Sivers function of sea quarks in the light-cone model

We calculate the Sivers function of (u) over bar and (d) over bar quarks using the overlap representation within the light-cone formalism. The light-cone wave functions of the proton are obtainedin terms of the vertical bar(q) over bar qB > Fock states motivated by the meson-baryon fluctuation model. We consider the final-state interaction at the level of one gluon exchange. In a simplified scenario, the Sivers function of (u) over bar and (d) over bar can be expressed as the convolution of the Sivers function of the pion inside the proton and the unpolarized distribution of (q) over bar inside the pion. The model parameters are fixed by fitting the unpolarized sea quark distributions to the known parameterizations. We present the numerical results for f(1)(perpendicular to(u) over bar /p)(x, k(T)(2)) and f(1)(perpendicular to(d) over bar /p)(x, k(T)(2)). The first transverse moment of the sea quark Sivers functions in our model are find to be negative and the magnitude is about 0.004 at most. (C) 2022 The Author(s). Published by Elsevier B.V.

Automated summary

We calculated the Sivers function of (u) over bar and (d) over bar quarks using the overlap representation within the light-cone formalism. The Sivers functions of (u) over bar and (d) over bar can be expressed as the convolution of the Sivers function of the pion inside the proton and the unpolarized distribution of (q) over bar inside the pion. The numerical results show that the first transverse moment of the sea quark Sivers functions in our model is negative and has a magnitude of up to 0.004.