Polarized structure function g$_{2}$ in the CM bag model

The spin-dependent structure functions g_1(x), g_2(x), {g}_2^{WW}(x) and {\bar g}_2(x) and their moments are studied in the CM bag model. The results show that (i) \int_0^1g_2(x)dx=0, i.e. the Burkhardt-Cottingham sum rule holds, hence g_2(x) must have at least one non-trivial zero besides x=0 and x=1. (ii) \int_0^1x^2g_2(x)dx is negative for the proton, neutron and deuteron. (iii) \int_0^1x^2g_2(x)dx is about one order of magnitude smaller than \int_0^1x^2g_1(x)dx, hence the twist-3 matrix element is approximately equal to the twist-2 matrix element. The results are compared with most recent data and predictions from the MIT bag model, lattice QCD and QCD sum rules