Abstract
The common belief that the lightest supersymmetric particle (LSP) might be a neutralino, providing also the main Dark Matter (DM) component, calls for maximal detail in the study of the neutralino properties. Motivated by this, we consider the direct production of a single neutralino $\tchi^0_i$ at a high/energy hadron collider, focusing on the $\tchi^0_1$ and $\tchi^0_2$ cases. At Born level, the relevant subprocesses are $q\bar q\to \tchi^0_i \tilde g$, $g q\to \tchi^0_i \tilde q_{L,R}$ and $q\bar q'\to \tchi^0_i\tchi^\pm_j$; while at 1-loop, apart from radiative corrections to these processes, we consider also $gg\to \tchi^0_i\tilde{g}$, for which a numerical code named PLATONgluino is released. The relative importance of these channels turns out to be extremely model dependent. Combining these results with an analogous study of the direct $\tchi^0_i\tchi^0_j$ pair production, should help in testing the SUSY models and the Dark Matter assignment.