Neutrino A Astrophys ysics cs: C Challenges a and P - PowerPoint PPT Presentation

Neutrino A Astrophys ysics cs: C Challenges a and P Possibilities Sovan C Chakraborty y MPI for Physics, Munich Institute of Physics, Bhubaneswar

NEUTRINOS • Chargeless • Spin ½ • Weakly interacting • Almost massless Ne Neutr trin inos have have a a tin tiny bu but f finite m mass Neutrino o osci cillations No bending in magnetic fields è Point back to the source Minimal obstruction / scattering è Arrive directly from regions opaque to light.

NEUTRINO SOURCES

NEUTRINO SOURCE SPECTRA

NEUTRINOS FROM SUN Solar Radiation: 98% light, 2% neutrinos Thermonuclear Reaction Chain 1938 66 billion neutrinos/cm 2 sec 1-10 MeV

NEUTRINOS DETECTION Neutrino Detection (1954-1956) Reactor Anti-Electron Neutrinos were detected Clyde Cowan and Fred Reines Fred Reines (1918-1998), Nobel Prize 1995

NEUTRINOS FROM SUN Solar Neutrino Detection Ray Da y Davis J Jr. ( (1914–2006) Homestake Solar neutrino Observatory Masatoshi Ko Koshiba ( (*1926) (1967-2002) Nobel Prize 2002 for Neutrino Inverse Beta Decay on Chlorine Astronomy

SOLAR NEUTRINO PUZZLE Expectation Observation Solar Neutrino Detection Ray Davis Jr. (1914–2006) Masatoshi Koshiba (*1926) Homestake Solar neutrino Observatory (1967-2002) Nobel P Prize 2 2002 f for N Neutrino Inverse Beta Decay on Chlorine Astronomy y

ATMOSPHERIC NEUTRINO PUZZLE Solution : Neutrino flavor oscillations

NEUTRINO FLAVOR OSCILLATIONS cos sin ν ⎛ ⎞ θ θ ν ⎛ ⎞ ⎛ ⎞ e 1 Two flavor mixing = ⎜ ⎟ ⎜ ⎟ ⎜ ⎟ sin cos ν − θ θ ν ⎝ ⎠⎝ ⎠ ⎝ ⎠ 2 µ 2 m 2 2 p E m E i Each mass eigenstates propagates as e ipz with = − ≈ − i 2 E ip z -ip z ( ) z sin e cos e − ν = − θ 1 ν + θ 2 ν 1 2 µ 2 m L ⎛ ⎞ 2 Δ 2 2 P ( ) ( ) z (0) sin 2 sin 2 ν oscillation probability ν → ν = ν ν = θ ⎜ ⎟ e e µ µ 4 E ⎝ ⎠

ATMOSPHERIC NEUTRINO PUZZLE Solution : Neutrino flavor oscillations ν μ and ν τ mix Measure

SOLAR NEUTRINO PUZZLE Expectation Observation Solution : Neutrino flavor oscillations in matter ν e mixes with other flavors. Resonance mixing inside the Sun Measure

RREACTOR AND GEO NEUTRINO Reactor Neutrinos: Confirmed oscillations through solar neutrino parameters even in vacuum Measure Geo Neutrinos: Produced by natural radioactivity in Earth’s crust KamLAND, Borexino Useful for understanding Earth’s radioactivity Neutrino Geophysics!!

3 ν ¡FRAMEWORK ¡and ¡OPEN ¡QUESTIONS ¡ Mixing parameters: U = U ( θ 12 , θ 13 , θ 23 , δ ) ¡ i 1 c e s c s − δ ⎛ ⎞ ν ν ⎛ ⎞ ⎛ ⎞ ⎛ ⎞⎛ ⎞ c 12 = ¡cos ¡ θ 12 , ¡etc., ¡ ¡ e 13 13 12 12 1 ⎜ ⎟ ⎜ ⎟ ⎜ ⎟ ⎜ ⎟⎜ ⎟ c s 1 s c ν = − ν ⎜ ⎟ δ ¡CP ¡phase ¡ ¡ ⎜ ⎟ ⎜ 23 23 ⎟ ⎜ 12 12 ⎟⎜ 2 ⎟ µ ⎜ ⎟ ⎜ ⎟ ⎜ ⎟⎜ ⎟ ⎜ i ⎟ s c e s c 1 − δ ν − − ν ⎝ ⎠ ⎝ ⎠ ⎝ ⎠⎝ ⎠ ⎝ ⎠ 23 23 13 13 3 τ δ m 2 ¡ δ m 2 ¡ M 2 = - , + , ± Δ m 2 ¡ Mass-gap parameters: ¡ ¡ ¡ 2 2 “ solar ” � “ atmospheric ” �

3 ν ¡FRAMEWORK ¡and ¡OPEN ¡QUESTIONS ¡ δ m 2 ¡ δ m 2 ¡ M 2 = - , + , ± Δ m 2 ¡ Mass-gap parameters: ¡ ¡ ¡ 2 2 “ solar ” � “ atmospheric ” � Mass Ordering: Normal vs Inverted

Neutrinos from Supernovae Sanduleak - 69 202 Supernova 1987A 23 February 1987

…but ¡about ¡two ¡hours ¡before: ¡ Kamiokande-II (Japan) Water Cherenkov detector 2140 tons Clock uncertainty ± 1 min Irvine-Michigan-Brookhaven (US) Water Cherenkov detector 6800 tons Clock uncertainty ± 50 ms Baksan Scintillator Telescope (Soviet Union), 200 tons Random event cluster ~ 0.7/day Clock uncertainty +2/-54 s The ¡core ¡collapse ¡and ¡ ν ¡cooling ¡mechanism ¡confirmed! ¡

Stellar Collapse and Core-Collapse Supernova Main-sequence star Helium-burning star Hydrogen Burning Helium Hydrogen Burning Burning [slides from G. Raffelt]

Stellar Collapse and Core-Collapse Supernova Onion structure Collapse (implosion) [slides from G. Raffelt]

Stellar Collapse and Core-Collapse Supernova Collapse (implosion)

Stellar Collapse and Core-Collapse Supernova Collapse (implosion)

Stellar Collapse and Core-Collapse Supernova Newborn Neutron Star Collapse (implosion) ~ 50 km Neutrino Cooling Proto-Neutron Star ρ ≈ ρ nuc = 3 × 10 14 g cm - 3 T ≈ 30 MeV

Stellar Collapse and Core-Collapse Supernova Newborn Neutron Star ~ 50 km ENERGY SCALE: 99% energy (10 53 ergs ) is emitted by neutrinos (Energy ~ 10 MeV). TIME SCALE: Neutrino Cooling The duration of the burst lasts ~10s. Proto-Neutron Star ρ ≈ ρ nuc = 3 × 10 14 g cm - 3 T ≈ 30 MeV

Shock Revival by Neutrinos Shock receive fresh energy from neutrinos!! Delayed Mechanism

Growing S Set o of 2 2D Ex D Exploding M Models Realistic neutrino transport, convection and turbulence, hydrodynamical instabilities (SASI). Hanke et al, 1303.6269

Failed Ex Explosion Tamborra ¡et ¡al., ¡arXiv:1402.5418 ¡

Status of SN Explosion • Standard paradigm for many years: Neutrino-driven explosion (delayed explosion, Wilson mechanism) • Numerical explosions ok for small-mass progenitors in 1D (spherical symmetry) • Numerical explosions ok for broad mass range in 2D (axial symmetry) • 3D studies only beginning – no clear picture yet Better spatial resolution needed?

Sky M y Map o of L Lepton-N -Number F Flux ( (11.2 M M SUN SUN M Model) — ( 𝝃 𝒇 − 𝝃 𝒇 ) r Lepton-n -number f flux ( relative t to 4 4 π average average De Deleptonization f flux i into o one h hemisphere, r roughly d y dipole d distribution (LES ESA — — L Lepton Em Emission S Self-S -Sustained A Asym ymmetry) y) Tamborra ¡et ¡al., ¡arXiv:1402.5418 ¡

LESA Schematic Description Accre&on ¡flow ¡ Tamborra ¡et ¡al., ¡ ¡arXiv:1402.5418 ¡

Neutrino Average Energy Accre&on ¡ powered by infalling • matter Stalled shock • Flavor Oscillation can Accretion: ~ 0.5 s — give harder 𝝃 𝒇 and 𝝃 𝒇 and 𝝃 𝒇 spectra 𝝃 μ , τ — 𝝃 𝒇 𝝃 𝒇 [Fischer et al. (Basel Simulations), A&A 517:A80,2010, 10. 8 M sun progenitor mass]

Neutrino Emission Phases Accre&on ¡ powered by infalling • matter Stalled shock • Flavor Oscillation can Accretion: ~ 0.5 s — give harder 𝝃 𝒇 and 𝝃 𝒇 and 𝝃 𝒇 spectra 𝝃 μ , τ Instabilities in neutrino — 𝝃 𝒇 evolution due to Neutrino-Neutrino interaction 𝝃 𝒇 EXTRA Heating??? [Fischer et al. (Basel Simulations), A&A 517:A80,2010, 10. 8 M sun progenitor mass]

Stability A y Analys ysis 10.8 Solar Mass, 225 ms Basel simulation 225 ms 1000 SN density profile crossing the 100 λ (km -1 ) instability zone may trigger 10 flavor conversion 1 0.1 100 150 200 300 500 700 1000 1500 2000 Radius (km) S.C , Mirizzi, Saviano & Seixas PRD, 2014

LESA Schematic Description LESA lepton asymmetry Large lepton asymmetry prohibits instability in neutrino evolution S.C , Raffelt, Janka & Mueller, arXiv:1412.0670

Stability A y Analys ysis: L LES ESA Minimum lepton Asymmetry Maximum lepton Asymmetry 10 4 10 4 Ε � � 0.05 Ε � 0.5 1000 1000 Ε � 0.00 Ε � 1.0 Ε � 0.05 Λ � km � 1 � 100 Ε � 1.5 Λ � km � 1 � 100 Ε � 0.20 10 10 1 1 0.1 0.1 100 150 200 300 500 700 1000 1500 100 150 200 300 500 700 1000 1500 Radius � km � Radius � km � S.C , Raffelt, Janka & Mueller, arXiv:1412.0670

Stability A y Analys ysis: L LES ESA Minimum lepton Asymmetry 10 4 Ε � � 0.05 1000 0.00 Ε � 0.05 Λ � km � 1 � 100 Ε � 0.20 Ε � 10 1 0.1 100 150 200 300 500 700 1000 1500 Radius � km �

High Energy Neutrinos

South Pole (completed in 201

What do we know? South Pole (completed in 201

Background and Signals Atmospheric neutrino & muon production in cosmic ray air showers. Muons are absorbed inside the Earth. Only events from above. Atmospheric neutrino background From North and South. Earth becomes opaque to high-energy neutrinos! PeV events are coming from above.

� � � � � � � � Event classes in IceCube Tracks Cascades muon cascade ta) ta) Source: � Source: � ν e , ν µ , ν τ NC + ν e CC interaction � ν µ CC interaction � Limited angular resolution ( ≳ 10°) � Good angular resolution (<1°) � Good energy resolution � Moderate energy resolution �

PeV Events in IceCube • Shown at Neutrino’12 • Both downgoing cascades • Expected background: 0.082 January 3rd, 2012 August 9th, 2011 1 . 14 ± 0 . 17 PeV 1 . 04 ± 0 . 16 PeV IceCube Collaboration, PRL 111, 021103(2013)