The Search for Exotic Mesons in the 3$$\pi$$ System in Photoproduction with CLAS

Conference · Fri May 01 04:00:00 EDT 2009

OSTI ID:1999626

Bookwalter, Craig

In addition to ordinary qq¯ pairs, quantum chromodynamics (QCD) permits many other possibilities in meson spectra, such as gluonic hybrids, glueballs, and tetraquarks. Experimental discovery and study of these exotic states provides insight on the nonperturbative regime of QCD. Over the past twenty years, some searches for exotic mesons have met with controversial results, especially those obtained in the three-pion system. Prior theoretical work indicates that in photoproduction one should find gluonic hybrids at significantly enhanced levels compared to that found in pion production. To that end, the CLAS g12 run was recently completed at Jefferson Lab, 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 3π photoproduction dataset, with 3π events numbering in the millions. Early results describing the data quality, kinematics, and dynamics will 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: 1999626
• Report Number(s): JLAB-PHY-09-983; DOE/OR/23177-0831
• Country of Publication: United States
• Language: English