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SN 1006

SN 1006. 25 ème Journée Thématique de l’IPN, 3 Juin 2008, Orsay. Frontiers of Low-Energy Neutrino Astronomy: Earth, Sun and Supernovae. Georg Raffelt, Max-Planck-Institut für Physik, München. Where do Neutrinos Appear in Nature?. Nuclear Reactors. . Sun. . Supernovae

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SN 1006

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  1. SN 1006 25ème Journée Thématique de l’IPN, 3 Juin 2008, Orsay Frontiers of Low-Energy Neutrino Astronomy: Earth, Sun and Supernovae Georg Raffelt, Max-Planck-Institut für Physik, München

  2. Where do Neutrinos Appear in Nature? Nuclear Reactors  Sun  Supernovae (Stellar Collapse) Particle Accelerators  SN 1987A Earth Atmosphere (Cosmic Rays)  Astrophysical Accelerators Soon ? Earth Crust (Natural Radioactivity)  Cosmic Big Bang (Today 330 n/cm3) Indirect Evidence

  3. Where do Neutrinos Appear in Nature? Neutrinos from nuclear reactions: Energies 1-20 MeV Quasi thermal sources Supernova: T ~ few MeV Big-Bang Neutrinos: Very small energies today (cosmic red shift) Like matter today • “Beam dump neutrinos” • High-energy protons hit • matter or photons • Produce secondary p • Neutrinos from pion • decay • p  m + nm • me + nm+ne • Energies ≫ GeV

  4. Where do Neutrinos Appear in Nature? Low-energy neutrino astronomy (including geo-neutrinos) Energies ~ 1-50 MeV • Long-baseline • neutrino oscillation • experiments with • Reactor neutrinos • Neutrino beams from • accelerators High-energy neutrino astronomy Closely related to cosmic-ray physics

  5. Neutrinos from the Sun Hans Bethe (1906-2005, Nobel prize 1967) Thermonuclear reaction chains (1938) Helium Reaction- chains Energy 26.7 MeV Solar radiation: 98 % light 2 % neutrinos At Earth 66 billion neutrinos/cm2 sec

  6. Bethe’s Classic Paper on Nuclear Reactions in Stars No neutrinos from nuclear reactions in 1938 …

  7. Gamow & Schoenberg, Phys. Rev. 58:1117 (1940)

  8. Sun Glasses for Neutrinos? 8.3 light minutes Several light years of lead needed to shield solar neutrinos Bethe & Peierls 1934: “… this evidently means that one will never be able to observe a neutrino.”

  9. First Detection (1954 -1956) Anti-Electron Neutrinos from Hanford Nuclear Reactor 3 Gammas in coincidence n Cd p e+ e- g g g Clyde Cowan (1919 – 1974) Fred Reines (1918 – 1998) Nobel prize 1995 Detector prototype

  10. First Measurement of Solar Neutrinos Inverse beta decay of chlorine 600 tons of Perchloroethylene Homestake solar neutrino observatory (1967-2002)

  11. Cherenkov Effect Light Electron or Muon (Charged Particle) Neutrino Light Cherenkov Ring Georg Raffelt, Max-Planck-Institut für Physik, München 25ème Journée Thématique de l’IPN, 3 Juin 2008, Orsay Elastic scattering or CC reaction Water

  12. Super-Kamiokande: Sun in the Light of Neutrinos Georg Raffelt, Max-Planck-Institut für Physik, München 25ème Journée Thématique de l’IPN, 3 Juin 2008, Orsay

  13. 2002 Physics Nobel Prize for Neutrino Astronomy Ray Davis Jr. (1914 - 2006) Masatoshi Koshiba (*1926) “for pioneering contributions to astrophysics, in particular for the detection of cosmic neutrinos”

  14. Missing Neutrinos from the Sun Homestake Chlorine 8B Calculation of expected experimental counting rate from various source reactions CNO 7Be Measurement (1970–1995) John Bahcall 1934 - 2005 Raymond Davis Jr. 1914 - 2006

  15. Neutrino Flavor Oscillations Two-flavor mixing Each mass eigenstate propagates as with Phase difference implies flavor oscillations Probabilitynenm sin2(2q) Bruno Pontecorvo (1913 – 1993) Invented nu oscillations z Oscillation Length

  16. Missing Neutrinos from the Sun Electron-Neutrino Detectors All Flavors Water Water Heavy Water Heavy Water Chlorine Gallium ne+e- ne+e- n+ e- n+ e- ne+dp+p+e- n+dp+n+n 8B 8B 8B 8B 8B 8B CNO 7Be pp CNO 7Be Homestake Gallex/GNO SAGE (Super-) Kamiokande SNO SNO

  17. Three-Flavor Neutrino Parameters Atmospheric/K2K CHOOZ Solar/KamLAND 2s ranges hep-ph/0405172 Solar 75-92 Atmospheric 1400-3000 d CP-violating phase Normal Inverted 2 3 e e m m t t Sun Atmosphere 1 e e m m t t m m t t Atmosphere 2 Sun 1 3 • Tasks and Open Questions • Precision for q12 andq23 • How large is q13? • CP-violating phase d? • Mass ordering? • (normal vs inverted) • Absolute masses? • (hierarchical vs degenerate) • Dirac or Majorana?

  18. Solar Neutrino Spectrum 7-Be line measured by Borexino (2007)

  19. Solar Neutrino Spectroscopy with BOREXINO • Neutrino electron scattering • Liquid scintillator technology • (~ 300 tons) • Low energy threshold • (~ 60 keV) • Online since 16 May 2007 • Expected without flavor oscillations 75 ± 4 counts/100t/d • Expected with oscillations 49 ± 4 counts/100t/d • BOREXINO result (May 2008) 49 ± 3stat ± 4syscnts/100t/d arXiv:0805.3843 (25 May 2008) Georg Raffelt, Max-Planck-Institut für Physik, München 25ème Journée Thématique de l’IPN, 3 Juin 2008, Orsay

  20. Next Steps in Borexino • Collect more statistics of Beryllium line • Seasonal variation of rate • (Earth orbit eccentricity) • Measure neutrinos from the CNO reaction chain • Information about solar metal abundance Measure geo-neutrinos (from natural radioactivity in the Earth crust) Approx. 7-17 events/year Main background: Reactors ~ 20 events/year

  21. Geo Neutrinos: Why and What? • We know surprisingly little about • the interior of the Earth: • Deepest bore hole ~ 12 km • Samples from the crust are • available for chemical analysis • (e.g. vulcanoes) • Seismology reconstructs density • profile throughout the Earth • Heat flow from measured • temperature gradients 30-44 TW • (BSE canonical model, based on • cosmochemical arguments, • predicts ~ 19 TW from crust and • mantle, none from core) • Neutrinos escape freely • Carry information about chemical composition, radioactive heat production, • or even a putative natural reactor at the core

  22. Expected Geo Neutrino Fluxes S. Dye, Talk 5/25/2006 Baltimore

  23. Geo Neutrinos Predicted geo neutrino flux KamLAND scintillator detector (1 kton) Reactor background

  24. Kamland Observation of Geoneutrinos • First tentative observation of geoneutrinos • at Kamland in 2005 (~ 2 sigma effect) • Very difficult because of large background • of reactor neutrinos • (is main purpose for neutrino oscillations)

  25. Sanduleak -69 202 Supernova 1987A23 February 1987 Tarantula Nebula Large Magellanic Cloud Distance 50 kpc (160.000 light years) Georg Raffelt, Max-Planck-Institut für Physik, München 25ème Journée Thématique de l’IPN, 3 Juin 2008, Orsay

  26. Supernova Neutrinos 20 Jahre nach SN 1987A Georg Raffelt, Max-Planck-Institut für Physik, München 25ème Journée Thématique de l’IPN, 3 Juin 2008, Orsay

  27. Stellar Collapse and Supernova Explosion Main-sequence star Onion structure Helium-burning star Collapse (implosion) Hydrogen Burning Helium Burning Hydrogen Burning Degenerate iron core: r 109 g cm-3 T  1010 K MFe 1.5 Msun RFe 8000 km

  28. Stellar Collapse and Supernova Explosion Newborn Neutron Star Collapse (implosion) Explosion ~ 50 km Neutrino Cooling Proto-Neutron Star r  rnuc= 31014 g cm-3 T  30 MeV

  29. Stellar Collapse and Supernova Explosion Newborn Neutron Star ~ 50 km Gravitational binding energy Eb 3  1053 erg  17% MSUN c2 This shows up as 99% Neutrinos 1% Kinetic energy of explosion (1% of this into cosmic rays) 0.01% Photons, outshine host galaxy Neutrino Cooling Neutrino luminosity Ln 3  1053 erg / 3 sec  3  1019LSUN While it lasts, outshines the entire visible universe Proto-Neutron Star r  rnuc= 31014 g cm-3 T  30 MeV

  30. Neutrino Signal of Supernova 1987A 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 Within clock uncertainties, signals are contemporaneous

  31. The Energy-Loss Argument SN 1987A neutrino signal Volume emission of novel particles Emission of very weakly interacting particles would “steal” energy from the neutrino burst and shorten it. (Early neutrino burst powered by accretion, not sensitive to volume energy loss.) Neutrino diffusion Late-time signal most sensitive observable Neutrino sphere

  32. Do Neutrinos Gravitate? Neutrinos arrive a few hours earlier than photons  Early warning (SNEWS) SN 1987A: Transit time for photons and neutrinos equal to within ~ 3h Shapiro time delay for particles moving in a gravitational potential Longo, PRL 60:173,1988 Krauss & Tremaine, PRL 60:176,1988 Equal within ~ 1 - 4 10-3 • Proves directly that neutrinos respond to gravity in the usual way • because for photons gravitational lensing already proves this point • Cosmological limits DNn≲ 1 much worse test of neutrino gravitation • Provides limits on parameters of certain non-GR theories of gravitation

  33. Neutrino-Driven Delayed Explosion Neutrino heating increases pressure behind shock front Picture adapted from Janka, astro-ph/0008432

  34. Standing Accretion Shock Instability (SASI) Georg Raffelt, Max-Planck-Institut für Physik, München 25ème Journée Thématique de l’IPN, 3 Juin 2008, Orsay Mezzacappa et al., http://www.phy.ornl.gov/tsi/pages/simulations.html

  35. Large Detectors for Supernova Neutrinos LVD (400) Borexino (100) Baksan (100) Super-Kamiokande (104) KamLAND (400) MiniBooNE (200) In brackets events for a “fiducial SN” at distance 10 kpc IceCube (106)

  36. Simulated Supernova Signal at Super-Kamiokande Accretion Phase Kelvin-Helmholtz Cooling Phase Simulation for Super-Kamiokande SN signal at 10 kpc, based on a numerical Livermore model [Totani, Sato, Dalhed & Wilson, ApJ 496 (1998) 216]

  37. IceCube Neutrino Telescope at the South Pole • 1 km3 antarctic ice, instrumented • with 4800 photomultipliers • 40 of 80 strings installed (2008) • Completion until 2011 foreseen

  38. IceCube as a Supernova Neutrino Detector Each optical module (OM) picks up Cherenkov light from its neighborhood. SN appears as “correlated noise”. • About 300 • Cherenkov • photons • per OM • from a SN • at 10 kpc • Noise • per OM • < 260 Hz • Total of • 4800 OMs • in IceCube IceCube SN signal at 10 kpc, based on a numerical Livermore model [Dighe, Keil & Raffelt, hep-ph/0303210] • Method first discussed by • Pryor, Roos & Webster, • ApJ 329:355 (1988) • Halzen, Jacobsen & Zas • astro-ph/9512080

  39. Neutrino Oscillations in Matter Neutrinos in a medium suffer flavor-dependent refraction (PRD 17:2369, 1978) f W, Z Z f n n n n Lincoln Wolfenstein • “Level crossing” possible in a medium with a gradient (MSW effect) • - For solar nus large flavor conversion anyway due to large mixing • - Still important for 13-oscillations in supernova envelope • Breaks degeneracy between Q and p/2 -Q(dark vs light side) • - 12 mass ordering for solar nus established • - 13 mass ordering (normal vs inverted) at future LBL or SN • Discriminates against sterile nus in atmospheric oscillations • CP asymmetry in LBL, to be distinguished from intrinsic CP violation • Prevents flavor conversion in a SN core and within shock wave • Strongly affects sterile nu production in SN or early universe

  40. H- and L-Resonance for MSW Oscillations R. Tomàs, M. Kachelriess, G. Raffelt, A. Dighe, H.-T. Janka & L. Scheck: Neutrino signatures of supernova forward and reverse shock propagation[astro-ph/0407132] Resonance density for Resonance density for

  41. Shock-Wave Propagation in IceCube Inverted Hierarchy No shockwave Inverted Hierarchy Forward & reverse shock Inverted Hierarchy Forward shock Normal Hierarchy Choubey, Harries & Ross, “Probing neutrino oscillations from supernovae shock waves via the IceCube detector”, astro-ph/0604300

  42. Collective Effects in Neutrino Flavor Oscillations • Collapsed supernova core or accretion torus of • merging neutron stars: • Neutrino flux very dense: Up to 1035 cm-3 • Neutrino-neutrino interaction energy • much larger than vacuum oscillation frequency • Large “matter effect” of neutrinos on each • other • Non-linear oscillation effects • Assume 80% anti-neutrinos • Vacuum oscillation frequency • w = 0.3 km-1 • Neutrino-neutrino interaction • energy at nu sphere (r = 10 km) • m = 0.3105 km-1 • Falls off approximately as r-4 • (geometric flux dilution and nus • become more co-linear)

  43. Spectral Split (Stepwise Spectral Swapping) Initial fluxes at nu sphere After collective trans- formation For explanation see Raffelt & Smirnov arXiv:0705.1830 arXiv:0709.4641 Duan, Fuller, Carlson & Qian arXiv:0706.4293 arXiv:0707.0290 Fogli, Lisi, Marrone & Mirizzi, arXiv:0707.1998

  44. Mass Hierarchy at Extremely Small Theta-13 Using Earth matter effects to diagnose transformations Ratio of spectra in two water Cherenkov detectors (0.4 Mton), one shadowed by the Earth, the other not Dasgupta, Dighe & Mirizzi, arXiv:0802.1481

  45. Collective SN neutrino oscillations 2006-2008 (I) “Bipolar” collective transformations important, even for dense matter • Duan, Fuller & Qian • astro-ph/0511275 • Numerical simulations • Including multi-angle effects • Discovery of “spectral splits” • Duan, Fuller, Carlson & Qian • astro-ph/0606616, 0608050 • Pendulum in flavor space • Collective pair annihilation • Pure precession mode • Hannestad, Raffelt, Sigl & Wong • astro-ph/0608695 • Duan, Fuller, Carlson & Qian • astro-ph/0703776 Self-maintained coherence vs. self-induced decoherence caused by multi-angle effects • Sawyer, hep-ph/0408265, 0503013 • Raffelt & Sigl, hep-ph/0701182 • Esteban-Pretel, Pastor, Tomàs, • Raffelt & Sigl, arXiv:0706.2498 Theory of “spectral splits” in terms of adiabatic evolution in rotating frame • Raffelt & Smirnov, • arXiv:0705.1830, 0709.4641 • Duan, Fuller, Carlson & Qian • arXiv:0706.4293, 0707.0290 Independent numerical simulations • Fogli, Lisi, Marrone & Mirizzi • arXiv:0707.1998

  46. Collective SN neutrino oscillations 2006-2008 (II) Three-flavor effects in O-Ne-Mg SNe on neutronization burst (MSW-prepared spectral double split) • Duan, Fuller, Carlson & Qian, • arXiv:0710.1271 • Dasgupta, Dighe, Mirrizzi & Raffelt, • arXiv:0801.1660 Theory of three-flavor collective oscillations • Dasgupta & Dighe, • arXiv:0712.3798 Second-order mu-tau refractive effect important in three-flavor context • Esteban-Pretel, Pastor, Tomàs, • Raffelt & Sigl, arXiv:0712.1137 Identifying the neutrino mass hierarchy at extremely small Theta-13 • Dasgupta, Dighe & Mirizzi, • arXiv:0802.1481 Formulation for non-spherical geometry • Dasgupta, Dighe, Mirizzi & Raffelt • arXiv:0805.3300 Many theoretical questions for this neutrino many-body system remain unresolved!

  47. Core-Collapse SN Rate in the Milky Way Core-collapse SNe per century 7 8 0 1 2 3 4 5 6 9 10 SN statistics in external galaxies van den Bergh & McClure (1994) Cappellaro & Turatto (2000) Gamma rays from 26Al (Milky Way) Diehl et al. (2006) Historical galactic SNe (all types) Strom (1994) Tammann et al. (1994) No galactic neutrino burst 90 % CL (25 y obserservation) Alekseev et al. (1993) References: van den Bergh & McClure, ApJ 425 (1994) 205. Cappellaro & Turatto, astro-ph/0012455. Diehl et al., Nature 439 (2006) 45. Strom, Astron. Astrophys. 288 (1994) L1. Tammann et al., ApJ 92 (1994) 487. Alekeseev et al., JETP 77 (1993) 339 and my update.

  48. SuperNova Early Warning System (SNEWS) Neutrino observation can alert astronomers several hours in advance to a supernova. To avoid false alarms, require alarm from at least two experiments. Super-K IceCube Coincidence Server @ BNL Alert LVD Supernova 1987A Early Light Curve Others ? http://snews.bnl.gov astro-ph/0406214

  49. Experimental Limits on Relic Supernova Neutrinos Super-K upper limit 29 cm-2 s-1 for Kaplinghat et al. spectrum [hep-ex/0209028] Upper-limit flux of Kaplinghat et al., astro-ph/9912391 Integrated 54 cm-2 s-1 Cline, astro-ph/0103138

  50. DSNB Measurement with Neutron Tagging Beacom & Vagins, hep-ph/0309300 [Phys. Rev. Lett., 93:171101, 2004] Future large-scale scintillator detectors (e.g. LENA with 50 kt) • Inverse beta decay reaction tagged • Location with smaller reactor flux • (e.g. Pyhäsalmi in Finland) could • allow for lower threshold Pushing the boundaries of neutrino astronomy to cosmological distances

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