Eur Phys J C (2004) 33: s1035-s1037
https://doi.org/10.1140/epjcd/s2004-03-1804-1

PS14 Detectors and Data Handling

CMS high-level trigger selection

Istituto Nazionale di Fisica Nucleare, Pisa, Italy

Received: 31 October 2003
Accepted: 10 March 2004
Published online: 31 March 2004

Abstract

The CMS High-Level Trigger (HLT) is based on sets of dedicated commercial processors, whose goal is to reduce the Level-1 trigger rate of 100 kHz to ≈100 Hz, a value compatible with permanent storage of data. In this report the results from the recently published DAQ TDR are presented. The offline code with little modifications can be used in the trigger chain soon after Level 1 by making use of regional and conditional analyses. For the benchmark channels considered, the signal efficiencies and background rejection factors, obtained within ≈500 ms of a recent CPU (1 GHz processor), are competitive with full offline analyses done without any timing limitation.

PACS: CMS Compact muon solenoid experiment – HLT High-Level Trigger