Pion transverse charge density and the edge of hadrons

作者：Carmignotto Marco^*; Horn Tanja; Miller Gerald A

来源：Physical Review C, 2014, 90(2): 025211.

DOI：10.1103/PhysRevC.90.025211

We use the world data on the pion form factor for space-like kinematics and a technique previously used to extract the proton transverse densities to extract the transverse pion charge density and its uncertainty due the incomplete knowledge of the pion form factor at large values of Q(2) and the experimental uncertainties. The pion charge density at small values of impact parameter b %26lt; 0.1 fm is dominated by this incompleteness error while the range between 0.1-0.3 fm is relatively well constrained. A comparison of pion and proton transverse charge densities shows that the pion is denser than the proton for values of b %26lt; 0.2 fm. The pion and proton transverse charge densities seem to be the same for values of b = 0.3-0.6 fm. Future data from Thomas Jefferson National Accelerator Facility (JLab) 12 GeV and the Electron-Ion Collider (EIC) will increase the dynamic extent of the form factor data to higher values of Q(2) and thus reduce the uncertainties in the extracted pion transverse charge density.

• 出版日期2014-8-29