Fast timing hodoscope for CLAS12 and the first measurement of the γp → ωππp decay channel

Abstract

Meson spectroscopy aims to study the masses and decay processes of mesons to better understand the mechanics of Quantum Chromo Dynamics in the strong coupling (non peturbative) regime. The Edinburgh group are spokespersons on a major new proposal at the Thomas Jefferson National Laboratory called MesonEx. This experiment will make use of the newly upgraded 12 GeV electron beam and detector systems to produce and measure the properties of mesons of interest for study. Edinburgh also leads the development of a fast timing Hodoscope, part of the new Forward Tagger detector system that will be essential to the success of this experiment. The primary focus of this thesis is the development process of the Foward Tagger Hodoscope, from its inception up to its installation at Jefferson Lab. The second part of the document will discuss the first measurement of the γp → ωππp decay channel, with data from the g11a run of the CLAS (CEBAF Large Acceptance Spectrometer) in Hall B of Jefferson Lab. The analysis presents evidence for resonant contributions to the dataset decaying directly to ωππ, via b1(1235)π or via ωρ. These include a2(1320), π1(1600), ω3(1670) and π2(1670).