Single neutralino production at CERN LHC

The common belief that the lightest supersymmetric particle might be a neutralino, providing also the main dark matter component, calls for maximal detail in the study of the neutralino properties. Motivated by this, we consider the direct production of a single neutralino (chi) over tilde (0)(i) at a high/energy hadron collider, focusing on the (chi) over tilde (0)(1) and (chi) over tilde (0)(2) cases. At Born level, the relevant subprocesses are q (q) over bar ->(chi) over tilde (0<)(i)(g)over tilde>, gq ->(chi) over tilde (0)(i)(q) over tilde (L,R), and q (q) over bar'->(chi) over tilde (0)(i)(g) over tilde (+/-)(j); while at one-loop, apart from radiative corrections to these processes, we consider also gg ->(chi) over tilde (0)(i)(g) over tilde, 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 (chi) over tilde (0)(i)(chi) over tilde (0)(j) pair production should help in testing the supersymmetric models and the dark matter assignment.