Deep Virtual Compton Scattering e p e p g

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Deep Virtual Compton Scatteringe p ? e p g
Q2 -q2 -(k-k)2 gtgt LQCD2, s (qp)2
gtgtM2, -t -(p-p)2 ltlt Q2
q
c.t.
QCD Factorization (Ji, Radyushkin, Collins
Freund et al)
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E00-110 ComponentsClermont-Ferrand, Saclay, ODU,
Rutgers, JLab
PbF2 Calorimeter 132 elements
Electronics
Proton Array
100 elements
Scattering chamber
Support structure
PbF2 and Proton array PMTs operate at low gain
with active bases. Gain monitoring with blue LEDs.
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Phase Space Densities (Wigner Distributions) of
Quarks inside the Proton, for Short, Medium, and
Long wavelength quarks.
Scale is 1 fm ? r.m.s. charge radius of proton.
Wavelength ? h/(Mx)
Courtesy, X. Ji, UMd
Surfaces of constant density