1. Bug fix on km3 scattering tables First tests with new tables Jürgen Brunner

2. Bug signature (Maarten) Hit probability after km3 for hits from different origin (all MC truth) Should reproduce angular acceptance of PMT (inverted here) Ok for scattered light Hole between 0.8-1. for direct light Direct muon Direct e/m Scattered Muon Scattered e/m

3. Bug trace A. Heijboer: Analysis of km3 scattering tables –Old tables (~5 years) were found ok –New tables affected J.P. Ernenwein: Closer look into affected tables –10 PMT angular bins for direct light –5 PMT angular bins for scattered light –First bin for direct light contains often NaN –First bin corresponds to range 0.8-1.0 –Scattered light tables ok

4. Bug fix (JB) Function from hit package –hit-find_om_directions.f Last modified in 1997 How to calculate angle w.r.t. PMT –theta=h_theta_ch+acos(1.0-cos_theta_step*float(j-1)) Obtain sometimes –acos(-1.000001) Protection introduced –cosarg=max(-1.,min(1.,1.-cos_theta_step*float(j-1))) –theta=h_theta_ch+acos(cosarg) New release : km3 v3r6

5. Bug fix verification (Maarten) New Scattering tables created (Annarita) Hit probability for direct muons from a sample created with corrected table Red line: Genova parametrisation

6. Effect on neutrino analysis Use new production by C. Distefano (elog:336) Atm muons not modified (scaled Bugaev model) BBfit fit quality for 2008 multiline sample 41% more events with chi2<1.3 Data/MC ratio for neutrinos improves from 1.27 to 0.90

7. Effect on neutrino analysis Use new production by C. Distefano (elog:336) Atm muons not modified (scaled Bugaev model) BBfit fit quality for 2008 Tarot sample (nline>2) 58% more events with chi2<1.5 Data/MC ratio for neutrinos improves from 1.71 to 1.09

8. Update of public plots Several changes accumulated since public plots had been published first –PMT angular acceptance –Walk correction (data+MC) –NaN bug a)From water tank measurement b)From detailed simulation

9. Related public plot Antplot-Phys-2009-008 Several changes accumulated in the mean time –Bug fix, PMT angular acceptance, walk correction 582 ev 13 ev 494 ev Xc 599 ev 9 ev 638 ev Better data/MC agreement over whole angular range old new

10. Related public plot Antplot-Phys-2009-008 Same plot : Zoom into upward region 582 ev 13 ev 494 ev Xc 599 ev 9 ev 638 ev Better data/MC agreement over whole angular range new old

11. Related public plot Antplot-Phys-2009-008 Same data: Azimuth for upward part 582 ev 13 ev 494 ev Xc 599 ev 9 ev 638 ev new old

12. Effect on neutrino analysis BBfit fit quality for 2008 single line events 30% more events with chi2<0.8 Data/MC ratio for neutrinos degrades from 0.97 to 0.75

13. Related public plot Antplot-Phys-2009-009 Same list of changes as before –Bug fix, PMT angular acceptance, walk correction Chi2<1. 237 ev 21 ev 190 ev Xc Tuning of chi2 cut necessary to keep good purity old new Chi2<1. 243 ev 47 ev 225 ev

14. Related public plot Antplot-Phys-2009-009 Same list of changes as before –Bug fix, PMT angular acceptance, walk correction Chi2<1. 237 ev 21 ev 190 ev Xc Chi2<0.85 134 ev 14 ev 174 ev Tuning of chi2 cut necessary to keep good purity old new

15. Related public plot Antplot-Phys-2009-009 Same plot : Zoom into upward region 237 ev 21 ev 190 ev Xc 243 ev 47 ev 225 ev Data too high  ~ ok new old

16. Related public plot Antplot-Phys-2009-009 Same plot : Zoom into upward region 237 ev 21 ev 190 ev Xc 134 ev 14 ev 174 ev Data too high  data too low new old

17. Summary New km3 release with protection against NaNs in hit package New scattering tables produced (Annarita) New Neutrino production done (Carla) Effect studied and found as expected Recent updates and bug fixes do generally improve data/MC comparison