbers, and use a recently developed atom interferometer to make measurements of Berry’s phase. © 1999 The American Physical Society.

Abstract:

Since the first observation in 1964, CP violation remains one of the most elusive aspects of the standard model. The CDF collaboration has reported the first evidence of CP violation in the B system using the world's largest sample of B → J/ψKS0 decays. The direct measurement of sin(2β)=0.79+0.41−0.44(combined statistical and systematic error) agrees with the standard model predictions. New data collected from the B-factories and from the upgraded experiments at the Tevatron should allow a more precise measurement of sin 2β in the near future.

Abstract:

We describe the low-energy scattering theory relevant to the description of the Bose-Einstein condensed gases recently produced using evaporative cooling. We examine the validity range of the approximations being used to describe the ultracold interactions in the context of the interaction between caesium atoms at the temperatures produced by evaporation in a magnetic trap. We discuss the prospects for future developments in the field.