Neutralino pair production at proton-proton collider

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