A new evaluation of the Baldin sum rule

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Abstract
The Baldin sum rule for the nucleon has been recalculated at the light of the most recent photoabsorption cross section measurements. The proton value (alpha + beta)_p =13.69 +/- 0.14 is smaller but consistent with the one usually quoted in literature. However, the value for the neutron (alpha + \beta)_n =14.40 +/- 0.66 turns out to be three standard deviations away from the previously calculated one.