1. Control plots at hadron level from official MC production
Marek Taševský, V. Kůs, O. Kepka
(Institute of Physics, Academy of Sciences, Prague)
H. Bansil, P. Newman
(University of Birmingham)
Prague - 11/

2. Statistics available in official samples
Data go to gap ~ 7 (see previous slide). Statistics of official ND samples insufficient, information
on the large gaps is missing. A filter based on the gap distribution is needed.

3. HERWIG ND weighted

4. HERWIG++ 2.6 ND weighted: sums

5. HERWIG++ 2.6 ND unweighted

6. HERWIG++ 2.6 ND unweighted: sums

7. HERWIG++ 2.6 ND weighted, w<8E4
Remove weights w>8E4
(loss smaller than 1 per-mille and concentrated
in very first Gap bin)
Get smoother Pt and Eta spectra

8. HERWIG++2.6 ND weighted:sums,w<8E4
Remove weights w>8E4:
Get smoother Pt and Eta spectra

9. HERWIG++2.6 ND unweighted:sums,w<8E4

10. HERWIG++2.6 SD1 weighted

11. HERWIG++2.6 SD1 weighted: sums

12. HERWIG++2.6 SD1 unweighted
Note: JZ0W corrupted

13. HERWIG++2.6 SD1 unweighted: sums
Note: JZ0W corrupted

14. HERWIG++2.6 SD2 weighted

15. HERWIG++2.6 SD2 weighted: sums

16. HERWIG++2.6 SD2 unweighted
Note: JZ0W corrupted

17. HERWIG++2.6 SD2 unweighted: sums
Note: JZ0W corrupted

18. PYTHIA 8 ND weighted

19. PYTHIA 8 ND weighted: sums

20. PYTHIA 8 ND unweighted

21. PYTHIA 8 ND unweighted: sums

22. PYTHIA 8 ND unweighted: sums

23. PYTHIA 8 ND weighted: w<2E5
Remove weights w>2E5
(loss smaller than 2 per-mille and concentrated
in very first Gap bin)
Get smoother Pt and Eta spectra

24. PYTHIA 8 ND weighted: sums, w<2E5
Remove weights w>2E5
Get smoother Pt and Eta spectra

25. PYTHIA 8 ND unweighted: sums, w<2E5

26. PYTHIA 8 ND unweighted: sums, w<2E5

27. PYTHIA 8 SD weighted

28. PYTHIA 8 SD weighted: sums

29. PYTHIA 8 SD unweighted

30. PYTHIA 8 SD unweighted: sums

31. PYTHIA 8 SD unweighted: sums

32. PYTHIA 8 DD weighted

33. PYTHIA 8 DD weighted: sums

34. PYTHIA 8 DD unweighted

35. PYTHIA 8 DD unweighted: sums

36. PYTHIA 8 DD unweighted: sums

37. Preliminary findings 1. HW26SD1_JZ0W and HW26SD2_JZ0W corrupted
2. JZxW give smoother Etajet1 and Ptjet1 spectra
3. JZ0Ws are problematic:
a) only few events survive Etjet2>12 GeV cut. From 400k of each sample we have:
HW26ND: 1098, HW26SD: 0, PY8ND: 11973, PY8SD: 12773, PY8DD: 12514
- how many do we have after the detector-level selection Etjet1>30, Etjet2>20???
b) The sum JZ0W+JZ1W+JZ2W doesn’t match the x-section of the weighted samples
The culprit is JZ0W: but what’s wrongly calculated??
- i) weight=1.0 – probably OK
- ii) x-section?
- iii) Filtering efficiency?
4. Due to large weights, Ptjet1 and Etajet1 spectra aren’t smooth in weighted samples.
If events with huge weights are removed, the spectra get smoother. But the MC
predictions in the very first bin of the Gap distribution lower by a visible manner.
This will be followed up after the reco D3PDS are produced and samples after the
detector-level cuts Etjet1>30, Etjet2>20 GeV are created.