# 8th Workshop of the APS Topical Group on Hadronic Physics

10-12 April 2019
Denver, CO
US/Mountain timezone

## Extraction of the pion form factor from pion electroproduction

10 Apr 2019, 16:50
25m
Director's Row J (Denver, CO)

### Director's Row J

#### Denver, CO

Sheraton Denver Downtown Hotel, 1550 Court Pl. lobby level of the Plaza building
invited talk

### Speaker

Prof. Anthony Thomas (CSSM and CoEPP, University of Adelaide)

### Description

In 2008 the Jefferson Laboratory F_pi-2 Collaboration released results for the pion electromagnetic form factor, which they had extracted from pion electro-production data. The measured values for the pion form factor were extracted using the Vanderhagen, Guidal and Laget Regge Model. While agreement betweenthis model and data is impressive, the theoretical implementation of gauge invariance is less satisfying. We aim to establish how well the extracted form factor corresponds to the true form factor. To do this, we use a simple toy model, which imposes gauge invariance in a more theoretically satisfying way. The model form factor is extracted from our model cross section using the method employed by the F_pi-2 Collaboration to extract the experimental pion form factor. We conclude that while the reconstructed model form factor is a reasonable representation of the true model form factor for the kinematics chosen, the extracted form factor is somewhat smaller than the true form factor. This suggests that current extracted values of pion form factor may be overestimated.

### Primary author

Prof. Anthony Thomas (CSSM and CoEPP, University of Adelaide)

### Co-authors

Dr Ayse Kizilersu (CSSM, University of Adelaide) Mr Robert Perry (CSSM and CoEPP, University of Adelaide)

 Slides