Study of the process $e^+e^-\to p\bar{p}$ in the c.m. energy range from threshold to 2 GeV with the CMD-3 detector

TL;DR

This study measures the cross section of the process $e^+e^- o par{p}$ in the 1.88 to 2 GeV energy range using the CMD-3 detector, providing insights into proton electromagnetic form factors.

Contribution

The paper presents the first measurement of the $e^+e^- o par{p}$ cross section in this energy range with high precision and extracts the ratio of electric to magnetic form factors.

Findings

Cross section measured at 12 energy points with 6% systematic uncertainty.

Ratio of electric to magnetic form factors determined as 1.49 ± 0.23 ± 0.30.

Provides data crucial for understanding proton structure in the time-like region.

Abstract

Using a data sample of 6.8 pb$^{-1}$ collected with the CMD-3 detector at the VEPP-2000 $e^+e^-$ collider we select about 2700 events of the $e^+e^- \to p\bar{p}$ process and measure its cross section at 12 energy ponts with about 6\% systematic uncertainty. From the angular distribution of produced nucleons we obtain the ratio $|G_{E}/G_{M}| = 1.49 \pm 0.23 \pm 0.30$.