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Single p 0 Electroproduction in the Resonance Region with CLAS. Kyungseon Joo University of Connecticut For the CLAS Collaboration. N* 2009 Beijing, China April 19, 2009. SU(6)xO(3) Classification of Low Lying N*. C LAS. Exclusive Processes in N* Studies. p(e,e’)X. Hadronic mass.
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Single p0Electroproduction in the Resonance Region with CLAS Kyungseon Joo University of Connecticut For the CLAS Collaboration N* 2009 Beijing, China April 19, 2009
CLAS Exclusive Processes in N* Studies p(e,e’)X Hadronic mass
Transition Form Factors of Low Lying N* States pp0 channel is important to study: N* Transition Form Factors in the 2nd Resonance Region – “Roper” P11(1440), S11(1535), D13(1520)
Transverse amplitudes for g*p->D13(1520) + preliminary preliminary
CLAS Single Pion Electro-production Data Data in the D(1232) region up to W = 1.4 GeV
CLAS Single Pion Electro-production Data Data up to the 3rd resonance region up to W = 1.7 GeV
CLAS Single p0 Electro-production Data Analysis • E1E: • Beam Energy:1 GeV and 2 GeV • Low Q2 up to 1.5 GeV, and W up to 1.7 GeV • E1-6: • Beam Energy: 5.75 GeV • Low Q2, up to 4.5 GeV and W up to 2.0 GeV • Beam polarization: ~ 70 – 80 % • Target: Liquid Hydrogen
CEBAF at Jefferson Lab Emax ~ 6 GeV Imax ~ 200 mA Duty Factor ~ 100% sE/E ~ 2.5 10-5 Beam P ~ 80% Eg(tagged) ~ 0.8- 5.5 GeV CLAS B C A
CEBAF Large Acceptance Spectrometer (CLAS) • Six identical sectors • 5 T toroidal B-field • Δθ=15-140 degrees • Δφ= 0-50 degrees • Δp/p = 10-2-10-3
Proton PID Use TOF timing and DC momentum of positive tracks
p0 selection e + p -> e’ + p + X on D(1232) resonance region from 5.7 GeV MX2 MX2 MX2 from e + p -> e’ + p + X on D(1232) resonance region from 2. 0 GeV
p0 selection (E1-6) MX2 from e + p -> e’ + p + X for 1.1 < W < 2.0 GeV Mgg2 MX2 Currently working on bench-mark studies on D(1232) region with/without tagging p0
Typical ep→ e’pπ0 cross sections vs cos θ* and φ* Q2 = 0.2 GeV2 W=1.22 GeV Very preliminary
π+ electroproduction at Q2=0.20 GeV2 using CLAS Very preliminary
Differential Cross section from 2.0 GeV 0.6 < Q2 < 0.7, 1.3 < W < 1.35 Very preliminary
Legendre Moment A0 0.6 < Q2 < 0.7 Very preliminary
pπ0 only nπ+ only pπ0 and nπ+ E1+/M1+ and S1+/M1+ CLAS e1e UIM Fit
Transverse amplitudes for g*p->D13(1520) + preliminary preliminary
Summary • Single p0 electro-production analysis is under way • for low and high Q2 range up to 2.0 GeV in W. • Able to perform combined analysis with np+ and two pion • channels • pp0 channel is an important part of 12 GeV N* program • with CLAS12. • Current pp0 analysis measuring all final states will provide • an important step for 12 GeV N* program.