deeply virtual compton scattering at 12 gev – e12-06-119
DESCRIPTION
Deeply Virtual Compton Scattering at 12 GeV – E12-06-119. Q hard 2 large. t = Δ 2. low -t process : -tTRANSCRIPT
Deeply Virtual Compton Scattering at 12 GeV – E12-06-119
Qhard2 large t = Δ2
low -t process :
-t << Qhard2
Mueller, Ji, Radyushkin (94-96)
x + ξ x - ξ
P - Δ/2 P + Δ/2GPDs (x, ξ ,t)Mostly H for unpolarized proton target
Mostly H for polarized proton target~
The DVCS amplitude is expressed in terms of Compton Form Factors at LO:
(same for other GPDs)
The E12-06-119 proposal aims at measuring the Beam Spin and Target Spin Asymmetrieswith unprecedented accuracy over the wide CLAS12 kinematical range
using 80 (LH2) + 120 (polarized NH3) days of beam time
The E12-06-119 proposal aims at measuring the Beam Spin and Target Spin Asymmetrieswith unprecedented accuracy over the wide CLAS12 kinematical range
using 80 (LH2) + 120 (polarized NH3) days of beam time
Beam Spin Asymmetry
From 1% statistical error on extracted Twist-2 coefficient
to 10% statistical errorat high xB
IC in standard position – 80 days – 10^35 Lum – VGG model
Target Spin Asymmetry
IC in standard position – 120 days – 2x10^35 Lum – VGG model
Global fits by H. Moutarde, H only (PRD79, 094021 (2009)) CLAS12 pseudo data, 80 days of beam time
Global fits by H. Moutarde, H only (PRD79, 094021 (2009)) CLAS12 pseudo data, 80 days of beam time
Extracted Compton Form Factor – From 6 to 12 GeV
Projected results
Building a profile of the nucleon at different xB