Deep Exclusive PI0 and ETA Electroproduction with CLAS at Jefferson Lab
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 (TJNAF), 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
- Resource Relation:
- Conference: APS April Meeting 2012, March 31–April 3 2012; Atlanta, Georgia
- Country of Publication:
- United States
- Language:
- English
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