Particle Physics in Ice with Icecube Deepcore

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Particle Physics in Ice with IceCube DeepCore

Tyce DeYoung Department of Physics Pennsylvania State University for the IceCube Collaboration

RICAP ’11 Rome, Italy May 25, 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, KamLAND, Super-K 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, KamLAND, Super-K 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, AMANDA, Baikal, RICE, Auger, Super-K KamLAND, 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, AMANDA, Baikal, RICE, Auger, Super-K KamLAND, ANTARES IceCube, KM3NeT ARIANNA,... Double CHOOZ, Gap 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, AMANDA, Baikal, RICE, Auger, Super-K KamLAND, 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 is 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 RICAP ’11 May 25, 2011 Overhead View 2010 conﬁguration

IceCube DeepCore

DeepCore • DeepCore extends the reach of IceCube to lower energies • Denser module spacing scattering • Hamamatsu super-bialkali PMTs IceCube Strings HQE DeepCore Strings DeepCore Infill Strings (Mix of HQE and • Deployed in the clearest ice normal DOMs)

DeepCore strings have Side View 10 DOMs with a DOM-to-DOM spacing of 10 meters

Dust Layer

50 HQE DOMs with an DOM-to-DOM spacing of 7 meters

21 Normal DOMs with a DOM-to-DOM spacing of 17 meters Overhead View 2010final configurationconfiguration

IceCube DeepCore

DeepCore strings have Side View 10 DOMs with a DOM-to-DOM spacing of 10 meters

Dust Layer

50 HQE DOMs with an DOM-to-DOM spacing of 7 meters

21 Normal DOMs with a DOM-to-DOM spacing of 17 meters Online Atmospheric Muon Veto

• Look for hits in veto region consistent with speed-of-light travel time to hits in DeepCore • Achieves 7 x 10-3 rejection of cosmic ray muon background • Loss of <2% of ﬁducial neutrinos

Preliminary (Monte Carlo) speed of light (inward)

speed of light (outward) cosmic ray muons neutrinos DeepCore Lepton Effective Volume

200 200 DeepCore Trigger DeepCore Trigger DeepCore Online Filter DeepCore Online Filter IceCube Trigger w/o DC IceCube Trigger w/o DC Megaton Megaton 150 150 300 m

100 Physical 100 Deep Core Volume 400 m ~28 MT 50 50 νe νμ 0 0 1.0 1.5 2.0 2.5 3.0 1.0 1.5 2.0 2.5 3.0 !e Energy (Log10 GeV) !µ Energy (Log10 GeV)

• Many DeepCore triggers are events occurring in the rest of IceCube • These events are rejected by the online veto algorithm • Online efficiency for neutrinos interacting in the DeepCore volume is >98% • Efficiency in final analysis will be significantly lower; losses to reconstruction efficiency, background rejection 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 10-2 10-2

10-3 10-3

10-4 10-4 νe νμ 10-5 10-5

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 (! Energy - GeV) Log (! Energy - GeV) 10 e 10 µ

• DeepCore dominates total response for Eν below ~100 GeV, depending on flavor • Improved trigger efficiency overcomes much smaller volume • Linear growth at high energies reflects neutrino interaction cross section, not detector efficiency Neutrino Astronomy with DeepCore

• Atmospheric neutrino veto • May allow observation of sources in the Southern hemisphere with ﬂuxes too low to be seen above atmospheric background (Schönert et al. 2009)

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

Tyce DeYoung RICAP ’11 May 25, 2011 Sensitivity to MSSM WIMPs

0.05 < 1 h2 < 0.20 MSSM model scan -31 r )

2 10 m < mlim CDMS(2010)+XENON100(2010) CDMS (2010) • Solar WIMP SI SI COUPP (2008) -32 m < 0.001xmlim CDMS(2010)+XENON100(2010) 10 SI SI KIMS (2007) dark matter IceCube (bb) Picasso (2009) + - + - SUPER-K 1996-2001 -33 IceCube (W W , o o for m] < mW = 80.4GeV) 10 + - + - searches probe IC80+DC6 sens.(180d) (W W , o o for m] < mW = 80.4GeV) *IceCube PRELIMINARY* SD scattering 10-34 cross section 10-35

-36 • SI cross section 10 Direct Detection Experiments 10-37 constrained well Super-K IceCube soft spectrum by direct search 10-38

experiments 10-39 IceCube hard spectrum Neutralino-proton SD cross-section (cm

-40 10 IceCube+DeepCore hard spectrum(prelim.) sensitivity • DeepCore will -41 10 ( Lines are to Allowed probe large guide the eye ) MSSM models 10-42 10 102 103 104 region of Neutralino mass (GeV) allowed phase space Corresponding σSI more than factor Corresponding σSI within factor 103 beyond current direct limits 103 of current direct limits 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

Unoscillated 1200 Oscillated • Plot of νμ disappearance shows No Reconstruction 1000 "23 = !/2 only simulated signal 2 -3 $m23 = 2.4 # 10 eV 800

Events/NChannel/Year Cos(zenith) < -0.6

• Analysis efﬁciencies not 600 included yet – work ongoing 400

• Uses number of hit DOMs as 200

a simple energy estimator 0 0 10 20 30 40 50 60 70 80 90 100 NChannels [Hit DOMs]

Tyce DeYoung RICAP ’11 May 25, 2011 Observation of Neutrino 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 RICAP ’11 May 25, 2011 Observation of Neutrino Cascades (Preliminary)

• With harsh cuts to eliminate the νμ Data from 10% Preliminary background we “open” sample

expect to obtain a Rate (mHz)

sample of ~800 Rate (per year) neutrino cascades Sum of all MCs per year

• Approximately 500 νe + νμ NC (~800 / year) background νμ CC νμ CC events expected Corsika (no events in current sample) • Contamination from Jun. 2010 Aug. 2010 Oct. 2010 Dec. 2010 Feb. 2011 atmospheric muons Month still being evaluated

• Efforts to increase νe yield and reduce νμ CC background ongoing

Tyce DeYoung RICAP ’11 May 25, 2011 Observation of Neutrino Cascades (Preliminary)

• With harsh cuts to eliminate the νμ Data from 10% Preliminary background we “open” sample

expect to obtain a Rate (mHz)

sample of ~800 Rate (per year) neutrino cascades Sum of all MCs per year “Anything worth doing” • Approximately 500 νe + νμ NC (~800 / year) background νμ CC is worthνμ CCoverdoing events expected Corsika (no events in current sample) • Contamination from Jun. 2010 Aug. 2010 Oct. 2010 Dec. 2010 Feb. 2011 atmospheric muons Month still being evaluated

• Efforts to increase νe yield and reduce νμ CC background ongoing

Tyce DeYoung RICAP ’11 May 25, 2011 Beyond DeepCore: PINGU

• Now developing a proposal one possible geometry to continue to instrument the New PINGU DeepCore volume Strings • An additional 18-20 strings, 1000-1200 DOMs • Make use of well-established IceCube drilling technology • Might get to a threshold Existing standard of ~1 GeV in a ~10 MTon Existing IceCube DeepCore 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 RICAP ’11 May 25, 2011 R&D: Multi-PMT Digital Optical Module

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

• Glass cylinder containing 64 Possible 3” PMTs and associated electronics design for future • Effective photocathode area >6x that of a array: standard IceCube 10” PMT 64 x 3” PMTs • Diameter similar to IceCube DOM, single connector

• 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? Courtesy E. de Wolf & P. Kooijman

Possible design for future array: 64 x 3” PMTs Conclusions

• DeepCore has been running for 1 year, just commenced taking data in ﬁnal conﬁguration • Additional 8 strings, densely instrumenting the inner 30 MTon of IceCube • Reduce energy threshold to ~10 GeV

• Signiﬁcant improvement in sensitivity to dark matter, potential for measurements of neutrino oscillations, low energy astrophysical neutrinos • Preliminary analysis suggests we may have detected atmospheric electron neutrinos for the ﬁrst time in a high energy neutrino telescope

• Thinking about a future upgrade of IceCube to further extend its particle physics capabilities – PINGU • In the more distant future, could we build a Cherenkov ring imager in ice?