Higher twist analysis of the proton g1 structure function

We perform a global analysis of all available spin-dependent proton structure function data, covering a large range of Q2, 1⩽Q2⩽30GeV2, and calculate the lowest moment of the g1 structure function as a function of Q2. From the Q2 dependence of the lowest moment we extract matrix elements of twist-4 operators, and determine the color electric and magnetic polarizabilities of the proton to be χE=0.026±0.015(stat)±0.0240.021(sys) and χB=−0.013∓0.007(stat)∓0.0120.010(sys), respectively.