Exotic Meson spectroscopy at CLAS

Conference · Wed May 01 04:00:00 EDT 2013

OSTI ID:1991940

Weygand, Dennis ^[1]

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1. Thomas Jefferson National Accelerator Facility (TJNAF), Newport News, VA (United States)

QCD models of hadrons have long suggested the existence of mesons beyond the Naive Quark Model (NQM). Observation of states outside of the NQM provides insight on the nonperturbative regime of QCD. There are suggestions that photoproduction of $$J^{PC}=1^{-+}$$ gluonic hybrids might be found at enhanced levels. To that end, the g12 experiment at Jefferson Lab's CEBAF Large Acceptance Spectrometer (CLAS) has recently acquired a high statistics photoproduction dataset, using a liquid hydrogen target and tagged photons from a 5.71 GeV electron beam. The CLAS experimental apparatus was modified to maximize forward acceptance for peripheral production of mesons. The resulting data contains the world's largest 3$$\pi$$ photoproduction dataset, with $$\gamma p \to \pi^+\pi^+\pi^-n$$ events numbering in the millions. Results of a partial-wave analysis in search of the exotic $$\pi_1(1600)$$ will be shown. In addition, an analysis of the reaction $$\gamma p \to \eta \pi^- \Delta^{++}$$, to search for the exotic $$\pi_1(1400)$$, will also be shown.

• Research Organization: Thomas Jefferson National Accelerator Facility, Newport News, VA (United States)
• Sponsoring Organization: USDOE Office of Science (SC), Nuclear Physics (NP)
• DOE Contract Number: AC05-06OR23177
• OSTI ID: 1991940
• Report Number(s): JLAB-PHY-13-1754; DOE/OR/23177-2613
• Country of Publication: United States
• Language: English