Pi/Mu Separation and Muon dE/dX

Jan 8 2004 Cambridge Collaboration Meeting

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Pi/Mu Separation and Muon dE/dX

Leo Jenner, UCL

Jan 8 2004 Cambridge Collaboration Meeting

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In Brief…

• Pi/Mu separation runs at CalDet this year

• Pi/Mu dE/dX

• Plane efficiency

• Pion contamination of muon sample

Jan 8 2004 Cambridge Collaboration Meeting

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Test beam to CERN East Hall contains electrons, pions, muons, kaons, protons, deuteronsPions usually shower but occasionally look identical to muonsSpecial Cerenkov runs: over and under pion threshold

1.8 GeV

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Before and after collimators from Turtle

Lph: 49/50

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30036 of 36310 events fired neither cerenkov

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Range > 40 to remove electrons

Both(muons): 3176, 3not1(pions): 806, 1not3: 427, neither: 4189

Cerenkov 3: 85% efficient, good agreement with MK

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Cov cut doesn’t get all PS muons and eat lots of real muons

Also try correcting for plane efficiencies

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Plane 2 and 6 hit… was plane 4 hit?

Blue: Plane 2 and 4 hit… was plane 0 hit?

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48 < Range < 57

Scaled by plane efficiencies

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Pion dE/dX

Lph=53

Magnets deviated?

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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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15% back to pions, 2.25% to muons

Far more muons than expected

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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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