Determination of the effective strong coupling constant from CLAS spin structure function data

We present a new extraction of the effective strong coupling constant α_s,g1(Q²). The result agrees with a previous determination and extends the measurement of the low and high Q² behavior of α_s,g1(Q²) that was previously deduced from sum rules. In particular, it experimentally verifies the lack of Q²-dependence of α_s,g1(Q²) in the low Q² limit. This fact is necessary for application of the AdS/CFT correspondence to QCD calculations. We provide a parameterization of α_s,g1(Q²) that can equivalently be used to parameterize the Q²-dependence of the generalized Gerasimov–Drell–Hearn and Bjorken sums.