Cosmic Rays in IceCube Patrick Berghaus University of Delaware - PowerPoint PPT Presentation

Cosmic Rays in IceCube Patrick Berghaus University of Delaware

IceCube Components IceTop Surface Array: Surface: 1km 2 area 2835 m a.s.l LE electromagnetic -1450 m InIce Volume Detector: 1km 3 volume -2450 m HE muons -2620 m Patrick Berghaus Cosmic Rays in IceCube

Electromagnetic Particles (10s-100s of MeV) IceTop LE Muons Surface Array (1-10 GeV) HE Muons Primary Energy: (TeV) 1-100s PeV InIce InIce Muon Multiplicity: 10s-1000s Shower Axis Patrick Berghaus 3 Cosmic Rays in IceCube

CR Energy range of IceCube/IceTop Knee Main Science Goals: IceCube CR events Second Knee? Primary composition change around Knee Ankle Transition to IceTop Extragalactic CR Coincident at “Second Knee”? Patrick Berghaus 4 Cosmic Rays in IceCube

Temporary Cover 2 Tanks per Station Freezing Unit IceTop Deployment Patrick Berghaus 5 Cosmic Rays in IceCube

IceTop Station Patrick Berghaus 6 Cosmic Rays in IceCube

IceTop Tank Snow Height snow perlite view from above, unfrozen 65cm DOM DOM x2 x78 130cm water 93cm Patrick Berghaus 7 Cosmic Rays in IceCube

Effect of Snow Coverage (Reconstructed Shower Core Position) a.u. Oldest (2005/06) Newest (2009/10) Patrick Berghaus 8 Cosmic Rays in IceCube

IceTop Calibration Procedure Patrick Berghaus 9 Cosmic Rays in IceCube

Tank Calibration Snow reduces EM signal, muons unaffected Muon Peak /EM Bkg Snow Height Source: T. Waldenmaier, DESY-Zeuthen Patrick Berghaus 10 Cosmic Rays in IceCube

Snow Effects in Detector Simulation Here: Parametrization of detector response in dependence of particle type and snow height Soon: Full GEANT-4 simulation Red: Default Response Parametrization Blue: Zenith Angle Shower Core Position Snow Attenuation and individual Snow Height for each tank Patrick Berghaus 11 Cosmic Rays in IceCube

IceTop Shower Reconstruction (slope) (amplitude) arXiv: 0711.0353 “Double-Logarithmic Parabola”: E prim = f(S 125 , θ zen ) MC-derived empirical description Patrick Berghaus 12 Cosmic Rays in IceCube

IceTop Event Reconstruction All IceTop Waveforms color: time size: signal Estimated Energy: 183 PeV Zenith Angle: 50° Patrick Berghaus 13 Cosmic Rays in IceCube

Raw IceTop-only CR Spectrum Below Knee (E -2.7 ) Above Knee (E -3 ) Patrick Berghaus 14 Cosmic Rays in IceCube

InIce Muon Flux (IC22, 2008) Muons 99.999% of events (directly) from CR Neutrinos arXiv:0902.0021 Patrick Berghaus 15 Cosmic Rays in IceCube

Muon Spectrum Derived from IC22 (1month), PRELIMINARY! muon tracks near the horizon Higher angles: High-multiplicity muon bundles dominate over single HE muons astro-ph:0803.2943 Patrick Berghaus 16 Cosmic Rays in IceCube

Muon Energy Losses in Matter (Ice) few TeV proportional losses (high-E muons) minimum ionizing (muons in large air showers) hep-ph/0407075 continuous stochastic Patrick Berghaus 17 Cosmic Rays in IceCube

High-Energy Muon Identify stochastic losses to distinguish HE muons from high-multiplicity muon bundles Small signal from continuous E-losses Size: PMT Signal Catastrophic E-loss (Bremsstrahlung) >50 TeV Color: Time Patrick Berghaus 18 Cosmic Rays in IceCube

Prompt Leptons from Charm Decay For vertical muons, prompt Light mesons: Flux α 1/cos θ zen component becomes dominant Prompt: constant angular Flux at ≈ 200 TeV µ ν Source: T. Gaisser At 60 ° , light meson decay Charm represents major dominates systematic uncertainty for up to ≈ 500TeV neutrinos above 100 TeV Patrick Berghaus 19 Cosmic Rays in IceCube

IceTop Reco: ∆ log 10 E ≃ 0.1 (prim) ∆θ ≃ 1 ◦ ∆ r ≃ 20 m Reconstructions are completely Independent InIce Reco: Relation between ∆ log 10 E ≃ 0.3 ( µ ) energies depends ∆θ ≃ 0.7 ◦ On CR primary type ∆ r ≃ 30 m Shower Axis Patrick Berghaus 20 Cosmic Rays in IceCube

IceTop/InIce Coincident Event Shower core fully contained in IceTop array Size: PMT Signal High-Multiplicity HE Muon Bundle In InIce / DeepCore Color: Time Muon energy estimated from sum of DOM signals Patrick Berghaus 21 Cosmic Rays in IceCube

DOM Waveforms Shower Core 500 pe High-p t Scattered muons Photons 400 ns DOM readout triggered by outlying muons: Characteristic for large CR bundles Patrick Berghaus 22 Cosmic Rays in IceCube

IceTop/InIce Energy Correlation <log A> = He PRELIMINARY at E prim ≈ 10PeV InIce (HE muons) <Q MC (A)> = <Q data > IceTop (EM) Patrick Berghaus 23 Cosmic Rays in IceCube

Seasonal Variations Atmospheric Temperature IceTop ( barometric ) ≈ 20% InIce ( temperature ) T eff : Temperature weighted by muon production probability Patrick Berghaus 24 S. Tilav et al., arXiv:1001.0776 Cosmic Rays in IceCube

First Extraterrestrial IceCube Signal 13 Dec. 2006: Solar Flare seen in IceTop Count Rate Patrick Berghaus 25 Cosmic Rays in IceCube

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