arXiv:2001.05366·v1·High Energy Physics — Lattice
Structure functions from the Compton amplitude
QCDSF-UKQCD-CSSM collaboration: Roger Horsley (Edinburgh U)🇬🇧 · Yoshifumi Nakamura (RIKEN)🇯🇵 · Holger Perlt (Leipzig U)🇩🇪 · Paul E. L. Rakow (Liverpool U)🇬🇧 · Gerrit Schierholz (DESY)🇩🇪 · Kim Somfleth (Adelaide U)🇦🇺 · Ross D. Young (Adelaie U)🇦🇺 · James M. Zanotti (Adelaide U)🇦🇺
Abstract
We have initiated a program to compute the Compton amplitude from lattice QCD with the Feynman-Hellman method. This amplitude is related to the structure function via a Fredholm integral equation of the first kind. It is known that these types of equations are inherently ill--posed - they are, e.g., extremely sensitive to perturbations of the system. We discuss two methods which are candidates to handle these problems: the model free inversion based on singular value decomposition and one Bayesian type approach. We apply the Bayesian method to currently available lattice data for the Compton amplitude.
Comments: 7 pages, 5 figures, poster presented at the 37th International Symposium on Lattice Field Theory (Lattice 2019), 16-22 June 2019, Wuhan, China