A precision description of deuteron electromagnetic form factors at low Q$^2$

ORAL

Abstract

I will discuss the use of chiral effective theory ($\chi$ET) to compute the form factors $G_C$, $G_Q$, and $G_M$ that are measured in elastic electron-deuteron scattering. I will show that NN potentials derived from $\chi$ET, when used in concert with the $\chi$ET current operators, give an accurate description of the ratio $G_Q/G_C$ for momentum transfers $\sqrt{Q^2} < 0.6$ GeV. I will describe ongoing work to achieve similar precision for the magnetic form factor $G_M$. I will also show a prediction for the charge form factor $G_C$ that is based on a $\chi$ET calculation at $O(eP^5)$. Such a prediction should be accurate up to corrections of order 1--2\% for momentum transfers $\sim M_\pi^2$. I will explain how this uncertainty grows with $Q^2$, and then close by showing the resulting $\chi$ET prediction (including theoretical uncertainties) for $A(Q)$ in the range $\sqrt{Q^2} < 0.7$ GeV. This prediction can be compared to recent JLab data on $A(Q)$, taken in the range $0.2 < \sqrt{Q^2} < 0.7$ GeV.

Authors

  • Daniel Phillips

    Ohio University