The production of charged-kaon pairs in proton-antiproton collisions: The role of higher-twist mechanism

The higher-twist (HT) contribution to the charged kaon pair production in the high energy proton-antiproton collisions at large transverse momentum $p_T$ is investigated by using the frozen coupling constant approach for various kaon distribution amplitudes (DAs), which are predicted by light-cone formalism, the light-front quark model, the nonlocal chiral quark model and the light-front holographic AdS/CFT approach. In the numerics the dependencies of the HT contribution on the transverse momentum $p_T$, the rapidity $y$, and the variable $x_T$ are discussed with special emphasis put on DAs. The HT contribution is also compared with the leading-twist ones. It is shown that the HT contributions are dependent on the kaon DAs and also some other phenomenological parameters such as momentum cut-off parameter $\Delta p$. Inclusive kaon pair production presents a remarkable test case in which HT terms dominate those of LT in certain kinematic regions. The HT direct production process via gluon-gluon fusion contributes significantly to the inclusive cross section at large $p_T$.