1. ORCA proposed public plots
January 2013

2. Detector

3. Simulation chain

4. Effective volume?
Zenith angle.

5. Apostolos ?
Space angle.

6. Muon energy resolution
BBfit - vertex contained - timing
Energy from range
Quantiles 16%-84% (~rms)
Function of muon energy

7. Update on mass hierarchy computations
Aart Heijboer
(with many thanks to Anselmo, Juergen, Spyros)

8. New plots... cos(q) = -1 dominant source of uncertainty
… like Fig 2 of Akhmedov et al …. but with error bands
dominant
source of
uncertainty

9. New plots... cos(q) = -0.8
source of
uncertainty

10. New plots... cos(q) = -0.6
source of
uncertainty

11. New plots... cos(q) = -0.4
source of
uncertainty

12. Effect of 1s parameter uncertainties on relative rate (NH)
Dm2 small
Dm2 large
q23
cos(zenith)
negligible
log(E/GeV)
q13
q12
negligible

13. Analysis dealing with model uncertainties
(optimally)
For determining the MH, the angles and mass differences are nuisance parameters. → use ratio of maximum likelihoods
maximum-likelihood estimates for the Dm2's and angles using both data and constraints from global fit.
nb: constraints are different for H=IH and H=NH
So this means fitting the mixing parameters to the data, twice, before
computing the test-statistic.
To save some time, I fix Dm21 and q21 in the fit to the global-fit central values.
( Fit takes ~1 minute / toy )

14. Summary of assumptions for toy analysis
Acceptance: 1Mton of 36x 20 OMs
require 15 hits and n in volume.
Zenith angle resolution: use true muon
direction (from gen. level MC).
Energy resolution: assume 20%
No backgrounds / flavor mis-id / systematics etc.
toys:
pick a true hierarchy Htrue
vary model parameters within allowed range(Htrue)
(assuming no correlations, since they are not published(?))
and generate toy experiment
constraint fit of 3 non-fixed model parameters to experiment assuming both NH and IH → two sets of parameters
likelihood ratio

15. Results of parameter fit
1 Mton*year ( NHtrue, NHfit )
parameter central sigma sigma sigma
name now now Mtonyr Mtonyr
delta_m2_large e e e e-5
theta23 (deg)
theta13 (deg)
Fit working well.
Good sensitivity
to Dm2large & q23 !
nb: parameter fit is for one assumed MH

16. Mass hierarchy significance
– NH
– IH

17. Mass hierarchy significance
– NH
– IH

18. Earth density profile.
50 km limit shift – no impact
assumption of the flat density profile – no impact (p=0.999 at 3 σ)
reducing the overall density by 10% - p=0.996
density is increased by 10% - p=0.872
varying the overall density factor by 1% - no effect
Second the Earth density profile was studied.
50km layers shift has no impact on the p-value
assumption of the flat density profile – no impact as well
reducing the overall density by 10% no impact
increasing the density by the same value – small impact
and finally varying the overall density factor by 1% - no impact
4 different biases were introduced which are basically larger than known uncertainties or even unphysical.
PAUSE
introduced biases are larger than the known uncertainties or even unphysical