The impact of s- anti s asymmetry on the strange electromagnetic form factor

The existence of the strange quark asymmetry in the nucleon sea has been indicated by both the experimental and theoretical analyses. Although it is well known that the s- anti s asymmetry is important for some processes in high-energy hadron collisions, it has also been indicated that it can be related to the strange Dirac form factor F₁^s. In this work, we have studied the impact of s- anti s asymmetry and its uncertainty from various modern parton distribution functions (PDFs) on F₁ ^s and compared the obtained results with the available experimental information. As a result, we found that the uncertainty in F₁^s(t) due to the s(x) - anti s (x) distribution is rather large so that it dominates the model uncertainty at all values of the squared momentum transfer t. However, taking into account the uncertainties, the theoretical predictions of F₁^s(t) are fully compatible with the estimate extracted from experiment. We concluded that the future accurate experimental data of the strange Dirac form factor might be used to put direct constraints on the strange content of the proton and reduce its uncertainty that has always been a challenge. (orig.)