Mathphys seminar: Studying Generalized Parton Distribution in Holographic QCD(arXiv: 1105.2907)
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Asia/Tokyo
Main Research Building, room 248
Main Research Building, room 248
Description
日時：２月２７日(月) 15：30から１時間程度
Feb. 27th, 15:30-17:00
場所：研究本館248室（橋本数理物理研セミナー室）
Main Research Building, room 248
講師：渡利 泰山氏（東大IPMU）
Dr. Taizan Watari (IPMU, u Tokyo)
講演タイトル :
Studying Generalized Parton Distribution in Holographic QCD
(arXiv: 1105.2907)
Abstract:
Generalized parton distribution (GPD) contains rich information of
partons in a hadron, including transverse profile, and is also
non-perturbative information necessary in describing a variety of hard
processes, such as meson leptoproduction and deeply virtual Compton
scattering (DVCS). In order to unveil non-perturbative aspects of GPD,
we study DVCS at small x in gravitational dual description. Using the
complex spin j-plane representation of DVCS amplitude, we show that GPD
is well-defined and can be extracted from the amplitude even in the
strong coupling regime. It also turns out that the saddle point value in
the j-plane representation plays an important role; two phases---DGLAP
phase and Regge phase---appear in the imaginary part of the amplitude of
DVCS and GPD, depending on relative position of the saddle point and the
leading pole in the j-plane, and now we understand how crossover between
the two phases is triggered.
The saddle point value also directly controls kinematical variable
dependence of many observables in one of the two phases, and indeed the
dependence is qualitatively in nice agreement with HERA measurements.
Such observation that the gravity dual shares basic properties of the
real world QCD suggests that information from BFKL theory might be used
to reduce error in the gravity dual predictions of the form factor and
of GPD.
講演言語 Language：English