Toward Precision Neutrino Physics with Deepcore and Beyond

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Toward Precision Neutrino Physics with DeepCore and Beyond

Tyce DeYoung Department of Physics Pennsylvania State University

VLVνT ’11 Erlangen, Germany October 14, 2011 The Neutrino Detector Spectrum

Accelerator-based

Energy ↔ Volume

10 MeV 100 MeV 1 GeV 10 GeV 100 GeV 1 TeV 10 TeV 1 EeV

Atmospheric/Astrophysical The Neutrino Detector Spectrum

Accelerator-based

Energy ↔ Volume

10 MeV 100 MeV 1 GeV 10 GeV 100 GeV 1 TeV 10 TeV 1 EeV SNO, Borexino, Super-K, KamLAND, LBNE Double CHOOZ, Daya Bay, etc. Atmospheric/Astrophysical The Neutrino Detector Spectrum

NOνA OPERA Accelerator-based K2K, MINOS T2K MiniBooNE Energy ↔ Volume

10 MeV 100 MeV 1 GeV 10 GeV 100 GeV 1 TeV 10 TeV 1 EeV SNO, Borexino, Super-K, KamLAND, LBNE Double CHOOZ, Daya Bay, etc. Atmospheric/Astrophysical The Neutrino Detector Spectrum

NOνA OPERA Accelerator-based K2K, MINOS T2K MiniBooNE Energy ↔ Volume

10 MeV 100 MeV 1 GeV 10 GeV 100 GeV 1 TeV 10 TeV 1 EeV ANITA, SNO, Borexino, Super-K, AMANDA, Baikal, RICE, Auger, KamLAND, LBNE ANTARES IceCube, KM3NeT ARIANNA,... Double CHOOZ, Daya Bay, etc. Atmospheric/Astrophysical The Neutrino Detector Spectrum

NOνA OPERA Accelerator-based K2K, MINOS T2K MiniBooNE Energy ↔ Volume

10 MeV 100 MeV 1 GeV 10 GeV 100 GeV 1 TeV 10 TeV 1 EeV ANITA, SNO, Borexino, Super-K, AMANDA, Baikal, RICE, Auger, KamLAND, LBNE ANTARES IceCube, KM3NeT ARIANNA,... Double CHOOZ, Gap Daya Bay, etc. Atmospheric/Astrophysical Gamma Ray Bursts Neutrino Oscillations Soft Galactic Dark Cosmic Ray Matter Accelerators The Neutrino Detector Spectrum

NOνA OPERA Accelerator-based K2K, MINOS T2K MiniBooNE Energy ↔ Volume

10 MeV 100 MeV 1 GeV 10 GeV 100 GeV 1 TeV 10 TeV 1 EeV ANITA, SNO, Borexino, Super-K, AMANDA, Baikal, RICE, Auger, KamLAND, LBNE DeepCore ANTARES IceCube, KM3NeT ARIANNA,... Double CHOOZ, Daya Bay, etc. Atmospheric/Astrophysical Gamma Ray Bursts Neutrino Oscillations Soft Galactic Dark Cosmic Ray Matter Accelerators IceCube DeepCore

• IceCube collaboration decided to augment “low” energy response with a densely instrumented inﬁll array: DeepCore

• Signiﬁcant improvement in capabilities from ~10 GeV to ~100 GeV (νμ)

• Primary scientiﬁc rationale was the indirect search for dark matter

• Particle physics using atmospheric neutrinos • Neutrino oscillations, including tau neutrino appearance

• Neutrino sources in Southern Hemisphere? • Galactic cosmic ray accelerators, dark matter in the Galactic center

• Neutrino astronomy at low energies (e.g. GRBs)?

Tyce DeYoung VLVνT ’11, Erlangen, Germany October 14, 2011 IceCube DeepCore scattering

• Eight special strings plus 12 nearest standard IceCube strings • 72 m interstring spacing IceCube

• 7 m DOM spacing extra veto cap • High Q.E. PMTs • ~5x higher effective AMANDA photocathode density Deep • In the clearest ice, below 2100 m Core 350 m • λatten ≈ 40-45 m

• 30 MTon detector with ~10 GeV 250 m threshold, O(105) atm. ν / year

• IceCube is an active veto against cosmic ray muon background IceCube DeepCore scattering

• Eight special strings plus 12 nearest standard IceCube strings • 72 m interstring spacing IceCube

• 7 m DOM spacing extra veto cap • High Q.E. PMTs • ~5x higher effective AMANDA photocathode density Deep • In the clearest ice, below 2100 m Core 350 m • λatten ≈ 40-45 m

• 30 MTon detector with ~10 GeV 250 m threshold, O(105) atm. ν / year

• IceCube is an active veto against cosmic ray muon background DeepCore Neutrino Effective Area ) ) 2 2 IceCube Trigger w/o DeepCore IceCube Trigger w/o DeepCore 10 DeepCore+IceCube Trigger 10 DeepCore+IceCube Trigger DeepCore Online Filter DeepCore Online Filter 1 1

10-1 10-1 Effective Area (m Effective Area (m DeepCore 10-2 DeepCore 10-2

10-3 10-3

10-4 10-4 without νe without νμ 10-5 10-5 DeepCore DeepCore 10-6 10-6 1.0 1.5 2.0 2.5 3.0 3.5 4.0 1.0 1.5 2.0 2.5 3.0 3.5 4.0 Log (ν Energy - GeV) Log (ν Energy - GeV) 10 e 10 µ

• DeepCore dominates total response for Eν below ~100 GeV • Improved trigger efficiency overcomes much smaller volume • Linear growth at high energy reflects neutrino cross section, not detector efficiency • Analysis efficiencies not included! First analyses accepted low (<10%) efficiency, expected to improve considerably in the future Neutrino Astronomy with DeepCore

• Atmospheric neutrino veto? • May enhance observability of Galactic sources in the ~10 TeV band (Schönert et al. 2009) • Still difﬁcult at these energies due to loss of muon range factor, rising neutrino cross section

• Sensitivity to low energy neutrinos from transients? • E.g. choked or atm. ν magnetically dominated GRBs possible source with veto (e.g., Ando & Beacom 2005; spectrum Razzaque, Meszaros & Waxman 2005; Meszaros & Rees 2011)

Tyce DeYoung VLVνT ’11, Erlangen, Germany October 14, 2011 Search for Solar Dark Matter Analysis Results from the Sun • Solar WIMP dark matter searches probe spin-dependent scattering cross section details on SUSY-WIMP limits: details on LKP limits: Abbasi et al., PRL. 102, 201302 (2009) (IC22 result) Abbasi et al., PRD 81 (2010) 057101. (IC22 result) ICRC 2011 (IC40+AMANDA result) ICRC 2011 (IC40+AMANDA result) • SI cross section constrainedICRC 2011 (IC86 well sensitivity) by direct search experiments

• DeepCore is limits & sensitivity: essential to low Only data, when Sun is mass WIMPs below the horizon

(below about main syst. uncertainty: 100 GeV) Photon propagation in the ice & absolute • For non-SUSY DOM efficiency (~20%) DM, even lower energies are of relate muon flux and WIMP - nucleon cross≠ interest section:

07/09/11 Matthias Danninger TAUP 2011 9 Mena, Mocioiu & Razzaque, Phys. Rev. D78, 093003 (2008) Neutrino Oscillations

ντ appearance

• Atmospheric neutrinos from Northern Hemisphere oscillating νμ disappearance over one earth diameter have νμ oscillation minimum at ~25 GeV L = D • Higher energy region than accelerator-based experiments

1400 Preliminary • Plot of νμ disappearance shows Unoscillated 1200 Oscillated only simulated signal (no BG), No Reconstruction 1000 θ = π/2 simple energy estimator 23 2 -3 Δm23 = 2.4 × 10 eV 800 ~15σ

Events/NChannel/Year Cos(zenith) < -0.6 • Analysis efﬁciencies not per bin included yet – work ongoing 600 400 • Magnitude of the signal may help overcome poorer 200 0 control of systematics 0 10 20 30 40 50 60 70 80 90 100 NChannels [Hit DOMs] Observation of Atmospheric Cascades Preliminary

• Disappearing νμ should appear in IceCube as ντ cascades • Effectively identical to neutral current or νe CC events

• Could observe ντ appearance as a distortion of the energy spectrum, if cascades can be separated from muon background

• We believe we see neutrino cascade events for the ﬁrst time • The dominant background now Candidate cascade event is CC νμ events with short tracks Run 116020, Event 20788565, 2010/06/06

Tyce DeYoung VLVνT ’11, Erlangen, Germany October 14, 2011 Observation of Atmospheric Cascades C. Ha, TAUP 2011

• Substantial sample of cascades, ﬁnal data set ~60% cascades • Mean energy ~180 GeV, not sensitive to oscillations (with these cuts)

• Atmospheric muon background being assessed, but νμ CC dominant

• Represents about 5x enrichment of cascades over νμ CC, but better neutrino particle ID clearly desirable • Potential to discriminate between Bartol, Honda atmospheric neutrino models – measuring air shower physics!

! Cascades CC νμ Total cascades

Bartol 650 454 1104 observed CC

Honda 551 415 966 μ ν preliminary Data 1029 Bartol Honda Data Beyond DeepCore

NOνA OPERA Accelerator-based K2K, MINOS T2K MiniBooNE Energy ↔ Volume

10 MeV 100 MeV 1 GeV 10 GeV 100 GeV 1 TeV 10 TeV 1 EeV ANITA, SNO, Borexino, Super-K, AMANDA, Baikal, RICE, Auger, KamLAND, LBNE DeepCore ANTARES IceCube, KM3NeT ARIANNA,... Double CHOOZ, PINGU & Beyond? Daya Bay, etc. Atmospheric/Astrophysical Gamma Ray Bursts Neutrino Oscillations Soft Galactic Dark Cosmic Ray Matter Accelerators Toward Precision Particle Physics in Ice

• First stage (“PINGU”) • Add ~20 further inﬁll strings to DeepCore, extend energy reach to ~1 GeV • Improved sensitivity to DeepCore physics, and test bed for next stage • Use mostly standard IceCube technology, include some R&D toward new types of photodetectors • Include additional calibration devices with an eye toward few-% systematics

• Ideas beyond PINGU • Using new photon detection technology, can we build a detector that can reconstruct Cherenkov rings for events well below 1 GeV? • PINGU topics, plus proton decay, supernova neutrinos • At least comparable in scope to IceCube, but in a much smaller volume

Tyce DeYoung VLVνT ’11, Erlangen, Germany October 14, 2011 Beyond DeepCore: PINGU

• Now developing a proposal to one possible geometry further increase density of New PINGU instrumentation in DC volume Strings • An additional 18-20 strings, 1000-1200 DOMs • Make use of well-established IceCube drilling technology • Might get to a Existing standard threshold of ~1 GeV Existing IceCube DeepCore in a ~10 MTon volume strings Strings • Also an R&D platform for future detectors on a ~decade timeline

• Price tag expected to be around $25M – $30M

Tyce DeYoung VLVνT ’11, Erlangen, Germany October 14, 2011 PINGU Effective Volumes Preliminary

100 100 Megaton Megaton 10 10

1 1

0.1 IC2011 DC Contained 0.1 IC2011 DC Contained

PINGU Contained PINGU Contained

0.01 0.01 0.0 0.5 1.0 1.5 2.0 2.5 0.0 0.5 1.0 1.5 2.0 2.5 νe Energy (Log GeV) ν Energy (Log GeV) 10 µ 10

• Increased effective volume for energies below ~15 GeV • Nearly an order of magnitude increase at 1 GeV (100’s of kton) • Does not include analysis efﬁciencies, reconstruction precision • Absolute scale lower, but improvement over DeepCore likely >10x PINGU Neutrino Physics 5 Mena, Mocioiu, Razzaque, arXiv:0803.3044 0.5 • Sensitivity to 2nd oscillation 1 2 2 sin 2 θ = 0.1 (ΝΗ) sin 2 θ = 0.1 (ΝΗ) peak/trough, and lower?13 13 2 2 sin 2 sin 2 0.4 θ13 = 0.1 (ΙΗ) 0.8 θ13 = 0.1 (ΙΗ) 2 2 sin 2 sin 2 θ13 = 0.06 (ΝΗ) θ13 = 0.06 (ΝΗ) • Measuring full minimum2 2 sin 2θ = 0.06 (ΙΗ) sin 2θ = 0.06 (ΙΗ) nd 13 13 0.3 and 2 peak would improve 0.6 ) ) µ µ ν ν

2 − −

extraction of Δm23 and e µ ν ν P(

2 P( 0.2 sin (2θ23) in a very large 0.4 data set 0.1 • Limited by systematic 0.2 uncertainties, not statistics 0 0 5 10 15 20 25 5 10 15 20 25 E [GeV] E [GeV] ν ν • Plan for a robust calibration program to reﬁne

FIG. 2:understanding left (right panel): Oscillation of systematics probabilities for νe → νµ, νµ → νµ transitions for cν = −1.

channel and thereforeTyce DeYoung is in many ways complementaryVLVνT ’11, Erlangen,falling Germany spectrum, so one would expectOctober this 14, 2011 tau-induced to the appearance experiments. While the matter effects muon background not to be very large. It is however sig- are a small correction in the νµ survival probability, they nificant ( 10%) due to the fact that, as seen in Figure 3, ∼ are sufficient to provide a difference between the differ- the first maximum in the νµ ντ oscillation probability → ent mass orderings because of the very large number of (minimum in the νµ νµ survival probability) falls ex- events. actly in the energy range→ of interest and for a large range Note that in Fig. 1 the difference between event rates the ντ flux can be significantly larger than the νµ flux. for the two hierarchies increases (although the overall These events significantly change the energy spectrum of rates decreases) for cν bins ( 0.9, 0.8) and ( 0.8, 0.7) the measured muon-like events and contain information − − − − compared to the ( 1, 0.9) bin. This is because the res- about the main oscillation parameters, ∆31 and θ23. onant matter density− − for neutrino energies in the first 3 1 energy bin =15GeVis 5g/cm which is lower ∼ ν − ν than the densities that the neutrino crosses if cν is in µ µ ν − ν the ( 1, 0.9) region, but gets closer to the ones in the µ τ − − 0.8 shallower cν region.

0.6 IV. BACKGROUNDS AND SYSTEMATIC

UNCERTAINTIES 0.4 Oscillation probabilities The main backgrounds to the signal we are exploiting 0.2 in the current study are atmospheric downward going muons from the interactions of cosmic rays in the atmo- sphere and tau (anti)neutrinos from νµ,e(¯νµ,e) ντ (¯ντ ) 0 5 10 15 20 25 30 35 40 45 50 → E [GeV] transitions. The cosmic muon background can be elimi- ν nated by angular cuts and in the Ice Cube deep core is significantly reduced compared to the IceCube detector. FIG. 3: νµ survival probability and νµ → ντ oscillation prob- − 2 The tau neutrino background can be included in the ability for cν = 1, sin 2θ13 =0.1 analysis as an additional source of µ-like events. Tau (anti)neutrinos resulting from atmospheric neutrino fla- The uncertainties in the atmospheric neutrino flux vor transitions will produce a τ lepton by CC interac- have been discussed in the previous section and they af- tions in the detector effective volume. The tau leptons fect the analysis. It is however possible to use the data produced have an 18% probability of decaying through itself to improve some of the errors introduced by these ∼ the τ − µ−ν¯µντ channel. effects, by considering energy and angular bins where os- → The secondary muons can mimic muons from νµ CC cillation effects are not important as a reference and thus interactions and must be included in the oscillated signal. canceling out some of these uncertainties in the analysis The energy of a ντ needs to be about 2.5 times higher (see also [26]). than a νµ to produce, via tau decay, a muon of the same The uncertainties in other oscillation parameters also energy. But the atmospheric neutrino flux has a steeply affect the possibility of determining the neutrino mass hi- Neutrino mass hierarchy - PINGU

We investigate the possibility of this measurement with a 20 string infill. 2 Probing the Neutrino sin (2θ13) = 0.1 Why? Mass Hierarchy? At 10 GeV the neutrino/anti- • Possible sensitivity to neutrino neutrino massprobabilities hierarchy via are matter flipped in their hierarchieseffects if θ 13and is large add = reduces the• Exploit effective asymmetries size ofin measured CCν / ν̄ crossevents section, kinematics • Effect is largest at energies below 5 GeV (for Earth At 5 GeV therediameter is abaseline) clear flip and shift in the• Controlprobabilities of systematics which crucial we may be able to exploit... • Recent results suggest that nature may have been kind to us by giving us a large θ13

September, 2011 IceCube Collaboration Meeting - Uppsala Sweden Darren R. Grant - University of Alberta PINGU HierarchyNeutrino Measurement? mass hierarchy - PINGU

• Simulations of 18-string PINGU for 5 years with 2 sin (2θ13) = 0.1 Very Preliminary !!!Normal!hierarchy! • Assumes perfect Inverted!hierarchy! background rejection, select events within 25º of vertical • 5 GeV muon energy bins – ~25 m length resolution

• Up to 20% (=10σ) effectsFresh in fromseveral the farm energy/angle - GENIE PINGU bins numu and numubar (thanks Jason!) processed. Events are SMT3 trigger level 20 string PINGU • Signal is potentially there,inﬁll. if systematics can be controlled September, 2011 IceCube Collaboration Meeting - Uppsala Sweden Darren R. Grant - University of Alberta

Tyce DeYoung VLVνT ’11, Erlangen, Germany October 14, 2011 Beyond PINGU: A Megaton Ice Cherenkov Array

• Underground detectors such as Super-K have made tremendous contributions to particle physics, but are approaching the limits of feasible detector size • Physics reach determined by photocathode coverage, radiopurity, optical quality of the medium • Costs driven primarily by photocathode coverage, puriﬁcation, and civil engineering – and the latter is coming to dominate

• Ice offers one great advantage: the medium is the support structure • Installation costs low (on the scale of a next-generation detector) • Deep ice has reasonably good optical quality, very high radiopurity • But the maximum density of instrumentation is determined by installation procedure, and the optical properties must be assessed in situ

Tyce DeYoung VLVνT ’11, Erlangen, Germany October 14, 2011 Megaton Ice Cherenkov Array

• Few hundred strings of “linear” detectors to be deployed within DeepCore • String spacings ~5 m, sensors spaced by ~1 m on a string

• Goals: ~5 MTon ﬁducial volume • O(10 MeV) threshold for bursts • O(100 MeV) for single events

• Physics extraction from Cherenkov ring imaging in the ice • IceCube and DeepCore provide active veto

• No excavation is necessary, drilling/deployment has been reﬁned to an industrial process – deployment costs would be well below 10% of total

Tyce DeYoung VLVνT ’11, Erlangen, Germany October 14, 2011 R&D: Multi-PMT Digital Optical Module

P. Kooijman & • Based on a KM3NeT design E. de Wolf

• Glass cylinder containing 64 3” PMTs and associated electronics

• Several times the photocathode area of a Possible standard IceCube 10” PMT design for future • Module diameter similar to array: IceCube DOM, single connector 64 x 3” PMTs • Might enable Cherenkov ring imaging in the ice • Feasible to build a multi-MTon detector in ice with an energy threshold of 10’s of MeV?

• R&D beginning (U. Katz/P. Kooijman) Possible design for future array: 64 x 3” PMTs Physics Goals

• Proton decay • Studying sensitivity to p → π0 + e+ channel • Requires energy threshold of ~100’s of MeV • Background limited – depends on energy resolution, particle (ring) ID

• Supernova neutrinos • Need to reach well beyond our galaxy to get statistical sample of SN neutrinos – requires multi-MTon effective volume • Background levels may be too high for a ~10 MeV threshold for individual events, but still allow observations of a burst of neutrinos

• Plus improvements for dark matter, neutrino physics compared to PINGU and DeepCore

Tyce DeYoung VLVνT ’11, Erlangen, Germany October 14, 2011 Proton Decay

• Studying use of ring imaging algorithms from underground detectors (e.g. Super-K) in a volume-instrumented detector • Need to understand energy resolution, e/μ ring identiﬁcation, required photocathode coverage • Photocathode density equivalent to ~10-15% coverage is technically feasible based on deployment technology (but would be expensive) • What information do we gain from always having segmented photodetectors near the event vertex? How can we incorporate it?

• Proton lifetimes of 1036 years are theoretically interesting, current limits (mostly Super-K) are around several times 1034 years • Need to assess detector performance before we understand our sensitivity

Tyce DeYoung VLVνT ’11, Erlangen, Germany October 14, 2011 Supernovae

• Work in progress to assess the ability to detect SN neutrinos

• Background constraints more difﬁcult but threshold may be lowered for bursts of events

M. Kowalski Figure: Lukas Schulte/Mainz

Geant4: γ’s from SN ν’s Timeline

• Detailed Monte Carlo simulations underway • Low energy reconstruction will follow work on DeepCore now underway • Cherenkov ring reconstruction can modify existing algorithms from experiments like SuperK

• We aim for a PINGU proposal soon, deploy within next few years

Winter Winter Winter 2012 2011 2014/15 2015/16 Establish R&D plans as 1st DC papers Begin Finish deploying part of PINGU deploying PINGU including PINGU PINGU white paper Submit PINGU Proposal PINGU R&D strings

March 2011 2021 R&D Submit Start First PINGU Feasibility proposals to proposals to deployment workshop - NIKHEF studies Agencies Agencies phase B SuperPINGU Summer 2012 Fall 2012 2016 Winter 2018/19