1. Measurement of the Neutrino Mass hierarchy in the deep sea
J. Brunner 

2. Matter effects & Mass Hierarchy
Solar Neutrinos : Matter effects inside sun
 m2 > m1
Matter effects in Earth (not yet measured !)
 m3 >< m1,m2
Normal Hierarchy Inverted Hierarchy

3. Matter effects & Mass Hierarchy
e see additional potential due to W-exchange in +e  +e scattering
Illustration for constant electron density ne
At resonant energy 13 maximal
A changes sign with ne via  / 
A changes sign with m2  mass hierarchy !

4. Example Earth Matter Effect : P(µe)
Resonance energy Earth mantle : 6-7 GeV
GLOBES NH IH
cos = 0.6
Baseline = 7645 km
Inclination = 36.9˚

5. Example Earth Matter Effect : P(µµ)
Resonance energy Earth mantle : 6-7 GeV NH IH
GLOBES
cos = 0.6
Baseline = 7645 km
Inclination = 36.9˚

6. Sensitivity Calculation
Fit of event count in Energy-Zenith space
Color code : bin-by-bin significance of hierarchy difference
Oscillation parameter fixed
Oscillation parameter fitted
W. Winter : arXiv:

7. Dense Mton detector with KM3Net design
ORCA
Dense Mton detector with KM3Net design
Oscillation Research with Cosmics in the Abyss
Less than 20 MEuro with current KM3Net technology

8. PINGU : Sensitivity combined

9. ORCA Sensitivity  Comparable or Better !
6 years
Cascades
Muons
No particle ID
Cascades better than Muons
Combination improves sensitivity
by about a factor 2
Muons only

10. Huber : Sensitivity over time
ArXiv:

11. A neutrino beam towards orca

12. Why consider Beams ? PINGU / ORCA Motivations Neutrino Beams
Fast : Construction within few years
Significant measurement after few years
Stay within low budget
Neutrino Beams
Expensive & long(er) Timescale
 counter intuitive
Matter effects with Atmospheric Nu’s
More challenging than originally hoped for
Beam allows for complementary measurement
Easier to motivate if pointing towards an existing detector
Maybe possible in “parasitic mode”

13. Why consider Beams ?
Recently : change of paradigm for European LBL program
Opens new, so far neglected options

14. Optimal Baseline ?
For L>2000km the oscillation probabilities are always well separated for both MH hypotheses
To find optimal baseline calculate event rates
N ~ 1/L2
N ~ E (cross section)
Fixed beam profile
ORCA detector response NH IH

15. Optimal Baseline
L=2600km maximizes the difference in event rates between two MH hypotheses
Event rate difference
NH - IH

16. Proton Accelerator Complex Protvino
Presentation S. Ivanov (IHEP) on CERN  Talk Wednesday

17. Proton Accelerator Complex Protvino
Presentation S. Ivanov (IHEP) on CERN

19. Protvino – ORCA
Baseline 2588km ; beam inclination : 11.7˚ (cos = 0.2)
Deepest point 134km : 3.3 g/cm3

20. SKAT bubble chamber Shielding SKAT target Decay pipe p 55m focus 140m
Courtesy: R. Nahnhauer

21. Beam parametrisation (1988)
Neutrino Focus
Anti-Neutrino Focus
Scaling to ANTARES site
(0.245/2600)2
Z. Phys. C 40 (1988) 487

22. Off-Axis Beam : suppress HE tail
Beam optimisation still to be done
Off-axis or combination on-axis/off-axis might be favorable

23. Event rates - Signal e CC µ CC NH 10927 +/- 24 NH 1621 +/- 255
Event numbers for p.o.t.s (3 years NOVA beam)
20  statistical separation of both Mass Hierarchy hypotheses from signal
10000 muon events for beam normalisation
3.5% separation between MH hypotheses
Other contributions: : /- 13 ; /- 8 ; NC : 4732
NH /- 24
NH /- 255
IH /- 43
e CC
µ CC
IH /- 100

24. Event rates – All Flavours & Mis-ID
Event numbers for pots
9-18% difference for NH/IH
7  statistical separation of MH hypotheses
Can allow for 3-4 % syst. uncertainty
No requirement of energy reconstruction
tracks
cascades
NH /- 45
NH /- 200
IH /- 15
IH /- 80

25. Flavour identification & Neutrino Energy
Need to separate “tracks” from “cascades”
Villars : C2GT project (F. Dydak)
CERN to Gulf of Taranto

26. Flavour identification
Villars : C2GT project (F. Dydak)
Clean separation of µ CC and e CC at 0.8 GeV
OM spacing 3m

28. Dense detector 3x3 with cone display
Electron-Neutrino Event, C-Cone clearly visible
E = 5 GeV ; Ee= 4 GeV
50nsec
100 nsec

29. Synergies between potential Sites
Protvino
11.0˚
4.1˚
Modane
2393km
13.6˚
Antares
2588km
Gran Sasso
2189km
Nemo
2574km

30. Conclusion Preliminary Performance Figures of ORCA encouraging
Mass hierarchy measurement in the deep sea possible
Upgraded proton accelerator at Protvino well suited for LBL towards Mediterranean Sea
Needed : 1021 p.o.t. within few years
Perfect subject for Russian Mega-Science program
Synergy with Underground Labs in the same beam
Complementary to measurement with atmospheric 
Complementary between ORCA / PINGU
High Significance determination of Mass Hierarchy

31. Possible Timescale
: Finalize optimization work for both options
Currently active groups : CPPM, APC, ECAP (Erlangen)
 Publish comprehensive document
~2016 : Planning “Phase II” of KM3Net
Parallel : Contact with Russian partners, LoI ?
First encouraging contact 08/2013 (Y. Kudenko, INR)
Start contact with Modane project(s) (ex LBNO)
First discussion 08/2013

32. Backup

33. Neutrinos from Beams Narrow band beam 6-9 GeV 1020 p.o.t.
Eliminate ambiguities
Improve mass hierarchy sensitivity
arXiv:
Narrow band beam 6-9 GeV
1020 p.o.t.

34. P(µ µ) cos = 0.1 Baseline = 1274 km NH Inclination = 5.7˚ IH
GLOBES
cos = 0.1
Baseline = 1274 km
Inclination = 5.7˚ NH IH

35. P(µ µ) cos = 0.2 Baseline = 2548 km NH Inclination = 11.5˚ IH
GLOBES
cos = 0.2
Baseline = 2548 km
Inclination = 11.5˚ NH IH

36. P(µ µ) cos = 0.3 Baseline = 3823 km NH Inclination = 17.4˚ IH
GLOBES
cos = 0.3
Baseline = 3823 km
Inclination = 17.4˚ NH IH

37. P(µ µ) cos = 0.4 Baseline = 5097 km NH Inclination = 23.6˚ IH
GLOBES
cos = 0.4
Baseline = 5097 km
Inclination = 23.6˚ NH IH

38. P(µ µ) cos = 0.5 Baseline = 6371 km NH Inclination = 30.0˚ IH
GLOBES
cos = 0.5
Baseline = 6371 km
Inclination = 30.0˚ NH IH

39. P(µ µ) cos = 0.6 Baseline = 7645 km NH Inclination = 36.9˚ IH
GLOBES
cos = 0.6
Baseline = 7645 km
Inclination = 36.9˚ NH IH

40. P(µ µ) cos = 0.7 Baseline = 8919 km NH Inclination = 44.4˚ IH
GLOBES
cos = 0.7
Baseline = 8919 km
Inclination = 44.4˚ NH IH

41. P(µ µ) cos = 0.8 Baseline = 10194 km NH Inclination = 53.1˚ IH
GLOBES
cos = 0.8
Baseline = km
Inclination = 53.1˚ NH IH

42. P(µ µ) cos = 0.9 Baseline = 11468 km NH Inclination = 64.2˚ IH
GLOBES
Beam to IceCube
cos = 0.9
Baseline = km
Inclination = 64.2˚ NH IH

43. P(µ µ) cos = 1.0 Baseline = 12742 km NH Inclination = 90.0˚ IH
GLOBES
cos = 1.0
Baseline = km
Inclination = 90.0˚ NH IH

44. Counting Muons from Beam Neutrinos
Optimal Beamline : km
Favoured Option:
FermiLab – KM3Net site in Mediterranean Sea
1300 versus 950 events for both mass hierarchy hypotheses in Mton underwater detector (ORCA)
 Inverse approach : Counting “Electrons”
arXiv:

45. P(µe) cos = 0.1 Baseline = 1274 km NH Inclination = 5.7˚ IH GLOBES
(CP-phase varied in steps of 30˚)
cos = 0.1
Baseline = 1274 km
Inclination = 5.7˚ NH IH

46. P(µe) cos = 0.2 Baseline = 2548 km NH Inclination = 11.5˚ IH
GLOBES
cos = 0.2
Baseline = 2548 km
Inclination = 11.5˚ NH IH

47. P(µe) cos = 0.3 Baseline = 3823 km NH Inclination = 17.4˚ IH
GLOBES
cos = 0.3
Baseline = 3823 km
Inclination = 17.4˚ NH IH

48. P(µe) cos = 0.4 Baseline = 5097 km NH Inclination = 23.6˚ IH
GLOBES
cos = 0.4
Baseline = 5097 km
Inclination = 23.6˚ NH IH

49. P(µe) cos = 0.5 Baseline = 6371 km NH Inclination = 30.0˚ IH
GLOBES
cos = 0.5
Baseline = 6371 km
Inclination = 30.0˚ NH IH

50. P(µe) cos = 0.6 Baseline = 7645 km NH Inclination = 36.9˚ IH
GLOBES
cos = 0.6
Baseline = 7645 km
Inclination = 36.9˚ NH IH

51. P(µe) cos = 0.7 Baseline = 8919 km NH Inclination = 44.4˚ IH
GLOBES
cos = 0.7
Baseline = 8919 km
Inclination = 44.4˚ NH IH

52. P(µe) cos = 0.8 Baseline = 10194 km NH Inclination = 53.1˚ IH
GLOBES
cos = 0.8
Baseline = km
Inclination = 53.1˚ NH IH

53. P(µe) cos = 0.9 Baseline = 11468 km NH Inclination = 64.2˚ IH
GLOBES
Beam to IceCube
cos = 0.9
Baseline = km
Inclination = 64.2˚ NH IH

54. P(µe) cos = 1.0 Baseline = 12742 km NH Inclination = 90.0˚ IH
GLOBES
cos = 1.0
Baseline = km
Inclination = 90.0˚ NH IH

55. Oscillation parameters
Taken from Global Fit (Fogli et al.) for both hierarchy options
CP phase left free

56. Neutrino Cross sections
Simple parton scaling assumed (QE, Res. ignored) Flavour universality m threshold NC approximation

57. Neutrino Cross sections
Simple parton scaling assumed (QE, Res. ignored) Flavour universality m threshold NC approximation
NC, CC: e µ 
Solid : neutrino , dashed : antineutrino

58. Event rates
Here : no flavour misidentification
CC Rates
NC Rates

59. Event rates Include Background and Flavour tagging Total Background :
Total Event Rate :

60. Flavour identification
Misidentification probability :
assume same for both directions
50% at 2 GeV  random ; 20% at 5 GeV ; 10% at GeV

61. V. Ludwig (ECAP)

62. Systematic Uncertainties
Detector Response
Water parameters
Extensively studied in ANTARES
Neutrino flux
Can be monitored with muon events
Neutrino Cross Section
Ongoing and planned short baseline Experiments
Oscillation parameters
ORCA with atmospheric neutrinos