ND Data/MC Comparisons

1. ND Data/MC Comparisons Patricia Vahle University College London Fermilab Collaboration Meeting October, 2005 Outline: I. Things (I think) I understand II. Things I don’t understand

2. Cuts Applied Beam Quality Cuts tor101 > = 0.1e12 pot/spill tortgt > = 0.1e12 pot/spill horizontal beam width < = 2.9 mm vertical beam width < = 2.9 -2 mm < = horizontal beam position at target < = 0 mm 0 mm < = vertical beam position at target < = 2 mm closest beam monitoring record witin 2 sec. of snarl time horn current > = 50 A

3. Cuts Applied ND Data Quality Cuts event vertex in "The Pittsburg Fid. Region" event vertex x position < 2.4 m 0.6 m < event vertex z position < 3.56 m 0.3 m < event vertex u position < 1.8 m -1.8 m < event vertex v position < -0.3 m event vertex 0.8 m away from coil hole trk.fit.pass==1 track fit chi2/NDF < 10 difference in planes between the u vertex and v vertex < 6 planes number of tracks == 1 absolute value of error in (q/p) divided by q/p < .2 if muon momentum is obtained by curvature (not a stopper). no other event with vertex time within 50 ns of event in question 90% of shower energy must be in fully instrumented planes muon charge < 1 track vertex z position > 0.6 m

4. Ely Energy Distributions • Black—LE • Red—pME • Blue—pHE • Solid—data • Bands—MC with beam sys. errors Data and MC in pME and pHE beams don’t match!

5. Ely MC Old GMINOS executable, no target offsets to wfluk routine Black—Old ME MC Pink—ME flux, tgtshift=0 All fixed in R1.18 MC Only affects ME and HE

6. Eν Distributions Now • Black—LE10 • Red—pME • Blue—pHE • Solid—data • Bands—MC with beam sys. errors Much Better!

7. Events Accepted

8. Eν Distributions Now LE10 Black—Data Red—MC Blue—true NC Scaled to POT • There’s still an offset… • Difference in means: • LE10—1.9% • ME—5.8% • HE—4.5% HE ME

9. Eμ Distributions Now LE10 Black—Data Red—MC Scaled to POT HE ME More low E muons in data More high E muons in MC

10. Eshw Distributions Now LE10 Black—Data Red—MC Scaled to POT HE ME

11. Lin. vs. Deweighted Eshw LE10 • Default Shower energy Is now the “deweighted” version • Reco E_nu looks better using this version of the shower energy! Black—Data Red—MC HE ME Scaled to POT

12. Lin. vs. Deweighted Eshw LE10 Black—Data Red—MC But. . . There’s a problem with the deweighted shower energy HE ME Scaled to POT Differences between the two methods suggests an underlying data/MC difference

13. Lin. vs. Deweighted Eshw Deweighted shw. energy smaller than linear shw. energy pME beam Data MC Deweighted shw. energy bigger than linear shw. energy

14. Track Strip Pulseheight LE10 Black—Data Red—MC HE ME Scaled to # Events

15. Shower Strip Pulseheight LE10 Black—Data Red—MC Excess of <1PE hits in Data showers 1 PE ~= 100 sigcor HE ME Scaled to # Events

16. Shower strip times LE10 Black—Data Red—MC ME HE Scaled to # Events

17. Shower Strip times Black—Data Red—MC For shower hits > 2.5 pe LE10 ME HE Scaled to # Events

18. Number of Shower Strips Black—Data Red—MC LE10 ME HE Scaled to # Events

19. Number of Shower Strips LE10 Black—Data Red—MC For shower hits > 2.5 pe • Data and MC means agree within 1 strip • Mean in data > mean from MC • Few entries in the zero bin ME HE Scaled to # Events

20. Ave Shower pulseheight LE10 Black—Data Red—MC ME HE Scaled to # Events

21. Ave Shower pulseheight LE10 Black—Data Red—MC Only counting hits > 2.5 pe • Data and MC means differ by < 1pe • Data bigger than MC ME HE Scaled to # Events

22. Max. Shower pulseheight LE10 Black—Data Red—MC Few pe differences in means Data has bigger max shower pulse height than MC ME HE Scaled to # Events

23. Total Shower pulseheight LE10 Black—Data Red—MC • Data mean is bigger than MC mean • But in GeV, Data<MC? • Needs a closer look at sigcor->sigmap->mip conversion X10^3 HE ME Scaled to # Events X10^3 X10^3

24. Total Shower pulseheight LE10 Black—Data Red—MC Only counting hits > 2.5 pe X10^3 HE ME Scaled to # Events X10^3 X10^3

25. Clean Timing Cut Black—Data Red—MC LE10 • Time between accepted event and the event closest in time • Designed to get rid of “runt events” • Used to cut out first bin (<50 ns) • Intensity dependent HE ME Scaled to POT

26. Runt Events U (m) Time (ns) • Red—accepted event • Green—hits within 60 ns of event, in same slice but not in event • Pink—hits within 60 ns of event, but not in same slice • Blue—all hits from the slice that contains pink Z (m) Z (m) V (m) Z (m) Time (ns)

27. Event Timing LE10 Black—Data Red—MC Higher intensity in MC means The clean timing cut throws away many more good events in the MC than in data HE ME

28. Event Timing LE10 Black—Data Red—MC Events in data last longer HE ME

29. Event Timing LE10 Black—Data Red—MC Only considering hits > 2.5 pe HE ME

30. Shower E vs. Duration MC LE10 data ME data MC Time duration (ns) Lower energy showers last longer MC HE data Reco. E shw (GeV)

31. Cut on time duration LE10 Require time duration<200 ns Black—Data Red—MC Scaled to POT • There’s still an offset… • Difference in means: • LE10—1.2% • ME—5.2% • HE—3.5% HE ME

32. Summary • Bug found in Ely vintage MC. Old ME and HE spectra from MC do not have wfluk reweighting • New MC looks better, but there’s still an offset • Using deweighted shower energy calculation mitigates the shift, but is this masking an underlying difference? • Excess of <1 pe hits in showers • Other low level shower quantities don’t look crazy • Timing quantities differ between data and MC • Time between events—different intensities • Time length of events • Future investigations • Higher levels of calibration chain? • Different slicing parameters?