2010/04/30 by Sonny Mantry, Michael J. Ramsey-Musolf, Gian Franco Sacco
Physics and Astronomy · #High-Energy Particle Collisions Research #Particle physics theoretical and experimental studies #Quantum Chromodynamics and Particle Interactions #hep-ph #nucl-ex #nucl-th
paper · pdf · doi:10.1103/physrevc.82.065205
published as Phys.Rev.C82:065205,2010 · 27 pages, 3 figures, typos fixed, version accepted for publication in Physical Review C
arxiv created 2010/12/21 · openalex publication_date 2010/12/27 · arxiv updated 2011/01/28 · openalex created_date 2016/06/24 · openalex updated_date 2026/07/28
We show that parity-violating deep-inelastic scattering (PVDIS) of longitudinally polarized electrons from deuterium can in principle be a relatively clean probe of higher twist quark-quark correlations beyond the parton model. As first observed by Bjorken and Wolfenstein, the dominant contribution to the electron polarization asymmetry, proportional to the axial vector electron coupling, receives corrections at twist four from the matrix element of a single four-quark operator. We reformulate the Bjorken-Wolfenstein argument in a matter suitable for the interpretation of experiments planned at the Thomas Jefferson National Accelerator Facility (JLab). In particular, we observe that because the contribution of the relevant twist-four operator satisfies the Callan-Gross relation, the ratio of parity-violating longitudinal and transverse cross sections, R^\ensuremathγZ, is identical to that for purely electromagnetic scattering, R^\ensuremathγ, up to perturbative and power-suppressed contributions. This result simplifies the interpretation of the asymmetry in terms of other possible novel hadronic and electroweak contributions. We use the results of MIT Bag Model calculations to estimate contributions of the relevant twist-four operator to the leading term in the asymmetry as a function of Bjorken x and Q2. We compare these estimates with possible leading twist corrections from violation of charge symmetry in the parton distribution functions.