University of Connecticut

Events Calendar

PhD Defense

Friday, April 21, 2017
2:00pm – 4:30pm

Storrs Campus
Physics Building, Room P121

Alex Barnes, Experimental Nuclear Physics, University of Connecticut

Development of the Tagger Microscope Analysis of Spin Density Matrix Elements in photon, proton to phi, proton for the GlueX Experiment

The quark model has been successful in classifying the spectrum of mesons observed since the 1960s, however, it fails to explain some of the measured bound states. Lattice QCD predictions have shown that an excited gluonic field may contribute to the quantum numbers of the bound state and form hybrid mesons, such as qq-bar,g and ggg, where g is a constituent gluon. It is possible for some hybrids to possess traditionally forbidden quantum numbers which are known as exotics. The GlueX photoproduction experiment at Jefferson Lab in Newport News, VA is designed to study exotic mesons and to map their spectrum. A 12 GeV electron beam produces 9 GeV linearly polarized photons via coherent bremsstrahlung in a diamond radiator which are incident on a liquid hydrogen target. In order to determine the photon energy, the use of a tagging spectrometer which measures the energy of the post-bremsstrahlung electron is required. The tagger microscope is a scintillating fiber detector designed to measure the energy of electrons corresponding to the polarized photons. The main focus of this work is the design and construction of the tagger microscope electronics as well as the calibration of the microscope within the experiment. Additionally, the analysis of the reaction photon, proton to phi, proton, where phi decays to K+K-, is discussed. The measurement of the phi spin-density matrix elements are shown and compared with past data which are in agreement.


Prof. Richard Jones

Physics Department (primary)

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