Cedar and pre-Daikon Validation

1. Cedar and pre-Daikon Validation • CC PID parameter based CC sample selections with Birch, Cedar, Carrot and pre-Daikon. • Cedar validation for use with QEL analyses. • Pre-Daikon validation for use with QEL analyses. Mark Dorman UCL / RAL ND Phone Meeting (1st Nov.)

2. File Processing • Any comparisons of Birch and Cedar reconstruction use Carrot MC. • Any comparisons of Carrot and pre-Daikon MC use Birch reconstruction. • Anything processed with Birch reconstruction has had the energy and steel density corrections applied. • Anything processed with Cedar reconstruction does not. • Any Carrot MC files have been reweighted with SKZP2 and MODBYRS3. • Any pre-Daikon MC files have only been reweighted with SKZP2. • For MC validation have used Carrot singles files and pre-Daikon 'Pass 4' set. • My usual pre-selection cuts have been applied (see backup slide for details). • CC samples have been selected from Birch and Cedar reconstructed files using different PDFs and PID cuts – see following slides for details.

3. CC PDFs With Birch and Cedar • Some shape differences. • Track PH fraction shifts up for CC and NC due to new track finder. • Is this because better tracking into spectrometer gives longer (and hence larger PH) tracks in Cedar? NB: all histograms normalised to unit area.

4. CC PID With Birch and Cedar

5. CC Samples With Birch and Cedar • Scan over PID cut shows how the differences in the PDFs and PID manifest themselves in the selected CC sample. • Nominal cut at -0.1 does different things in Birch and Cedar. • Cutting Birch events at -0.1 and Cedar events at -0.085 gives similar CC sample efficiencies and purities. • Will use these values for the validation analysis.

6. CC PDFs With Carrot and pre-Daikon • Shapes look very similar but also limited statistics for pre-Daikon. • Will continue to use nominal PID cut at -0.1 to select CC samples for validation analysis. NB: all histograms normalised to unit area.

7. Conclusions Part 1 • Slight differences in the CC PDF shapes in Cedar lead to a different CC PID distribution. The difference in the PID distribution in turn effects the efficiency and purity of the CC sample selected with the nominal cut (between Birch and Cedar). • Have tried to change the cut on the Cedar CC PID to give a similar CC sample efficiency. I can now apply these different cuts to the data and MC CC PID values when performing Cedar validation. • Have looked at CC PDF shapes with Birch-Carrot and Birch-preDaikon MC and have seen no big differences. Will continue to use Birch-Carrot CC PDFs with the nominal cut to select CC events for pre-Daikon validation.

8. Cedar Validation – CC-like Neutrino Energy • Good general agreement between shapes of energy spectra. • Excess of events in Cedar data and MC as compared to Birch (above 1 GeV). • MC excess ~5-10%. Data excess ~10-20%. • Data/MC double ratio fairly flat but slightly larger data/MC disagreement in Cedar.

9. Cedar Validation – QEL-Enriched Neutrino Energy • Slight shift to higher neutrino energies can be seen for the Cedar QEL-enriched events. • Excess of events in Cedar data and MC as compared to Birch (above 1 GeV). • MC excess ~5-10%. Data excess ~10-20%. • Data/MC double ratio fairly flat but slightly larger data/MC disagreement in Cedar.

10. Cedar Validation – CC-like Shower Energy • Good general agreement between shapes of energy spectra. • Excess of events in Cedar data and MC as compared to Birch. • MC excess ~5-10%. Data excess ~15%. • Data/MC double ratio fairly flat but slightly larger data/MC disagreement in Cedar.

11. Conclusions Part 2 • I see an excess of events with Cedar reconstruction as compared to Birch. • Seems reasonable given that I require a track for inclusion in these samples and (I think) Cedar reconstructs more tracks (can have 5 plane tracks now). • There is a slight shift towards higher neutrino energies for high neutrino energy events in Cedar. • This could make sense given the improvements made in tracking into the spectrometer in Cedar (leading to longer and hence more energetic tracks). • The shower energy distributions look consistent with a similar excess of Cedar events and there is no energy dependant shape difference introduced by Cedar. • Have looked at other distributions – don't see any QEL analysis show stoppers in moving to Cedar (and the old problems seen in Birch are still present).

12. Pre-Daikon Validation – Neutrino Energy • Reasonable agreement in shape but with slight excess of events in Carrot. CC-like Ehad < 250 MeV CC-like • Similar story for low hadronic energy (QEL enriched) sample. Expected to see more events here with pre-Daikon given that INTRANUKE changes should remove some of the shower energy on average.

13. Pre-Daikon Validation – Shower Energy • Don't see much change in the shower energy between Carrot and pre-Daikon. Expected an excess of pre-Daikon (rather than Carrot) at low shower energies due to the new INTRANUKE implementation.

14. Pre-Daikon Validation – Muon Angle • Generally reasonable agreement but with 'flattening off' of peak in pre-Daikon MC. Ehad < 250 MeV CC-like CC-like • Reasonable agreement and with possibly better data/MC shape agreement for low Ehad sample with pre-Daikon.

15. Conclusions Part 3 • Have had a brief look at pre-Daikon MC as compared to Carrot singles and don't see anything ridiculous. It is too early to say much more but looks like there will be some interesting effects. • Generally need more time and more MC to be able to really find and understand the changes when moving from Carrot to Daikon. • Have not seen any QEL analysis show stoppers in what Carrot/Daikon comparisons I have looked at so far. • Overall I think both Cedar and Daikon are validated in the sense that I can process the files and perform studies. • I am happy for the move to Cedar to happen and have not seen anything dramatically wrong with Daikon but would like more time and statistics to be sure.

16. Backup Slides

17. Pre-Selection Cuts • Pre-selection cuts differ (slightly) from standard CC analysis: • Data must pass standard beam quality cuts and the special horn current runs are excluded. Event has 1 well reconstructed track and is in the 'Pittsburgh' fiducial volume If muon momentum is measured from curvature then the fractional error on this measurement is not more than 30% Zero or negative muon charge sign (anti-neutrino cut) Track starts at least 0.5m inside the detector (rock muon cut) Either there is no event within 50ns of the current event or the current event has at least 95% of the PH of itself and the nearest event (runt event cut)