Markov chain Monte Carlo (MCMC) based Likelihood Extraction of Chiral-Odd Compton Form Factors from Deeply Virtual Exclusive Experiments

Abstract

We present a likelihood analysis of observables in deeply virtual exclusive meson production off the proton. The study uses experimental data for cross sections together with beam and target spin asymmetries measured in the unpolarized beams and unpolarized as well as longitudinally polarized target configurations at Jefferson Lab Halls A and B. For a fixed kinematic bin defined by $(Q^2,x_B,t,ϵ)$, we derive a joint likelihood for the twist-two chiral-odd helicity amplitudes and the corresponding Compton Form Factors (CFFs), that parameterize the underlying QCD scattering amplitude. The joint likelihood analysis of cross-section and Asymmetry data strongly constrains the CFF parameter space beyond the either of the measurements studied alone. Markov chain Monte Carlo (MCMC) methods are employed to explore the full parameter space, extracting the parameter uncertainties, correlations and credible intervals.

Comments: 6 pages, 5 figures, AI4EIC conference, accepted in JINST