Measurement of generalized from factors near the pion threshold in high Q2 region with CLAS

Conference · Mon Feb 01 00:00:00 EST 2010

OSTI ID:1996809

Park, Kijun

The recent development of experimental techniques allow us to study threshold pion production in high-energy experiments and particularly, electro-production with photon virtuality Q2 in a few GeV2 range. The experiments with fine energy resolution make a major step to come close to the production threshold to suppress the P-wave contribution (M1+). The recent prediction based on the Light-Cone Sum Rule (LCSR), one can calculate the hadron form factors in terms of distribution amplitudes that approach perturbative Quantum Chromo-Dynamics (pQCD) without other non-perturbative parameters in high energy regime. The extraction of the generalized form factors near the pion threshold are estimated by the S- wave multipole dominance in the LCSR framework. We extracted the generalized form factors for the first time in the exclusive channel ( ep?en?+) using CEBAF Large Acceptance Spectrometer (CLAS) at Jefferson Lab. The kinematic ranges are from 2.05GeV2 to 4.5GeV2 for Q2 and 1.11GeV to 1.15GeV for the invariant mass range in the n?+ system.. Preliminary results will be presented and compared with the calculation from LCSR, MAID and multipole analysis.

• 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: 1996809
• Report Number(s): JLAB-PHY-10-1344; DOE/OR/23177-7060
• Resource Relation: Conference: APS April Meeting 2010, February 13–16, 2010; Washington, DC
• Country of Publication: United States
• Language: English