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Dynamic manipulation of Bose-Einstein condensates with a spatial light modulator

Physical Review A - Atomic, Molecular, and Optical Physics 73:3 (2006)

Authors:

V Boyer, RM Godun, G Smirne, D Cassettari, CM Chandrashekar, AB Deb, ZJ Laczik, CJ Foot

Abstract:

We manipulate a Bose-Einstein condensate using the optical trap created by the diffraction of a laser beam on a fast ferroelectric liquid crystal spatial light modulator. The modulator acts as a phase grating which can generate arbitrary diffraction patterns and be rapidly reconfigured at rates up to 1 kHz to create smooth, time-varying optical potentials. The flexibility of the device is demonstrated with our experimental results for splitting a Bose-Einstein condensate and independently transporting the separate parts of the atomic cloud. 漏 2006 The American Physical Society.

Tunnelling dynamics of a Bose-Einstein condensate in a four-well loop-shaped system

Physical Review A - Atomic, Molecular, and Optical Physics 73:3 (2006)

Authors:

S De Liberato, CJ Foot

Abstract:

We investigated the tunnelling dynamics of a zero-temperature Bose-Einstein condensate in configuration of four potential wells arranged in a loop. We found three interesting dynamic regimes: (a) flows of matter with small amplitude, (b) steady flow, and (c) forced flow of matter for large amplitudes. The regime of quantum self-confinement has been studied and a new variant of it has been found for this system. 漏 2006 The American Physical Society.

Collisional relaxation of Feshbach molecules and three-body recombination in 87Rb Bose-Einstein condensates

(2006)

Authors:

G Smirne, RM Godun, D Cassettari, V Boyer, CJ Foot, T Volz, N Syassen, S D眉rr, G Rempe, MD Lee, K Goral, T Koehler

Experimental limits on weak annihilation contributions to b鈫抲l谓 decays

Physical Review Letters 96:12 (2006)

Authors:

JL Rosner, NE Adam, JP Alexander, K Berkelman, DG Cassel, JE Duboscq, KM Ecklund, R Ehrlich, L Fields, L Gibbons, R Gray, SW Gray, DL Hartill, BK Heltsley, D Hertz, CD Jones, J Kandaswamy, DL Kreinick, VE Kuznetsov, H Mahlke-Kr眉ger, TO Meyer, PUE Onyisi, JR Patterson, D Peterson, EA Phillips, J Pivarski, D Riley, A Ryd, AJ Sadoff, H Schwarthoff, X Shi, S Stroiney, WM Sun, T Wilksen, M Weinberger, SB Athar, P Avery, L Breva-Newell, R Patel, V Potlia, H Stoeck, J Yelton, P Rubin, C Cawlfield, BI Eisenstein, I Karliner, D Kim, N Lowrey, P Naik, C Sedlack, M Selen, JJ Thaler, EJ White, J Wiss, MR Shepherd, DM Asner, KW Edwards, D Besson, TK Pedlar, D Cronin-Hennessy, KY Gao, DT Gong, J Hietala, Y Kubota, T Klein, BW Lang, R Poling, AW Scott, A Smith, S Dobbs, Z Metreveli, KK Seth, A Tomaradze, P Zweber, J Ernst, K Arms, H Severini, SA Dytman, W Love, S Mehrabyan, JA Mueller, V Savinov, Z Li, A Lopez, H Mendez, J Ramirez, GS Huang, DH Miller, V Pavlunin, B Sanghi, IPJ Shipsey, GS Adams, M Anderson, JP Cummings, I Danko, J Napolitano, Q He, H Muramatsu, CS Park, EH Thorndike

Abstract:

We present the first experimental limits on high-q2 contributions to charmless semileptonic B decays of the form expected from the weak annihilation (WA) decay mechanism. Such contributions could bias determinations of |Vub| from inclusive measurements of B鈫扻ul谓. Using a wide range of models based on available theoretical input we set a limit of 螕WA/螕b鈫抲<7.4% (90% confidence level) on the WA fraction, and assess the impact on previous inclusive determinations of |Vub|. 漏 2006 The American Physical Society.

Simulation of heavily irradiated silicon pixel detectors

Proceedings of the International Symposium on Detector Development for Particle, Astroparticle and Synchrotron Radiation Experiments (SNIC 2006) SLAC National Accelerator Laboratory (2006) 0014

Authors:

M Swartz, V Chiochia, Y Allkofer, C Amsler, Daniela Bortoletto, L Cremaldi, S Cucciarelli, A Dorokhov, C Hoermann, D Kim, M Konecki, D Kotlinski, K Prokofiev, C Regenfus, T Rohe, DA Sanders, S Son, T Speer

Abstract:

We show that doubly peaked electric fields are necessary to describe grazing-angle charge collection measurements of irradiated silicon pixel sensors. A model of irradiated silicon based upon two defect levels with opposite charge states and the trapping of charge carriers can be tuned to produce a good description of the measured charge collection profiles in the fluence range from 0.5x10^{14} Neq/cm^2 to 5.9x10^{14} Neq/cm^2. The model correctly predicts the variation in the profiles as the temperature is changed from -10C to -25C. The measured charge collection profiles are inconsistent with the linearly-varying electric fields predicted by the usual description based upon a uniform effective doping density. This observation calls into question the practice of using effective doping densities to characterize irradiated silicon. The model is now being used to calibrate pixel hit reconstruction algorithms for CMS.