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

1

Everything Shown Here was Taken from: 2

and references in there

Atmospheric Neutrinos 3

Ice Cube at South Pole

Super-Kamiokande in Japan

40 m

1000 m 0.02 km3

1 km3

50 kt

primary cosmic ray (proton) (10 MeV ~ 100 GeV)

(100 GeV ~ )

XN +→+ −µν µ

Detection by Charged-Current

Deep-Core (10 GeV ~ )

Atmospheric Neutrinos and Neutrino Oscillation 4

Surv

ival P

robability

Zenith Angle ⇒ Distance

Energ

y (G

eV

) 10 GeV

⋅×≈→ −

GeV/km/103sin - 1)( 32

ELP µµ νν

Probability of detecting νμ after distance L

µν

τνeν

(w/o matter effects)

Oscillation Tomography using Matter Effect 5

D. R. Grant, Neutrino 2014

Neutrino oscillation is affected by Electron Density

Neutrino Oscillation though Earth 6

Hierarchy Normal)( −→ µµ ννPIH)(~ −→ µµ ννP

Hierarchy Inverted)( −→ µµ ννPNH)(~ −→ µµ ννP

10 GeV

cos(zenith angle) cos(zenith angle)

Surv

ival P

robability

Energ

y (G

eV

)

Energ

y (G

eV

) Surv

ival P

robability

Core

Neutrino Oscillation though Earth 7

Hierarchy Normal)( −→ µµ ννPIH)(~ −→ µµ ννP

Hierarchy Inverted)( −→ µµ ννPNH)(~ −→ µµ ννP

10 GeV

Core

MSW Resonance on θ13

(adiabatic)

cos(zenith angle) cos(zenith angle)

Energ

y (G

eV

)

Energ

y (G

eV

) Surv

ival P

robability

Surv

ival P

robability

Parametric Enhancement (non-adiabatic)

&

Neutrino Oscillation though Earth 8

Hierarchy Normal)( −→ µµ ννPIH)(~ −→ µµ ννP

Hierarchy Inverted)( −→ µµ ννPNH)(~ −→ µµ ννP

10 GeV

Core

cos(zenith angle) cos(zenith angle)

Energ

y (G

eV

)

Energ

y (G

eV

) Surv

ival P

robability

Surv

ival P

robability

MSW Resonance on θ13

(adiabatic)

Parametric Enhancement (non-adiabatic)

&

Neutrino Oscillation though Earth 9

Hierarchy Normal)( −→ µµ ννPIH)(~ −→ µµ ννP

Hierarchy Inverted)( −→ µµ ννPNH)(~ −→ µµ ννP

10 GeV

Core

cos(zenith angle) cos(zenith angle)

Energ

y (G

eV

)

Energ

y (G

eV

) Surv

ival P

robability

Surv

ival P

robability

MSW Resonance on θ13

(adiabatic)

Parametric Enhancement (non-adiabatic)

&

Sensitivity to Core Z/A 10

Iron Core (Z/A=0.4656) Pyrolite (Z/A=0.4957)

Normal Hierarchy

Z/A Ratio: Hydrogen: 1 Light Elements: 0.5 Mantle (Pyrolite): 0.4957 Iron: 0.4656

6.5% difference

If Density is known, electron density gives Z/A ratio

Wish List 11

Gigantic Detector (~ Mega ton) Dense Detector (~1 GeV threshold) Good Energy and Angular Sensitivity Normal Hierarchy Preferred (antineutrino cross-section is smaller)

• Ice-Cube is too sparse (Deep-Core detects E >10GeV)

• Super-Kamiokande is too small (total 50 k-ton)

Neutrino Charged-Current Cross-section

Atmospheric Neutrino Flux

PINGU: Ice-Cube Upgrade for Lower Energy 12

arXiv:1401.2046 (9 Jan 2014)

~3 M-ton effective volume x20 photo cathode density sensitivity downto few GeV $100M, ready in ~5 years

Hyper-Kamiokande (Super-K successor) 13

arXiv:1109.3262 (15 Sep 2011)

0.99 M-ton 20% photo coverage few MeV threshold

PINGU: Sensitivity to Core Z/A 14

Iron Core Pyrolite

Normal Hierarchy Difference in νμ 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 Inverted Hierarchy 0.45

-0.45

0

0.20

-0.20

0

1 yr 1 yr

PINGU: Sensitivity to Core Z/A 15

Fe: 0.4656 Pyrolite: 0.4957 (+6.5% to all-Fe)

PINGU 5 yr

PINGU: Sensitivity to Core Z/A 16

Fe: 0.4656 Pyrolite: 0.4957 (+6.5% to all-Fe)

PINGU 5 yr

Fe + H (1 wt%): 0.4709 (+1.0% to all-Fe)

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 θ13 value is small Better energy resolution will largely improve the sensitivity

Hyper-Kamiokande might do it better 18

Hyper-Kamiokande

Better energy and angular resolutions νe channel usable

• Smaller active volume??

PINGU

HK: 1 M-ton water cherenkov

50 m

Low-energy sensitivity increases effective volume 19

Hyper-Kamiokande Letter of Intent arXiv:1109.3262 (15 Sep 2011)

PINGU

Partially-Contained Event

μ

νμ

Neutrino Absorption Tomography 20

Kotoyo Hoshina, AGU Fall 2012

Neutrino Absorption Tomography 21

Kotoyo Hoshina, AGU Fall 2012

Neutrino Absorption Tomography 22

Kotoyo Hoshina, AGU Fall 2012

Neutrino Absorption Tomography 23

Kotoyo Hoshina, AGU Fall 2012

Appendix: Parametric Enhancement is Sensitive to CMB?

24

10 GeV

Core

cos(zenith angle)

Energ

y (G

eV

) Surv

ival P

robability

MSW Resonance on θ13

(adiabatic)

Parametric Enhancement (non-adiabatic)

&

Transition probability depends on structures of density step

Summary

• 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

25

26

Back Up

Photo Coverage vs Energy Threshold 27

D. R. Grant, Neutrino 2014

MSW Resonance 28

antineutrinos neutrinos

Atmospheric Neutrino Composition 29

M. Honda et al, Phys Rev D 70, 043008 (2004)