[Deeppwg] Message from Piotr Konczykowski (abstract to ICHEP2010)

[Franck Sabatie]

Dear all,

Piotr Konczykowski has trouble sending message to the DWG mailing
list. He would like everyone to comment on the following abstract to
ICHEP2010 in Paris. Please send comments directly to him :

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The nucleon structure remains a fundamental question in hadronic
physics despite more than 50 years of experimental scrutiny. Its first
descriptions were based on Form Factors (FFs) and Parton Distribution
Functions (PDFs) accessible through elastic and deep inelastic
scattering respectively. Over the past decade there has been an
intense theoretical and experimental activity to unify these two
approaches which ensued from the development of the Generalized Parton
Distributions (GPDs). GPDs parameterize the non-perturbative content
of the nucleon. Linked to both FFS and PDFs, they correlate the
information in position and momentum spaces, allowing for the first
time to have access to a 3-dimensional picture of the nucleon. The
simplest way to measure the GPDs is through the measurement of the
Virtual Compton Scattering process in the Deeply Virtual region
(DVCS).


This presentation will focus on the DVCS Beam Spin Asymmetry
measurement performed by using data collected with the CLAS
spectrometer housed in the Hall B of Jefferson Lab.

The corresponding experiment was the first one dedicated to DVCS in
Hall B. It took place in two separate runs, the first one in 2005 and
the last in 2008-2009 with a slightly modified setup with respect to
the first part. Results obtained from the 2005 experiment will be
shown. A description of the recently completed second part of the
experiment and corresponding preliminary results will be given as
well.

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