Deep Exclusive PI0 and ETA Electroproduction with CLAS at Jefferson Lab

Conference · Sun Apr 01 04:00:00 EDT 2012

OSTI ID:1993597

Stoler, Paul

The CLAS collaboration at Jefferson Lab has undertaken a series of measurements of exclusive $$\pi^0$$ and $$\eta$$ electroproduction at a beam energy ~ 6 GeV over a large kinematic coverage in $Q^2, t$ and $$x_B$$. New results of extracted structure functions $$\sigma_L+\sigma_T, \sigma_{LT}$$ and $$\sigma_{TT}$$, are presented in the kinematic range $Q^2$ from 1.2 to 3.2 GeV$^2$/c$^2$, $|t|$ from $$|t_{min}|$$ to 1.2 GeV$^2$/c$^2$ and $$x_B$$ from 0.1 to 0.6. Recent theoretical work [1,2] indicate that pseudoscalar meson production is uniquely sensitive to quark helicity-flip processes. The new results, together with CLAS measurements of beam spin asymmetries $$A_\phi$$ [3] and cross section ratios $$\sigma(\pi_0)/\sigma(\eta)$$ , compared with theoretical calculations [1,2] that are based on the helicity-flip transversity GPDs, provide supporting evidence that pseudoscalar meson production at these kinematics may be dominated by the handbag mechanism and helicity-flip transversity GPDs.

• 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: 1993597
• Report Number(s): JLAB-PHY-12-1738; DOE/OR/23177-6864
• Country of Publication: United States
• Language: English