Re-evaluation of the Gottfried sum using neural networks

We provide a determination of the Gottfried sum from all available data, based on a neural network parametrization of the nonsinglet structure function F2. We find SG=0.244+/-0.045, closer to the quark model expectation SG=1/3 than previous results. We show that the uncertainty from the small x region is somewhat underestimated in previous determinations.