# The 24th International Spin Symposium

18-22 October 2021
Matsue, Shimane Prefecture, Japan
Asia/Tokyo timezone

## Measurements of the exclusive neutral pion electroproduction at Jefferson Lab Hall A experiment E12-06-114

18 Oct 2021, 19:40
20m
Room 501 (Kunibiki Messe)

### Room 501

#### Kunibiki Messe

Parallel Session Presentation Form factors and GPDs

### Speaker

PO-JU LIN (CEA - Université Paris-Saclay / IJCLab - Orsay)

### Description

Generalized Parton Distributions (GPDs) provide a 3D picture of the nucleon by correlating the longitudinal momentum to the transverse position of the partons inside of it. In addition to the chiral-even GPDs, the Deeply Virtual Meson Production (DVMP) also gives access to the chiral-odd (transversity) GPDs and has been providing inputs for the understanding of them. The exclusive production of $\pi^0$, in the Bjorken limit, is expected to be dominated by the contribution of the longitudinally polarized virtual photon that involves only the chiral-even GPDs, but it turned out not to be the case as shown by the previous data with limited reach in $Q^2$. The large contribution from the transversely polarized photon has been suggested to be the consequence of the convolution of the transversity GPDs and the Distribution Amplitudes (DA) of the $\pi^0$. The Jefferson Lab Hall A experiment E12-06-114 extended the kinematic coverage in the quark valence regime, and has measured the cross section of exclusive $\pi^0$ production off protons at large values of $x_B$ (0.36, 0.48, and 0.60) and $Q^2$ (3.1 to 8.4 $\mathrm{GeV^2}$). In this talk, the results of the E12-06-114 measurement will be presented.

### Primary author

PO-JU LIN (CEA - Université Paris-Saclay / IJCLab - Orsay)