Measurement of top quark polarization in top-antitop events from proton-proton collisions at √s = 7 TeV using the ATLAS detector
Physical Review Letters 111:23 (2013)
Abstract:
This Letter presents measurements of the polarization of the top quark in top-antitop quark pair events, using 4:7 fb–1of proton-proton collision data recorded with the ATLAS detector at the Large Hadron Collider at √s = 7 TeV. Final states containing one or two isolated leptons (electrons or muons) and jets are considered. Two measurements of αℓP, the product of the leptonic spin-analyzing power and the top quark polarization, are performed assuming that the polarization is introduced by either a CP conserving or a maximally CP violating production process. The measurements obtained, αℓPCPC=–0.035 ± 0.014(stat) ± 0:037(syst) and αℓPCPV= 0.020 ± 0:016(stat)+0.013–0.017(syst), are in good agreement with the standard model prediction of negligible top quark polarization.Longitudinal profile monitor using smith-purcell radiation: Recent results from the E-203 Collaboration
IBIC 2013: Proceedings of the 2nd International Beam Instrumentation Conference (2013) 464-466
Abstract:
We report on recent measurements made at FACET by the E-203 collaboration to test a longitudinal bunch profile monitor based on Coherent Smith-Purcell radiation. The capacity of this monitor to resolve sub-picosecond bunches will be shown as well as a comparison of profile reconstructed for different data sets. We also present recent electromagnetic simulations of the interactions between the beam and the grating as well as the expected resolution of such monitor with a "notch collimator".Presentation of the smith-purcell experiment at SOLEIL
IBIC 2013: Proceedings of the 2nd International Beam Instrumentation Conference (2013) 460-463
Abstract:
The potential of Coherent Smith-Purcell radiation as a longitudinal bunch profile monitor has already been demonstrated and has recently been extended to the sub-picosecond range. As a critical step toward the construction of a single shot bunch profile monitor using Coherent Smith-Purcell radiation it is important to measure very accurately the distribution of such radiation. Optimum background suppression techniques need to be found and relatively cheap detectors suitable for the far infra-red need to be qualified. To perform these tasks a test stand has been installed at the end of the linac of the synchrotron SOLEIL. This test stand and the first results from its commissioning will be presented here.Some properties of coherent smith-purcell radiation from electron bunches and gratings of finite dimensions
International Conference on Infrared, Millimeter, and Terahertz Waves, IRMMW-THz (2013)
Abstract:
There is a strong interest in the development of single shot diagnostics of fs relativistic electron bunches within a number of research areas including compact particle accelerators and THz and X-ray sources of radiation. The goal of this work is to investigate some properties of coherent Smith-Purcell radiation and to use it for the reconstruction of the longitudinal profile of a fs-long electron bunch. © 2013 IEEE.Multicenter retrospective comparative study of laparoscopically assisted and conventional anorectoplasty for male infants with rectoprostatic urethral fistula.
Journal of pediatric surgery 48:12 (2013) 2383-2388