The HERA-B SLT Group's Homepage

The Second Level Trigger (SLT) is a Region-of-Interest (RoI) based algorithm, running on a farm of 240 Pentium II/III PC's under the Hera-B data acquisition system.
It has been designed to trigger on signatures of charged lepton or hadron pairs, seeded by the First Level Trigger (FLT) output candidates. The main SLT functionalities are:


- Refine the track candidates from the FLT using all tracking stations downstream of the Hera-B Magnet

- Transport the track candidates through the Magnet into the Silicon Vertex Detector

- Apply a dilepton vertex cut (J/Psi) and eventually a detached vertex cut to the track pair candidates

The system was designed to handle 50KHz input rate, for a background reduction factor of about 100. The design efficiency on J/psi is at the ~90% level.

People in the SLT group

Talks

Notes and Publications

Meetings

News of the SLT

SLT versions

SLT 2000/2001 analysis

SLT simulation

Planning

Task Specific Instructions

• Old Page of SLT/DAQ projects
• Old L2simu frame