A new determination of ST 〈N|qDμDνq|N〉 based on recent experimental constraints

1ECT*, Villa Tambosi, 38123 Villazzano (Trento), Italy 2Institute of Physics and Applied Physics, Yonsei University, Seoul 120-749, Korea (Dated: March 30, 2015) Abstract The symmetric and traceless part of the matrix element ST 〈N|qDμDνq|N〉 can be determined from the second moment of the twist-3 parton distribution functi on e(x). Recently, novel experimental data on e(x) have become available, which enables us to evaluate the magn itude of the above matrix element with considerably reduced systematic uncertainties. Base d on the new experimental data, we show that ST 〈N|qDμDνq|N〉 is likely to be at least an order of magnitude smaller than wha t previous model-based estimates have so far suggested. We discuss the consequence s of this observation for the analysis of deep inelastic scattering and QCD sum rules studies at finite dens ity for the vector meson and the nucleon, in which this matrix element is being used as an input parameter .