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Atmospheric Neutrinos. Stefan Söldner-Rembold University of Manchester 19 Decembe r 2013. Atmospheric Neutrinos . Provide complementary results with other neutrino sources. Increase precision of global fits of neutrino parameters. Tools to search for new physics. Three Questions.
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Atmospheric Neutrinos Stefan Söldner-Rembold University of Manchester 19 December 2013
Atmospheric Neutrinos • Provide complementary results with other neutrino sources. • Increase precision of global fits of neutrino parameters. • Tools to search for new physics. NuPhys 2013 - Söldner-Rembold
Three Questions arXiv:1312.2878, see talk by E. Lisi Is θ23 mixing maximal and which is the right octant ? Is the mass hierarchy normal or inverted ? 3) Is δCP > 0 ? NuPhys 2013 - Söldner-Rembold
Neutrino Propagation in the Earth ν ν ν Preliminary Reference Earth Model Atmospheric neutrinos interact with Earth’s mantle and core. - MSW effect alters oscillation properties (energy, electron density, MH and flavour dependent). - “parametric enhancement” at Core/Mantle interface. NuPhys 2013 - Söldner-Rembold
MSW Effect +: neutrinos -: anti-neutrinos CC interactions Effective mixing angle in matter: Resonance condition for - neutrinos in normal hierarchy. - anti-neutrinos in inverted hierarchy. depends on energy and density profile. NuPhys 2013 - Söldner-Rembold
MSW Effect in the Earth SK cosθ cosθ Energy Energy Distortions for cosθ < -0.5 and at 10 GeV caused by MSW effect arXiv:1310.6677 NuPhys 2013 - Söldner-Rembold
Neutrino Energies 10 MeV 100 MeV 1 GeV 10 GeV 100 GeV 1 TeV 10 TeV 100 TeV 1 PeV 10 PeV Super-K Deep Core IceCube ANITA PINGU Borexino KamLAND Double Chooz Daya Bay SNO Fill gap in intermediate energy region in region of MSW resonance effects. Several future experiments: INO, PINGU, Hyper-K, LBNE.. NuPhys 2013 - Söldner-Rembold
Super-Kamiokande Water Cherenkov Detector located in Mozumi Mine, Kamioka, Japan 50,000t of water 11,146 PMTs First observation of muon-neutrino deficit due to oscillations in 1993 NuPhys 2013 - Söldner-Rembold
Super-Kamiokande (SKI-IV) red: un-oscillated blue: best oscillation fit NuPhys 2013 - Söldner-Rembold
ντ Appearance (SK) Phys. Rev. Lett. 110, 181802 (2013) fitted signal in grey Unambiguous evidence for oscillations (νμντ) since not present in source. 2806 day running period. Energy threshold E > 3.5 GeV. Reconstruct hadronic tau decays using neural network. 3.8 standard deviation significance (complements OPERA result) NuPhys 2013 - Söldner-Rembold
MINOS see presentation by C. Backhouse 5,400 ton Far Detector Alternating layers of steel calorimeter and plastic scintillator. Magnetized for charge identification NuPhys 2013 - Söldner-Rembold
MINOS Beam/Atmospheric Data NuPhys 2013 - Söldner-Rembold
MINOS Combined Analysis NuPhys 2013 - Söldner-Rembold
Future Experiments NuPhys 2013 - Söldner-Rembold
Indian Neutrino Observatory Located in Madurai City, Tamil Nadu NuPhys 2013 - Söldner-Rembold
ICAL@INO Iron sampling calorimeter (ICAL) with Resistive Plate Chamber (RPCs) as active component. 50,000 t of iron. 1.3-1.5 T magnetic field for charge identification and momentum reconstruction Pre-project activities approved. NuPhys 2013 - Söldner-Rembold
INO Sensitivity arXiv: 1303.2534 sin2 2θ13= 0.12, 0.1, 0.08 and sin2θ23= 0.5. NuPhys 2013 - Söldner-Rembold
PINGU Extension of IceCube located at the South Pole. 40 strings with 60 PINGU Digital Optical Modules (PDOMs) per string. Design still being optimised. In-fills DeepCore in clearest ice at bottom centre of IceCube. Effective mass about 3Mt for energies > 5 GeV NuPhys 2013 - Söldner-Rembold
PINGU μ direction 4.4 GeVνµ Nγ: circle size tγ: colour PINGU Digital Optical Module: HQE PMT, electronics, pressure vessel. Very similar to IceCube DOM. NuPhys 2013 - Söldner-Rembold
MH Signature Need good energy and angular resolution. Energy + = Pattern A NH IH + = Pattern B cos(θ) Diagonals are lines of constant L/E NuPhys 2013 - Söldner-Rembold
“Distinguishability” Parametrized reconstruction, PID: cascades Parametrized reconstruction, PID: tracks With realistic particle identification No systematics NuPhys 2013 - Söldner-Rembold
PINGU Consistent results from different statistical techniques, includes systematics (mainly energy scale, cross sections). First vs second octant First octant only Expect 1.75 standard deviations after first year of data. Reach 3 standard deviations in roughly 3 years. PINGU currently being considered by P5 in the US – will possibly be part of a larger NSF facility at South Pole. NuPhys 2013 - Söldner-Rembold
KM3NeT/ORCA • 1000 optical moduleswith 6 m spacing, over 50 strings. • Semi random pattern in a circular footprint. • Mean distance between strings is 20 m. • - Instrumented volume: 1.8 Mton not being pursued ? NuPhys 2013 - Söldner-Rembold
LBNE LBNE Far Detector needs to be underground for atmospheric neutrino detection. see talk by R. Wilson Data taking to start around 2025 Liquid Argon TPC ArgoNeuT NuPhys 2013 - Söldner-Rembold
LBNE 35 kt x 10 yrs = 350 kt-yrs arXiv:1307.7335 NuPhys 2013 - Söldner-Rembold
LBNE arXiv:1307.7335 NuPhys 2013 - Söldner-Rembold
Hyper-Kamiokande arXiv:1109.3262 8 km south of SK Total mass: 1 Mt Fiducial mass: 560 kt (25 times SK) 99,000 inner detector PMTs (20’’) Data taking expected to start 2023 NuPhys 2013 - Söldner-Rembold
Sensitivity to Mass Hierarchy 10 years of data Lowest sensitivity for first octant. arXiv:1309.0184 NuPhys 2013 - Söldner-Rembold
Sensitivity to θ23 Octant 10 years of data NuPhys 2013 - Söldner-Rembold
Mass Hierarchy Bottom Line arXiv:1311.1822 plus Hyper-K with > 3 sigma around 2033. NuPhys 2013 - Söldner-Rembold
Summary • Atmospheric neutrinos are a unique source of information, • complementary to neutrino long-baseline beam results. • Several next-generation experiments based on (frozen) water • (PINGU, Hyper-K), liquid argon (LBNE) or iron sampling • calorimeters (INO) are currently being designed. • These experiments have potential to determine neutrino mass • hierarchy and to constrain θ23 , providing, among others, • important input for δCP determinations. NuPhys 2013 - Söldner-Rembold