Strange meson spectroscopy in K[omega] and K[phi] at 11 GeV/c and Cherenkov ring imaging at SLD

Abstract

This thesis consists of two independent parts; development of Cherenkov Ring Imaging Detector (CRID) system and analysis of high-statistics data of strange meson reactions from the LASS spectrometer. Part 1: The CRID system is devoted to charged particle identification in the SLAC Large Detector (SLD) to study e[sup +]e[sup [minus]] collisions at [radical]s = m[sub Z[sup 0]]. By measuring the angles of emission of the Cherenkov photons inside liquid and gaseous radiators, [pi]/K/p separation will be achieved up to [approximately]30 GeV/c. The signals from CRID are read in three coordinates, one of which is measured by charge-division technique. To obtain a [approximately]1% spatial resolution in the charge-division, low-noise CRID preamplifier prototypes were developed and tested resulting in <1000 electrons noise for an average photoelectron signal with 2 [times] 10[sup 5] gain. To help ensure the long-term stability of CRID operation at high efficiency, a comprehensive monitoring and control system was developed. Part 2: Results from the partial wave analysis of strange meson final states in the reactions K[sup [minus]]p [yields] K[sup [minus]][omega]p and K[sup [minus]]p [yields] [bar K][sup 0][phi]n are presented. The analyses are based on data from a 4.1 event/nb exposure of the LASS spectrometer in K[sup [minus]]p interactionsmore » at 11 GeV/c. The data sample of K[sup [minus]][omega]p final state contains [approximately]10[sup 5] events. From the partial wave analysis, resonance structures of J[sup P] = 2[sup [minus]], 3[sup [minus]] and 2[sup +] amplitudes are observed in the K[omega] system. The analysis of 2[sup [minus]] amplitudes provides an evidence for two strange meson states in the mass region around 1.75 GeV/c[sup 2]. The appropriate branching fractions are calculated and compared with the SU(3) predictions. The partial wave analysis of [bar K][sup 0][phi] system favors J[sup P] = 1[sup [minus]] and 2[sup +] states in the 1.9--2.0 GeV/c[sup 2] region.« less