Probing Hadron Structure through exclusive π⁰ electoproduction.

Complementary to Deeply Virtual Compton Scattering (DVCS), the exclusive π⁰ channel (pseudo-scalar mesons) offers crucial insights into the Generalized Parton Distributions (GPDs) of the nucleon, essential for understanding its three-dimensional structure. The initial cross-section measurements for exclusive π⁰ electroproduction in the valence region, performed in Hall A at Jefferson Lab, revealed significant contributions from transversely polarized virtual photons. This finding starkly contrasts with the handbag factorization approach, which predicts the dominance of longitudinally polarized photons at asymptotically large photon virtualities Q². According to the handbag model, the amplitudes for transverse photons should be suppressed by a factor of ∼1/Q compared to those for longitudinal photons.

Nevertheless, substantial transverse photon contributions enable the exploration of transversity GPDs. Evidence of significant longitudinal-transverse (L-T) interference in π⁰ production is supported by measurements from CLAS and Hall A. Therefore, it is of significant interest to determine the relative contributions of longitudinal and transverse photons to the π⁰ cross section. This talk will discuss the measurement of exclusive π⁰ electroproduction in the recently completed Run Group-1 experiments in Hall C at Jefferson lab using Neutral Particle Spectrometer (NPS) aimed to assist in this study.