Charmed particle production and decay in a high energy photoproduction experiment

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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--$95~\%$ is achieved for tracks with momenta above 2~GeV for a ghost rate of $13~\%$

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 $96.3~\%$ is achieved for a ghost rate of 8.1~\%. In addition, the expected performance of the algorithm during the 2007 pilot run is discussed

Two body decays of the bb-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

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

Beam Spot Position Measurement at the LEP Collider

A precise knowledge of the beam spot position is required for many physics topics at LEP2. The movement of the beam spot is studied at LEP1 using beam orbit monitors close to the interaction points and compared with measurements from tracks produced in e+e- collisions. The beam orbit monitors are found to follow the beam spot position well, particularly when corrected for movements of nearby quadrupole magnets. Data from the LEP high energy run of November 1995 are also analysed, and projections made for the prospects at LEP2

Test-beam and laboratory characterisation of the TORCH prototype detector

The TORCH time-of-flight (TOF) detector is being developed to provide particle identification up to a momentum of 10 GeV/c over a flight distance of 10 m. It has a DIRC-like construction with View the MathML source10mm thick synthetic amorphous fused-silica plates as a Cherenkov radiator. Photons propagate by total internal reflection to the plate periphery where they are focused onto an array of customised position-sensitive micro-channel plate (MCP) detectors. The goal is to achieve a 15 ps time-of-flight resolution per incident particle by combining arrival times from multiple photons. The MCPs have pixels of effective size 0.4 mm×6.6 mm2 in the vertical and horizontal directions, respectively, by incorporating a novel charge-sharing technique to improve the spatial resolution to better than the pitch of the readout anodes. Prototype photon detectors and readout electronics have been tested and calibrated in the laboratory. Preliminary results from testbeam measurements of a prototype TORCH detector are also presented

Heavy Quark Spectroscopy and Matrix Elements: A Lattice Study using the Static Approximation

We present results of a lattice analysis of the $B$ parameter, $B_B$, the decay constant $f_B$, and several mass splittings using the static approximation. Results were obtained for 60 quenched gauge configurations computed at $\beta=6.2$ on a lattice size of $24^3\times48$. Light quark propagators were calculated using the $O(a)$-improved Sheikholeslami-Wohlert action. We find \Bbstat(m_b) = 0.69\er{3}{4} {\rm(stat)}\er{2}{1} {\rm(syst)}, corresponding to \Bbstat = 1.02\er{5}{6}\er{3}{2}, and \fbstat = 266\err{18}{20}\err{28}{27} \mev, f_{B_s}^2 B_{B_s}/f_B^2 B_B = 1.34\er{9}{8}\er{5}{3}, where a variational fitting technique was used to extract \fbstat. For the mass splittings we obtain M_{B_s}-M_{B_d} = 87\err{15}{12}\err{6}{12} \mev, M_{\Lambda_b}-M_{B_d} = 420\errr{100}{90}\err{30}{30} \mev and M_{B^*}^2-M_B^2 = 0.281\err{15}{16}\err{40}{37} \gev^2. We compare different smearing techniques intended to improve the signal/noise ratio. From a detailed assessment of systematic effects we conclude that the main systematic uncertainties are associated with the renormalisation constants relating a lattice matrix element to its continuum counterpart. The dependence of our findings on lattice artefacts is to be investigated in the future.Comment: 40 pages, uuencoded compressed tar file, containing one LaTeX file and 14 postscript files (to be included with epsf). Minor change in the value of the B parameter. Contains corrected value for the B*-B mass splitting. Version accepted for publication in Phys. Rev.

An overview of historical and contemporary concrete shells, their construction and factors in their general disappearance

Only through understanding why concrete shells’ loss in popularity over the course of modern history can designers be equipped with the skills to create and apply this type of construction. Through modifications to design processes, construction stages, material understanding and relevant formwork improvements will architects and designers be able to meet the demands of the 21st century and beyond. To understand why concrete shells are no longer commonly built is to understand its construction process. An amorphous material, the fundamental relationship between formwork and the resultant concrete shell needs to be raised, appreciated, understood and analyzed for a holistic understanding of concrete shells. Through understanding this, issues and factors affecting concrete shells can be tackled and designed out in reviving this type of structures because they can be efficient in structural performance, economical in cost and provide high aesthetic value. This paper discusses concrete shells as an architectural solution by asking the question to what constituted their popularity and factors that led to their demise in the modern age of technological advancement, construction process and environmental concerns. This paper presents a cultural perspective and an overview of seminal, historical and contemporary concrete shells so as to bring about a renaissance of such structures in our built environment once again because of all the benefits it can offer.</p

Long-Baseline Study of the Leading Neutrino Oscillation at a Neutrino Factory

Within the framework of three-flavor neutrino oscillations, we consider the physics potential of \nu_e --> \nu_\mu appearance and \nu_\mu --> \nu_\mu survival measurements at a neutrino factory for a leading oscillation scale \delta m^2 ~ 3.5 \times 10^{-3} eV^2. Event rates are evaluated versus baseline and stored muon energy, and optimal values discussed. Over a sizeable region of oscillation parameter space, matter effects would enable the sign of \delta m^2 to be determined from a comparison of \nu_e --> \nu_\mu with \bar\nu_e --> \bar\nu_\mu event rates and energy distributions. It is important, therefore, that both positive and negative muons can be stored in the ring. Measurements of the \nu_\mu --> \nu_\mu survival spectrum could determine the magnitude of \delta m^2 and the leading oscillation amplitude with a precision of O(1%--2%).Comment: 33 pages, single-spaced Revtex, uses epsf.sty, 14 postscript figures. Added references, expanded conclusions, improved figs. 13 and 14. Version to be published in Phys. Rev.