Twist-3 e(x) PDF as a sandbox for integral constraints in QCD phenomenology
by
Small Seminar Room
510
Parton Distribution Functions (PDFs) encode essential information about non-perturbative dynamics inside hadrons and are extracted from data through inverse problems, for which functions (not only parameters) are inferred. One of the challenges that global analyses face is the inclusion of integral constraints, or moments, provided by first principles, such as sum rules or lattice determinations. We explore how to enforce moments as hard constraints using Bézier curves, We apply this method to the analysis of the twist-3 PDF e(x), that is related to the sigma pion nucleon under integration, as well as to the quark mass via equations of motion. Due to limited experimental access, e(x) is an ideal sandbox for testing interpolation techniques and information-theoretic criteria that guide functional inference and capture epistemic uncertainty. We present preliminary extractions of e(x) from CLAS12 dihadron SIDIS data (beam-spin asymmetry on an unpolarized target), and discuss implications for isolating the genuine twist-3 quark–gluon–quark contribution.
Bjoern Schenke