Disclaimer: These pages describe the Global Muon Trigger in use in the Compact Muon Solenoid (CMS) Experiment from 2008 to 2015. The micro Global Muon Trigger (uGMT) , in use in CMS from 2016, is described at: https://twiki.cern.ch/twiki/bin/viewauth/CMS/L1MicroGlobalMuonTrigger (CMS internal)

Design: Hannes Sakulin, Anton Taurok

Integration: Ivan Mikulec, Tobias Nöbauer

Institute for High Energy Physics of the Austrian Academy of Sciences

The main task of the Global Muon Trigger is to choose and sort the best four muon candidates from the regional muon triggers and pass them to the L1 Global Trigger together with their parameters.

The functionality must be configurable in order to keep sufficient flexibility necessary to adjust trigger rates to given conditions without a loss in efficiency.

The Global Muon Trigger fulfils these functions:

Synchronise incoming muon candidates.
Merge or suppress duplicate muon candidates.
Assign rank and quality to outgoing muon candidates.
Assign MIP and isolation property based on the calorimeter information to outgoing muon candidates.
Store the information about the input and output muon candidates with event data.
Provide possibility to insert and read test patterns at the input and output of the module.

The logic of the board is programmed in 10 FPGA's mounted each on a separate mezzanine card.

The modul works in a deadtimeless 40 MHz pipeline mode with a latency smaller than 3.2 microseconds