Local Performance of the Local Cathode Strip Chamber Trigger

in a Muon Beam Test

Overview:

• Introduction to LHC

• Overview of CMS

• Overview of Trigger Architecture

• Overview of Cathode Strip Chamber (CSC)

• Level-1 Trigger System

• Plots for efficiency

• Conclusion

LHC

• 14 TeV center of mass energy• 27 km circumference

CMS (Compact Muon Solenoid)

CMS

What is a muon?

Muons are point particles identical to electrons except over 200 times more massive (105.2 MeV)

The illustration shows the smaller orbit for muons in a hydrogynic atom due to their mass

CMS

Why Muons?

•Muons are penetrating.

•Electrons are too light to make it through absorbers

•Taus are too unstable to make it through absorbers

•Hadrons interact strongly with matter

Trigger Architecture

• Need Trigger System to filter out data

Cathode Strip Chambers (CSC)

• Provide 3-D tracks of charged particles called Local Charge Tracks (LCT’s)

Level-1 Trigger System

Level-1 Trigger System

• ALCT and CLCT find 2-D tracks

• TMB receives and correlates these tracks to make a 3-D Correlated LCT

• MPC receives up to 18 LCT’s from the different TMB’s and selects the best 3

• SR/SP receives the 3 LCT’s from the TMB

2004 Test Beam

• 100GeV muons for asynchronous run

• 100GeV pions for synchronous run (along with muons)

Angle vs. Trigger Mode

Pattern vs. Trigger Mode

NPH Pattern vs. Trigger Mode (for Andrey Pattern)

Conclusions

• Andrey Pattern does the best for higher nph patterns

• Keeps Efficiency high and ghost rates low