Precision Measurements of the Charged Pion, Charged Kaon, and Proton Electromagnetic Form Factors at s = 13.48 GeV^2

TL;DR

This study provides the first precise measurements of the electromagnetic form factors of charged pions, kaons, and protons at a timelike momentum transfer of 13.48 GeV^2, using e+e- annihilation data.

Contribution

It presents the first identified measurements of pion and kaon form factors at |Q^2| > 4 GeV^2, expanding understanding of hadronic structure at high momentum transfers.

Findings

Measured |F_pi(13.48 GeV^2)| = 0.075 +- 0.008(stat) +- 0.005(syst)

Measured |F_K(13.48 GeV^2)| = 0.063 +- 0.004(stat) +- 0.001(syst)

Proton magnetic form factor |G^p_M(13.48 GeV^2)| = 0.014 +- 0.002(stat) +- 0.001(syst)

Abstract

Using 20.7 pb^-1 of e+e- annihilation data taken at sqrt{s} = 3.671 GeV with the CLEO-c detector, precision measurements of the electromagnetic form factors of the charged pion, charged kaon, and proton have been made for timelike momentum transfers of |Q^2| = 13.48 GeV^2 by the reaction e+e- -> h+h-. The measurements are the first ever with identified pions and kaons of |Q^2| > 4 GeV^2, with the results |F_pi(13.48 GeV^2)| = 0.075 +- 0.008(stat) +- 0.005(syst) and |F_K(13.48 GeV^2)| = 0.063 +- 0.004(stat) +- 0.001(syst). The result for the proton, assuming |G^p_E| = |G^p_M|, is |G^p_M(13.48 GeV^2)| = 0.014 +- 0.002(stat) +- 0.001(syst), which is in agreement with earlier results.