PINGU and the Neutrino Mass Hierarchy · 2014-07-04 · PINGU DeepCore IceCube. K. Clark - ICHEP...

PINGU and the Neutrino Mass Hierarchy

Ken Clark (for the IceCube-PINGU collaboration)University of Toronto

K. Clark - ICHEP 2014

The IceCube Neutrino Telescope

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IceCube

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PINGU Geometry - 26m String Spacing

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IceCube

See “Astrophysical Neutrinos with the IceCube Detector” Saturday at 11:30


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PINGU Geometry - 26m String Spacing

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DeepCore IceCube

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PINGU Geometry V15 (Ellett)

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• 78 Strings


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IceCube + DeepCore + PINGU

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DeepCorePINGU IceCube


Mass Hierarchy Determination• Lower energy atmospheric neutrinos

provide the required large flux of neutrino events

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Trigger Level

(per year)

Analysis Level

(per year)

νμ CC 86k 35k

νe CC 52k 26k

ν𝜏 CC 6.4k 2.7k

νX NC 17k 7.9k

“Tracks”

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Mass Hierarchy Determination• Experiments use the difference in MSW effect for ν and anti-ν• Combine with difference in ν and anti-ν cross-section• Variation in probability up to 20%

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Neutrino Oscillograms• The cross-

section and flux are different for νμ and νμ

• Counts will be derived from the essentially the addition of both graphs

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Mass Hierarchy Determination

• Difference in counts between hierarchies illustrates distinguishability

• Red areas indicate a surplus in IH, blue in NH

• Event selection, reconstruction not included here

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Cascade-Like Events Track-Like Events


Distinguishability

• Includes proper reconstruction of the events

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The Bottom Line

• Critically important question is how long does it take to make a measurement?

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For more details see the PINGU LoI, arXiv:1401.2046

IH True


Systematics• Impact on the final significance of several of the most

important shown here (study performed with each systematic turned off to determine the magnitude of the effect)

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World Average +/- 1σ



+/-15%

+/-15%

+/-5%

Factor of E, σ(ν), σ(ν)

K. Clark - ICHEP 2014 13

Future of the NMH Measurement• several caveats

• median statistical outcome shown

• width indicates effect of main uncertainty (δCP, θ23)

• dates are current as of the manufacture of the plot


Other Physics

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• The lowered energy threshold also facilitates several other fields of study

• muon neutrino disappearance

• maximal θ23 measurement

• neutrino tomography

• lower energy dark matter

• neutrino mass hierarchyFor more details see the PINGU LoI, arXiv:1401.2046


PINGU Advantages• Use of IceCube deployment techniques

and similar hardware reduces risk• Could be quick (2 years of acquisition/

fabrication, 2-3 years for deployment)• Relatively inexpensive• Fits well into the next phases of IceCube

extensions

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Conclusion• IceCube and DeepCore have been

very successful and have shown that particle physics is possible in ice

• PINGU will provide insight into the nature of the NMH for a very inexpensive total cost

• Many other physics topics addressed by the IceCube extensions

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K. Clark - ICHEP 2014 17


Backup

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Indirect Dark Matter Detection

• Possible to reach masses down to ~5GeV• Width indicates a variation of the detector

efficiency

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PINGU and the Neutrino Mass Hierarchy · 2014-07-04 · PINGU DeepCore IceCube. K. Clark - ICHEP...

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Transcript of PINGU and the Neutrino Mass Hierarchy · 2014-07-04 · PINGU DeepCore IceCube. K. Clark - ICHEP...