Strangeness contribution to the vector and axial form factors of the nucleon

S. F. Pate; G. A. MacLachlan; D. W. McKee; V. Papavassiliou

doi:10.1063/1.2220254

paper

Strangeness contribution to the vector and axial form factors of the nucleon

arXiv:hep-ex/0512032 · doi:10.1063/1.2220254

Abstract

The strangeness contribution to the vector and axial form factors of the nucleon is presented for momentum transfers in the range $0.45 < Q^{2} < 1.0$ GeV $^{2}$ . The results are obtained via a combined analysis of forward-scattering parity-violating elastic $e p$ asymmetry data from the $G^{0}$ and HAPPEx experiments at Jefferson Lab, and elastic $ν p$ and $ν ˉ p$ scattering data from Experiment 734 at Brookhaven National Laboratory. The parity-violating asymmetries measured in elastic $e p$ scattering at forward angles establish a relationship between the strange vector form factors $G_{E}^{s}$ and $G_{M}^{s}$ , with little sensitivity to the strange axial form factor $G_{A}^{s}$ . On the other hand, elastic neutrino scattering at low $Q^{2}$ is dominated by the axial form factor, with still some significant sensitivity to the vector form factors as well. The combination of the two data sets allows the simultaneous extraction of $G_{E}^{s}$ , $G_{M}^{s}$ , and $G_{A}^{s}$ over a significant range of $Q^{2}$ for the very first time.

3 pages, 1 figure, will appear in AIP Conference Proceedings for PANIC 2005