a Measurement of the Average Lifetime of B Hadrons Using Vertex Reconstruction.
Abstract
A measurement of the average lifetime of B hadrons produced in e^+ e^ - interaction at 35 GeV center of mass energy is presented. The data was taken with the TASSO detector, including a high-precision vertex detector, at the PETRA storage ring. The method attempts to locate the decay point of the B hadrons in the data by reconstructing an appropriate vertex. The flight distance from the event vertex, measured by the beam spot, to the reconstructed vertex is measured using the sphericity axis as a measurement of the B flight direction. The statistical separation of B hadrons from background is accomplished by the vertex selection process and no independent 'B-enrichment' is needed. The B lifetime is extracted from the distribution of flight distances by comparison with distributions found in simulated events. The result of this method is tau_{B} = 1.30 +/- 0.10 +/- 0.28 ps, where the first error is statistical and the second systematic.
- Publication:
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Ph.D. Thesis
- Pub Date:
- 1989
- Bibcode:
- 1989PhDT........70M
- Keywords:
-
- Physics: Elementary Particles and High Energy