Super-Level 1

This note describes a secondary vertex trigger algorithm for the LHCb experiment which uses information not only from the vertex detector, but also from muons and calorimeter clusters found in the lowest trigger level. The potential of an algorithm using this information to identify different B decay topologies at the vertex trigger level is examined. A concrete implementation is discussed in detail, together with the physics performance and limitations at each step of the algorithm. It is shown that the efficiency can be greatly enhanced relative to a pure secondary vertex based algorithm, in particular for B decays involving muons.