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A lattice calculation of the nucleon's spin-dependent structure function g_2 revisited

M. Gockeler·R. Horsley·W. Kurzinger·H. Oelrich·D. Pleiter·P. E. L. Rakow·A. Schafer·G. Schierholz
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Abstract

Our previous calculation of the spin-dependent structure function g_2 is revisited. The interest in this structure function is to a great extent motivated by the fact that it receives contributions from twist-two as well as from twist-three operators already in leading order of 1/Q^2 thus offering the unique possibility of directly assessing higher-twist effects. In our former calculation the lattice operators were renormalized perturbatively and mixing with lower-dimensional operators was ignored. However, the twist-three operator which gives rise to the matrix element d_2 mixes non-perturbatively with an operator of lower dimension. Taking this effect into account leads to a considerably smaller value of d_2, which is consistent with the experimental data.

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M. Gockeler, R. Horsley, W. Kurzinger, H. Oelrich, D. Pleiter, P. E. L. Rakow, A. Schafer, G. Schierholz. 2000-11-30. A lattice calculation of the nucleon's spin-dependent structure function g_2 revisited. https://doi.org/10.1103/physrevd.63.074506

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