Neutrino Oscillation Tomography

Transcription

1 1 Neutrino Oscillation Tomography (and Neutrino Absorption Tomography) (and Neutrino Parametric-Refraction Tomography) Sanshiro Enomoto University of Washington CIDER Geoneutrino Working Group Meeting, UCSB, 1 July 2014

2 Everything Shown Here was Taken from: 2 and references in there

3 Atmospheric Neutrinos primary cosmic ray (proton) Super-Kamiokande in Japan (10 MeV ~ 100 GeV) 3 40 m 50 kt Ice Cube at South Pole (100 GeV ~ ) Detection by Charged-Current ν µ + N + X 1000 m Deep-Core (10 GeV ~ ) 0.02 km 3 1 km 3

4 Atmospheric Neutrinos and Neutrino Oscillation 4 Probability of detecting ν μ after distance L P ( ν µ ν µ ) ν µ 1- sin L E / km / GeV (w/o matter effects) ν e ν τ Energy (GeV) Survival Probability 10 GeV Zenith Angle Distance

5 Oscillation Tomography using Matter Effect Neutrino oscillation is affected by Electron Density 5 D. R. Grant, Neutrino 2014

6 Neutrino Oscillation though Earth P( ν µ ~ P( ν µ Normal Hierarchy IH P( ν µ ~ P( ν µ Inverted Hierarchy NH 6 Energy (GeV) Survival Probability Energy (GeV) Survival Probability 10 GeV cos(zenith angle) cos(zenith angle) Core

7 Neutrino Oscillation though Earth P( ν µ ~ P( ν µ Normal Hierarchy IH P( ν µ ~ P( ν µ Inverted Hierarchy NH 7 Energy (GeV) MSW Resonance on θ 13 (adiabatic) & Parametric Enhancement (non-adiabatic) Survival Probability Energy (GeV) Survival Probability 10 GeV cos(zenith angle) cos(zenith angle) Core

8 Neutrino Oscillation though Earth P( ν µ ~ P( ν µ Normal Hierarchy IH P( ν µ ~ P( ν µ Inverted Hierarchy NH 8 Energy (GeV) MSW Resonance on θ 13 (adiabatic) & Parametric Enhancement (non-adiabatic) Survival Probability Energy (GeV) Survival Probability 10 GeV cos(zenith angle) cos(zenith angle) Core

9 Neutrino Oscillation though Earth P( ν µ ~ P( ν µ Normal Hierarchy IH P( ν µ ~ P( ν µ Inverted Hierarchy NH 9 Energy (GeV) MSW Resonance on θ 13 (adiabatic) & Parametric Enhancement (non-adiabatic) Survival Probability Energy (GeV) Survival Probability 10 GeV cos(zenith angle) cos(zenith angle) Core

10 Sensitivity to Core Z/A If Density is known, electron density gives Z/A ratio Z/A Ratio: Hydrogen: 1 Light Elements: 0.5 Mantle (Pyrolite): % difference Iron: Iron Core (Z/A=0.4656) Normal Hierarchy Pyrolite (Z/A=0.4957)

11 Wish List Gigantic Detector (~ Mega ton) Dense Detector (~1 GeV threshold) Good Energy and Angular Sensitivity Normal Hierarchy Preferred (antineutrino cross-section is smaller) Atmospheric Neutrino Flux 11 Neutrino Charged-Current Cross-section Ice-Cube is too sparse (Deep-Core detects E >10GeV) Super-Kamiokande is too small (total 50 k-ton)

12 PINGU: Ice-Cube Upgrade for Lower Energy 12 arxiv: (9 Jan 2014) ~3 M-ton effective volume x20 photo cathode density sensitivity downto few GeV $100M, ready in ~5 years

13 Hyper-Kamiokande (Super-K successor) 13 arxiv: (15 Sep 2011) 0.99 M-ton 20% photo coverage few MeV threshold

14 PINGU: Sensitivity to Core Z/A 14 Iron Core Pyrolite Normal Hierarchy Difference in ν μ Survival Probability PINGU volume (40 string) PINGU energy resolution (ΔE/E = 0.33) PINGU angular resolution (Δθ=15 ) PINGU systematic errors Difference in Number of Events Normal Hierarchy 0.45 Inverted Hierarchy yr 1 yr

15 PINGU: Sensitivity to Core Z/A 15 PINGU 5 yr Fe: Pyrolite: (+6.5% to all-fe)

16 PINGU: Sensitivity to Core Z/A 16 PINGU 5 yr Fe: Pyrolite: (+6.5% to all-fe) Fe + H (1 wt%): (+1.0% to all-fe)

17 PINGU: Sensitivity to Core Z/A 17 Pyrolite model can be tested at 1σ after 5 years (Normal Hierarchy) Inverted Hierarchy will limit the sensitivity to ~20%, because antineutrino cross-section is half of neutrinos... Dependence on θ 13 value is small Better energy resolution will largely improve the sensitivity

18 Hyper-Kamiokande might do it better 18 Better energy and angular resolutions ν e channel usable Smaller active volume?? 50 m HK: 1 M-ton water cherenkov PINGU Hyper-Kamiokande

19 Low-energy sensitivity increases effective volume 19 Hyper-Kamiokande Letter of Intent arxiv: (15 Sep 2011) PINGU Partially-Contained Event μ ν μ

20 Neutrino Absorption Tomography Kotoyo Hoshina, AGU Fall

21 Neutrino Absorption Tomography Kotoyo Hoshina, AGU Fall

22 Neutrino Absorption Tomography Kotoyo Hoshina, AGU Fall

23 Neutrino Absorption Tomography Kotoyo Hoshina, AGU Fall

24 Appendix: Parametric Enhancement is Sensitive to CMB? 24 Energy (GeV) MSW Resonance on θ 13 (adiabatic) & Parametric Enhancement (non-adiabatic) Survival Probability 10 GeV Transition probability depends on structures of density step cos(zenith angle) Core

25 Summary 25 Neutrino Oscillation Tomography Direct measurement of core composition Uses oscillation matter effect (MSW) at 1~10 GeV PINGU will measure Z/A at ~8% accuracy (NH case), possibly better Inverted hierarchy will limit the sensitivity to ~20% Hyper-Kamiokande might be able to do it better ORCA (KM3NeT, 1.8 M-ton in sea water) can do the same? Neutrino Absorption Tomography Direct measurement of core density Uses neutrino absorption at ~10 TeV 10 yr Ice-Cube will discriminate core from mantle

26 Back Up 26

27 Photo Coverage vs Energy Threshold 27 D. R. Grant, Neutrino 2014

28 MSW Resonance 28 antineutrinos neutrinos

29 Atmospheric Neutrino Composition 29 M. Honda et al, Phys Rev D 70, (2004)