Searching for B°s [to] J/ψ with the collider detector at Fermilab

This thesis describes a detailed research for the decay B°s (r) J/ψh, within data taken from p collisions at √s=1.8TeV. Proton anti-proton collisions contain many different physics processes. From these processes many are of lesser interest. The trigger logic specific to selecting a sample of data rich in processes relevant to this particular study is described in detail. The analysis method proceeds as follows. The simulation program used to model acceptances of B+ (r) J/ψK+ and B°s (r) J/ψh samples is described. Within this description theoretical inputs and assumptions made are given in detail. Constraints made on each generated sample are then outlined. From the simulation, the discussion turns to the reconstruction of B+ (r) J/ψK+ and the search for B°s (r) J/ψh within the CDF data. All stages of data selection are discussed. The analysis then turns to acceptance and efficiency factors considered. Specific effort is made to fully describe the photon reconstruction efficiency. Photon reconstruction efficiency is studied in the CDF environment by introducing a data based Monte Carlo program. This detailed simulation is discussed and final photon reconstruction efficiencies are given. Systematic uncertainties are analysed in detail. The generator level simulation is used to provide error propagation for acceptance and efficiency parameterisations introduced. Systematic uncertainties from the analysis of data are also given. The results of the B (r) J/ψK+ reconstruction and the search for B°s (r) J/ψh are given. From an integrated luminosity of 110pb-1, 1178171 J/ψ (r) m+ m- events were collected. 490 ± 23 B+ (r) J/ψK+ events were isolated. From the sample of J/ψ(r) m+m- events a branching ratio limit of B(B°s (r) J/ψh) < 6.3 x 10-3 is set at a 90% confidence limit.

Level dc:type.qualificationlevel

PhD

Grantor dc:publisher.institution

University of Glasgow

Year dc:date.issued

2002

Author dc:creator

• Bell, William Hamish

• QB Astronomy
• QC Physics

Language dc:language

en