Threshold Pion Electroproduction at Large Momentum Transfers

TL;DR

This paper investigates pion electroproduction near threshold at high momentum transfers (1-10 GeV^2) using light-cone sum rules, providing predictions for cross sections and comparing with experimental data.

Contribution

It introduces a calculation of S-wave multipoles at threshold in the chiral limit for high Q^2 using light-cone sum rules, including P-wave contributions.

Findings

Predictions for cross sections in the threshold region.

Comparison with SLAC E136 data on structure function F2(W,Q^2).

Analysis of P-wave contributions' model independence.

Abstract

We consider pion electroproduction close to threshold for $Q^2$ in the region 1-10 GeV$^2$ on a nucleon target. The momentum transfer dependence of the S-wave multipoles at threshold, $E_{0+}$ and $L_{0+}$, is calculated in the chiral limit using light-cone sum rules. Predictions for the cross sections in the threshold region are given taking into account P-wave contributions that, as we argue, are model independent to a large extent. The results are compared with the SLAC E136 data on the structure function $F_2(W,Q^2)$ in the threshold region.