1. Muon Decay Experiment Levi Neukirch UNL CROP Saturday Oct. 14, 2006

2. Oct. 14, 2006Muon Decay Experiment2 Muons Muons are unstable leptons Muons are unstable leptons Average lifetime t ave = 2.20 µs * Average lifetime t ave = 2.20 µs * µ -  e - + ν e + ν µ µ -  e - + ν e + ν µ ¯ * Introduction to Nuclear Physics. Kenneth Krane. Wiley & Sons. 1988 e-e-e-e- µ-µ-µ-µ- τ-τ-τ-τ- νeνeνeνe νµνµνµνµ ντντντντ

3. Oct. 14, 2006Muon Decay Experiment3 Experimental Goal Measure muon lifetime Measure muon lifetime –Build a thick detector –Write Labview software to detect muon decay signatures –Analyze data and calculate average muon lifetime

4. Oct. 14, 2006Muon Decay Experiment4 Apparatus 4” thick scintillator plate 4” thick scintillator plate Trigger detector Trigger detector Veto detector Veto detector

5. Oct. 14, 2006Muon Decay Experiment5 Apparatus Why this setup? Why this setup? µ-µ- e-e- Signal on Ch. 1 1 st Signal on Ch. 2 2 nd Signal on Ch. 2 Remember: µ -  e - + ν e + ν µ _ No Signal on Ch. 3

6. Oct. 14, 2006Muon Decay Experiment6 Apparatus

7. Oct. 14, 2006Muon Decay Experiment7 Software Labview code Labview code –Data collection –Data analysis Dedicated to muon decay analysis Dedicated to muon decay analysis

8. Oct. 14, 2006Muon Decay Experiment8 Software: Collection Sets coincidence criteria Sets coincidence criteria Writes data to.txt file Writes data to.txt file

9. Oct. 14, 2006Muon Decay Experiment9 Software: Analysis Reads.txt files Reads.txt files Computes lifetimes Computes lifetimes Writes.xls (MS Excel) histogram file Writes.xls (MS Excel) histogram file Displays decay time histogram Displays decay time histogram

10. Oct. 14, 2006Muon Decay Experiment10 Software

11. Oct. 14, 2006Muon Decay Experiment11 Data Analysis A = A 0 exp[-λt] (1) A = A 0 exp[-λt] (1) t 1/2 = ln(2)/λ (2) t 1/2 = ln(2)/λ (2) t ave = t 1/2 / ln(2) = ln(2)/λ/ln(2)(3) t ave = t 1/2 / ln(2) = ln(2)/λ/ln(2)(3) t ave = 1/λ(4) t ave = 1/λ(4)

12. Oct. 14, 2006Muon Decay Experiment12 Data Analysis 2857 Events Numerical mean = 2.125 µs

13. Oct. 14, 2006Muon Decay Experiment13 Data Analysis A = A 0 exp[-λt](1) λ = 0.00046 s -1

14. Oct. 14, 2006Muon Decay Experiment14 Data Analysis t 1/2 = ln(2)/λ t 1/2 = ln(2)/λ t ave = t 1/2 / ln(2) t ave = t 1/2 / ln(2) t ave = [ln(2)/0.00046 s -1 ]/ln2 = 1/0.00046 s -1 = 1/0.00046 s -1 t ave = 2.174 µs

15. Oct. 14, 2006Muon Decay Experiment15 Data Analysis (2.174µs - 2.20µs)/(2.20µs) = (2.174µs - 2.20µs)/(2.20µs) = 1.2% difference Run # of Events t ave % Error 11780 2.176 µs 1.1 % 22289 2.130 µs 3.2 % 32857 2.174 µs 1.2 %

16. Oct. 14, 2006Muon Decay Experiment16 Acknowledgements Thanks to: Prof. Dan Claes Prof. Dan Claes Prof. Greg Snow Prof. Greg Snow Prof. Herman Batelaan Prof. Herman Batelaan Jason Keller Jason Keller