1. Neutrinos from BBfit
J. Brunner

2. Data selection (3N trigger)
01/02/07-25/05/07
25/05/07-04/12/07 Au
36.6 days
90.7 days
Ag-Au
10.5 days
29.8 days Ag
47.1 days
120.5 days
Adding Ag-Au data (~30%) decreases rates by 10-15%
whereas MC stays the same (produced with Au reference run)
Strasbourg
This presentation

3. Data Selection Data sample comparison : Strasbourg versus now
120.5 days
2.5 M muons
11.5 M muons
36.8 days

4. Event rates muons Data(1) neutrinos Basic cuts(2) 1.23 Hz 1.18 Hz
4.8/day
Single line
0.54 Hz
0.51 Hz
Multi line
0.69 Hz
0.67 Hz
1L upward
1501/day
1835/day
2.0/day
2L upward
657/day
894/day
2.8/day
Scaled with 1.2 for trigger bug (see analysis elog 125)
6 hits at least && track fit better than bright point fit

5. Zenith angles multi-line basic cuts
Good match MC-data MC truth shape well maintained
0.67Hz
0.69Hz
657/day
894/day
2.8/day

6. Zenith angles single-line basic cuts
Good match MC-data MC truth shape well maintained
0.51Hz
0.54Hz
1501/day
1835/day
2.0/day

7. Fit Quality Slight difference between data and atm. muon MC
Multi line fit
Slight difference between data and atm. muon MC
Not yet understood
Might also be related to atm. muon physics (hadronic model, composition)
Better agreement for neutrinos (see below)
Single line fit

8. Fit Quality for upward going tracks
Multi line fit
Single line fit
Cut for multi lines: 4.3
Purity better than 95%
Cut : 2.7 , ct>0.5
Purity better than 80%
PP?
0.36/day
0.78/day
0.70/day
0.45/day
0.005/day
0.07/day

9. Angular error for zenith angle
Mean values of log of zenith angle difference
muons
neutrinos
2.0º
2.1º
0.7º (15%)
0.7º (25%)
No ghost peak at 90 degree
Neutrino reconstruction not better than muon reconstruction
Cut gains factor 3 in precision for 15-25% subsample

10. Angular error for space angle
Mean values of log of space angle difference
muons
neutrinos
6.5º
8.9º
3.1º (15%)
4.4º (25%)
No ghost peak at 90 degree
Neutrino reconstruction not better than muon reconstruction
Cut gains factor 2 in precision for 15-25% subsample

11. Neutrino count : 155 / 167 days 01/02/07-25/05/07 25/05/07-04/12/07 Au
1L : 18
2L : 16
Ag-Au
1L : 3
2L : 4 Ag
1L : 21
2L : 20
1L : 36
2L : 78
Ag-Au runs contribute marginally (to be verified for other periods)
Strasbourg
This presentation

12. Zenith angles multi-lines
update
78 neutrinos
78 neutrinos
PP?

13. Zenith angles single-line
PP?
36 neutrinos
36 neutrinos

14. Bright neutrinos

15. Bright neutrinos

16. 10 lines analysis Data Dec 2007 – Apr 2008; Ag runs : 100 active days
Multi line
Single line
Use same cut: 4.3
Use same cuts: 2.7
costh > 0.5

17. 10 lines analysis
Data Dec 2007 – Apr 2008; Ag runs : 100 active days
Multi line
Single line
208 neutrino
88 neutrino
PP?

18. Bright neutrinos