Evaluation of the Gottfried sum with use of the truncated moments method

Abstract

We reanalyze the experimental NMC data on the nonsinglet structure function $F_2^p-F_2^n$ and E866 data on the nucleon sea asymmetry $\bar{d}/\bar{u}$ using the truncated moments approach elaborated in our previous papers. With help of the special truncated sum one can overcome the problem of the unavoidable experimental restrictions on the Bjorken $x$ and effectively study the fundamental sum rules for the parton distributions and structure functions. Using only the data from the measured region of $x$, we obtain the Gottfried sum $\int_0^1 F_2^{ns}/x\, dx$ and the integrated nucleon sea asymmetry $\int_0^1 (\bar{d}-\bar{u})\, dx$. We compare our results with the reported experimental values and with the predictions obtained for different global parametrizations for the parton distributions. We also discuss the discrepancy between the NMC and E866 results on $\int_0^1 (\bar{d}-\bar{u})\, dx$. We demonstrate that this discrepancy can be resolved by taking into account the higher-twist effects.