Measurements of Hadron Form Factors at BESIII

TL;DR

This paper reports on measurements of hadron form factors at BESIII using various processes and energies, providing new experimental data and preliminary results that enhance understanding of baryon electromagnetic structure.

Contribution

It presents new experimental measurements of hadron form factors from BESIII at multiple energies, including preliminary results on Lambda baryons and summaries of pion form factor measurements.

Findings

Measured $e^+e^- ightarrow par{p}$ form factors from 2011-2012 data.

Presented preliminary results on $e^+e^- ightarrow ext{Lambda}ar{ ext{Lambda}}$.

Summarized pion form factor measurements at 3.773 GeV.

Abstract

BEPCII is a symmetric $e^+e^-$-collider located in Beijing running at center-of-mass energies between 2.0 and 4.6 GeV. This energy range allows the BESIII-experiment to measure hadron form factors both from direct $e^+e^-$-annihilation and from initial state radiation processes. In this paper, results on $e^+e^-\rightarrow p\bar{p}$ based on data collected by BESIII in 2011 and 2012 are presented. We also present preliminary results on $e^+e^-\rightarrow \Lambda \bar{\Lambda}$ based on the same data samples at 4 center-of-mass energies. BESIII results obtained from $e^+e^-\rightarrow \pi^+\pi^-$ using the initial state radiation technique at the center-of-mass energy of 3.773 GeV are also summarized. Finally, expectations on the measurement of baryon electromagnetic form factors from the BESIII high luminosity energy scan in 2015 and from initial state radiation processes at different center-of-mass energies are also reported.