Momentum transfer dependence of the proton's electric and magnetic polarizabilities

The Q²-dependence of the sum of the electric and magnetic polarizabilities of the proton is calculated over the range 0≤Q²≤6 GeV² using the generalized Baldin sum rule. Employing a parametrization of the F₁ structure function valid down to Q²=0.06 GeV², the polarizabilities at the real photon point are found by extrapolating the results of finite Q² to Q²=0 GeV². We determine the evolution over four-momentum transfer to be consistent with the Baldin sum rule using photoproduction data, obtaining α+β=13.7±0.7×10¯⁴ fm³.N. L. Hall, A.W. Thomas and R. D. Youn