Method for simulating electroweak top-quark production events in the NLO approximation: SingleTop event generator

A new method for simulating electroweak top-quark production processes is described along with its computer realization in the SingleTop event generator. Special attention is paid to the correct combination of events from two parts of the main t-channel production process: 2 --> 2 with a b quark in the initial state and 2 --> 3, where an additional b quark appears in the final state. Integration of these two contributions enables the generation of event samples including the first correction to the leading perturbation order, avoiding the double-counting problem and negative-weight events. The SingleTop generator is based on the complete set of the tree Feynman diagrams calculated by the CompHEP package.