The GPD H̃ and spin correlations in wide-angle Compton scattering

• Published in: The European physical journal. A, Hadrons and nuclei Vol. 53; no. 6; pp. 1 - 12
• Main Author: Kroll, P.
• Format: Journal Article
• Language: English
• Published: Berlin/Heidelberg Springer Berlin Heidelberg 01-06-2017; Springer Nature B.V
• Subjects: Amplitudes; Correlation; Elastic scattering; Extraction; Form factors; Hadrons; Heavy Ions; Nuclear Fusion; Nuclear Physics; Particle and Nuclear Physics; Physics; Physics and Astronomy; Regular Article - Theoretical Physics
• ISSN: 1434-6001; 1434-601X
• DOI: 10.1140/epja/i2017-12326-2

.
Wide-angle Compton scattering (WACS) is discussed within the handbag approach in which the amplitudes are given by products of hard subprocess amplitudes and form factors, specific to Compton scattering, which represent 1/
x
-moments of generalized parton distributions (GPDs). The quality of our present knowledge of these form factors and of the underlying GPDs is examined. As will be discussed in some detail the form factor
R
A
and the underlying GPD ˜ are poorly known. It is argued that future data on the spin correlations
A
L
L
and/or
K
L
L
will allow for an extraction of
R
A
which can be used to constrain the large -
t
behavior of ˜ .