Examination of Wandzura-Wilczek relation for g2(x, Q2) in pQCD

In order to examine the validity of Wandzura-Wilczek relation for the polarized DIS structure function g2(x, Q2), we use the light-front time-ordering pQCD to calculate g2(x, Q2) at order αs on a quark target. We find that the study of the transverse polarized structure function in pQCD is only meaningful if we begin with massive quarks. The result shows that the Wandzura-Wilczek relation for g2(x, Q2) is strongly violated by the quark mass in pQCD.