last update: Feb 2014
Deeply Virtual Compton Scattering
New QCD factorization theorems establish that exclusive
such as H(e,e'γ)p and H(e,e'π0)p,
in the deeply
virtual limit of large Q2, W, and -t< Q2
are determined (in leading twist, or
leading term in an expansion in inverse powers of Q2)
by a new class of quark and
gluon matrix elements, called Generalized Parton Distributions
(GPDs). The GPDs correlate the transverse spatial distribution of the
struck parton (quark or gluon)
with the light-cone momentum fraction of the parton in the target.
Hall A experiment E00-110 measured the dependence of the
H(e,e'γ)p cross section at xBj=0.36 and
Q2 = 1.5, 1.9, and 2.3 GeV2.
The results are consistent with dominance of the leading twist
The experiment also measured the helicity independent
cross section at Q2 = 2.3 GeV2. The latter results show
evidence for strong contributions from both the Real part of the
BH*DVCS interference and
the pure |DVCS|2 terms (as well as the |BH|2 term).
approved by the JLab PAC30 in August, 2006. With a new calorimeter, the
DVCS and deep virtual π0 measurements in
xBj,Q2 to (0.7,9.0 GeV2 will be extended.
In PR07-007, approved by the JLab PAC31 in January, 2007,
DVCS measurements at fixed Q2, xBj and two different beam energies
(6 and 4 GeV) are proposed.
The kinematic structure of the ep→ epγ cross section
to separate the Real part of the BH*DVCS interference from the
pure |DVCS|2 term at all three Q2 values of the previous E00-110.
Rosenbluth L/T separations of the ep→ epπ0
cross section, which is crucial to testing factorization in this channel will be obtained.
Fourth generation (to be scheduled)
Third generation (upcoming data taking starting as soon as 2014)
Second generation (data taken in 2010, analysis
First generation (completed, see results)
Articles in peer-reviewed journals
- Second generation of experiment: E07-007 and E08-025. Ran in 2010.
- First generation of experiments: E00110 and E03106. Ran before
This list is incomplete (please contact JR if you want your talk
here). You may also want to consult C.Hyde's page
- Dec '13: E07-007/E08-025:
DVCS Experiment, C. Desnault, Hall A collaboration meeting
- July '13:The
GPD Program at Jefferson Laboratory, C. Hyde,
The Fifth Workshop on Hadron Physics in China and Opportunities in
- Dec '13:Deeply Virtual Compton
Scattering in Hall C at 11 GeV,
C. Hyde, Winter 2013 Hall C user meeting
- Aug '11:
E12-06-114, C. Munoz Camacho, JLab/PAC 38 presentation.
- Jan '07: Complete separation of deeply photon and π0 electro-production observables of unpolarized protons, C. Munoz Camacho, JLab/PAC 31 presentation.
- Jan '07: Outlook for Generalized Parton Distribution and Deeply Virtual Compton Scattering in Hall A, C.E Hyde-Wright, Hall A collaboration meeting.
- Jan '07: DVCS on the neutron in Jefferson Lab Hall A, C.E Hyde-Wright, Hall A collaboration meeting.
- Oct '06: DVCS cross section measurements at JLab, C. Munoz Camacho, Hard exclusive processes at JLab 12 GeV and a future EIC.
- Oct '06: π0 electro-production cross sections at JLab, C. Munoz Camacho, Hard exclusive processes at JLab 12 GeV and a future EIC.
- Aug '06: Deeply Virtual Compton scattering in Hall A with CEBAF at 12 GeV, C. Munoz Camacho, JLab/PAC30 presentation.
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