3,420 research outputs found
Charmed particle production and decay in a high energy photoproduction experiment
Imperial Users onl
Standalone Track Reconstruction in the T-stations
An algorithm for fast and efficient tracking in the T-stations is describedtogether with its performance in the DC06 data challenge. An efficiency of94-- is achieved for tracks with momenta above 2~GeV for a ghost rate of
Updated Performance of the T-Seeding
Improvements to the performance of the track seeding since the start of the DC '06 data challenge are described. For tracks above 2~GeV an efficiency of is achieved for a ghost rate of 8.1~\%. In addition, the expected performance of the algorithm during the 2007 pilot run is discussed
TORCH: A Cherenkov Based Time-of-Flight Detector
TORCH is a novel high-precision time-of-flight detector suitable for large area applications and
covering the momentum range up to 10 GeV/c. The concept uses Cherenkov photons produced
in a fused silica radiator which are propagated to focussing optics coupled to fast photodetectors.
For this purpose, custom MCP-PMTs are being produced in collaboration with industrial partners.
The development is divided into three phases. Phase 1 addresses the lifetime requirements for
TORCH, Phase 2 will customize the MCP-PMT granularity and Phase 3 will deliver prototypes
that meet the TORCH requirements. Phase 1 devices have been successfully delivered and initial
tests show stable gain performance for integrated anode current >5 C/cm2
and a single photon
time resolution of †30 ps. Initial simulations indicate the single photon timing resolution of the
TORCH detector will be âŒ70 ps
Analysis and correction of the magnetic field effects in the Hybrid Photo-Detectors of the RICH2 Ring Imaging Cherenkov detector of LHCb
The Ring Imaging Cherenkov detectors of the LHCb experiment at the Large
Hadron Collider at CERN are equipped with Hybrid Photo-Detectors. These vacuum
photo-detectors are affected by the stray magnetic field of the LHCb magnet,
which degrades their imaging properties. This effect increases the error on the
Cherenkov angle measurement and would reduce the particle identification
capabilities of LHCb. A system has been developed for the RICH2 Ring Imaging
Cherenkov detector to perform a detailed characterisation of the magnetic
distortion effects. It is described, along with the methods implemented to
correct for these effects, restoring the optimal resolution.Comment: 16 pages, 11 figure
Two body decays of the -quark: Applications to direct CP violation, searches for electro-weak penguins and new physics
A systematic experimental search for two-body hadronic decays of the b-quark
of the type b to quark + meson is proposed. These reactions have a well defined
experimental signature and they should be theoretically cleaner compared to
exclusive decays. Many modes have appreciable branching ratios and partial rate
asymmetries may also be quite large (about 8-50%) in several of them. In a few
cases electroweak penguins appear to be dominant and may be measurable. CP
violating triple correlation asymmetries provide a clean test of the Standard
Model.Comment: 12 pages 1 figure 1 tabl
A Comment on the Experimental Determination of .
We propose a method to extract the ratio from a
measurement of for the meson. This method is
experimentally more sensitive than the conventional method for large values of
but depends on the accuracy of parton level calculations.Comment: 6 pages, LATEX forma
Averaging lifetimes for B hadron species
The measurement of the lifetimes of the individual B species are of great interest. Many of these measurements are well below the 10 level of precision. However, in order to reach the precision necessary to test the current theoretical predictions, the results from different experiments need to be averaged. Therefore, the relevant systematic uncertainties of each measurement need to be well defined in order to understand the correlations between the results from different experiments. \par In this paper we discuss the dominant sources of systematic errors which lead to correlations between the different measurements. We point out problems connected with the conventional approach of combining lifetime data and discuss methods which overcome these problems
Monochromatic Propagation-Based Phase-Contrast Microscale Computed-Tomography System with a Rotating-Anode Source
We present an experimental setup for monochromatic propagation-based x-ray phase-contrast imaging based on a conventional rotating-copper-anode source, capable of an integrated flux up to 108 photons/s at 8 keV. In our study, the system is characterized in terms of spatial coherence, resolution, contrast sensitivity, and stability. Its quantitativeness is demonstrated by comparing theoretical predictions with experimental data on simple wire phantoms both in planar and computerized-tomography-scan geometries. Application to two biological samples of medical interest shows the potential for bioimaging on the millimeter scale with spatial resolution of the order of 10 \u3bcm and contrast resolution below 1%. All the scans are performed within laboratory-compatible exposure times, from 10 min to a few hours, and trade-offs between scan time and image quality are discussed
TORCH: A Cherenkov Based Time-of-Flight Detector
TORCH is a novel high-precision time-of-flight detector suitable for large area applications and
covering the momentum range up to 10 GeV/c. The concept uses Cherenkov photons produced
in a fused silica radiator which are propagated to focussing optics coupled to fast photodetectors.
For this purpose, custom MCP-PMTs are being produced in collaboration with industrial partners.
The development is divided into three phases. Phase 1 addresses the lifetime requirements for
TORCH, Phase 2 will customize the MCP-PMT granularity and Phase 3 will deliver prototypes
that meet the TORCH requirements. Phase 1 devices have been successfully delivered and initial
tests show stable gain performance for integrated anode current >5 C/cm2
and a single photon
time resolution of †30 ps. Initial simulations indicate the single photon timing resolution of the
TORCH detector will be âŒ70 ps
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