43798294
A Silicon Vertex Detector for CDF
The major reason for building a vertex detector for CDF is the tagging of decay vertices of particles with lifetime in the 10-13/10-12 sec. range. This is a complementary approach to heavy flavour physics with respect to missing Et and large Pt leptons. The method can be best applied to tag hadronic decays of heavy flavours, which have the largest branching ratios, but have eluded any specific tagging until now. It also works, although with somewhat reduced efficiency, in events with a semileptonic decay. All in all it promises to be a powerful tool in the search of rather elusive processes like Higgs, top, or fourth generation quark production [1]. The additional information provided by the vertex detector will also improve significantly the resolution of the CDF central tracking system [2].
116537730
Measurement of the top quark mass using the MINUIT fitter in dilepton events at CDF
53067347
New-generation large-area muon scintillation counters with wavelength shifter fiber readout for CDF II
New scintillation counters have been designed and constructed for upgrading the CDF detector at Fermilab Tevatron. A novel light collection technique using wavelength shifting fibers, together with a high-quality polystyrene-based scintillator UPS 923A, has resulted in compact counters with good and stable light collection efficiency over their lengths extending up to 320 cm. The design, construction, and performance of the counters are presented. Properties of the fibers and the scintillator, such as light output, light attenuation, decay time, and long-term stability, are investigated. It is found that the polystyrene-based scintillator, unlike the polyvinyltoluene-based one, has properties more adequate for long-term experiments.
55580299
Constraining spacetime torsion with LAGEOS
We compute the corrections to the orbital Lense-Thirring effect (or frame-dragging) in the presence of spacetime torsion. We analyze the motion of a test body in the gravitational field of a rotating axisymmetric massive body, using the parametrized framework of Mao, Tegmark, Guth and Cabi. In the cases of autoparallel and extremal trajectories, we derive the specific approximate expression of the corresponding system of ordinary differential equations, which are then solved with methods of Celestial Mechanics. We calculate the secular variations of the longitudes of the node and of the pericenter. We also show how the LAser GEOdynamics Satellites (LAGEOS) can be used to constrain torsion parameters. We report the experimental constraints obtained using both the nodes and perigee measurements of the orbital Lense-Thirring effect. This makes LAGEOS and Gravity Probe B complementary frame-dragging and torsion experiments, since they constrain three different combinations of torsion parameters.