Neutralino pair production at proton-proton collider

In this paper we investigated the Drell-Yan process of the light neutralino pair $\tilde{\chi}^0_{i}\tilde{\chi}^0_{j}~(i,j=1,2)$ productions at hadron colliders. We studied the dependence of the coupling properties of two light neutralino $\tilde{\chi}^0_{1,2}$ on the three SUSY Lagrangian parameters $M_1$, $M_2$ and $\mu$, and find that the production rate of $\tilde{\chi}^0_1 \tilde{\chi}^0_2$ pair will be dominated by the Higgsino-like couplings under the condition $\mu \ll M_2$ and $\mu \sim M_1$, while the productions of $\tilde{\chi}^0_1\tilde{\chi}^0_1$ and $\tilde{\chi}^0_2\tilde{\chi}^0_2$ pairs will be enhanced by the gaugino-like couplings under $M_i \ll \mu$. For the Higgsino-like $\tilde{\chi}^0_{1,2}$ neutralinos, the cross section of $\tilde{\chi}^0_1\tilde{\chi}^0_2$ production at the LHC can reach $100~fb$.