Deeply Virtual Compton Scattering experiment at Jefferson Lab Hall B , with CLAS12, large acceptance spectrometer.
New theoretical concepts, Generalized Parton Distributions (GPD), enable to probe with a dramatic accuracy the nucleon structure, and access the quark confinement in hadrons.
These distributions might be determined through exclusive reactions measurements as DVCS (deeply virtual Compton scattering) and the upgrade in energy of the CEBAF accelerator at Jefferson Lab is also aiming at this goal. The SPhN CLAS group considers these topics as its scientific priority.
Elastic scattering experiments enabled to access the nucleon space structure by measuring form factors. Deep inelastic scattering, through parton distribution functions, improved the knowledge about momentum distributions. GPDs are the new tool which will reach the quarks and gluons space distributions inside the nucleons. The DVCS experiments are fit to extract GPDs and the 11 GeV kinematic domain foreseen at JLab is a crucial step forward following the pionneering experiments performed in Hall A and B at JLab, at Hermes and H1.
The COMPASS collaboration at CERN is studying the possibility of DVCS experiments too, after 2010.
Central detector, from outside: the solénoid,the calorimeter, time of flight counters and the central tracker.
Dapnia is implied in the upgrade of CLAS to CLAS12 in the central region. A tracker project, using cylindrical Micromegas detectors, will surround the target zone. R and D is going on at SEDI with help of SPhN and SIS. JLab has ordered to SACM a design project for a 5T solenoid to be located in the same region.
Data analysis of previous DVCS experiments are progressing in collaboration with SPhN which is also implied in tracking simulations for CLAS12.
Jefferson Lab is located in the US, Newport-News Virginia, 350 km South East fromWashington DC
Michel GARÇON : co-spokesman of the CLAS-DVCS experiment chaired the CLAS Collaboration until September 2007.
Franck SABATIÉ: co-spokesman of Hall A DVCS experiment at JLab, is co-spokesman of an approved CLAS12 DVCS experiment.
Jacques BALL : scientific leader of the CLAS12-Tracker project.
last update : 03-16 00:00:00-2010 (2264)