1. Jan 8 2004Cambridge Collaboration Meeting1 Pi/Mu Separation and Muon dE/dX Leo Jenner, UCL

2. Jan 8 2004Cambridge Collaboration Meeting2 In Brief… Pi/Mu separation runs at CalDet this year Pi/Mu dE/dX Plane efficiency Pion contamination of muon sample

3. Jan 8 2004Cambridge Collaboration Meeting3  Test beam to CERN East Hall contains electrons, pions, muons, kaons, protons, deuterons  Pions usually shower but occasionally look identical to muons  Special Cerenkov runs: over and under pion threshold 1.8 GeV

4. Jan 8 2004Cambridge Collaboration Meeting4 Before and after collimators from Turtle Lph: 49/50

5. Jan 8 2004Cambridge Collaboration Meeting5 30036 of 36310 events fired neither cerenkov

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7. Jan 8 2004Cambridge Collaboration Meeting7  Range > 40 to remove electrons  Both(muons): 3176, 3not1(pions): 806, 1not3: 427, neither: 4189  Cerenkov 3: 85% efficient, good agreement with MK

8. Jan 8 2004Cambridge Collaboration Meeting8  Cov cut doesn’t get all PS muons and eat lots of real muons  Also try correcting for plane efficiencies

9. Jan 8 2004Cambridge Collaboration Meeting9 Plane 2 and 6 hit… was plane 4 hit? Blue: Plane 2 and 4 hit… was plane 0 hit?

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12. Jan 8 2004Cambridge Collaboration Meeting12  48 < Range < 57  Scaled by plane efficiencies

13. Jan 8 2004Cambridge Collaboration Meeting13 Pion dE/dX Lph=53 Magnets deviated?

14. Jan 8 2004Cambridge Collaboration Meeting14 Sum of deposited energy 60 keV / sigcorr ADC 33.96 MeV deposited per plane (averaged along entire track) 27.96 MeV / plane expected from Bethe- Bloch (25.86 + 2.1 + 0.0031)

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16. Jan 8 2004Cambridge Collaboration Meeting16 15% back to pions, 2.25% to muons Far more muons than expected

17. Jan 8 2004Cambridge Collaboration Meeting17 Conclusion Many PS muons Cov 3 about 85% efficient CalDet plane efficiency about 88% Range cut much more successful than Cov cut Focussing magnets may have deviated 60 keV / sigcorr ADC Many more muons than expected w.r.t. pions

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