Physik Kolloquium, 19. November 2007 RWTH Aachen

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1 Physik Kolloquium, 19. November 2007 RWTH Aachen
Title Physik Kolloquium, 19. November 2007 RWTH Aachen Exzellenz Georg Raffelt, Max-Planck-Institut für Physik, München

2 Supernova Neutrinos 20 Years after SN 1987A
Aachen Skyline Supernova Neutrinos 20 Years after SN 1987A

3 Sanduleak -69 202 Supernova 1987A 23 February 1987 Tarantula Nebula
Large Magellanic Cloud Distance 50 kpc ( light years) Georg Raffelt, Max-Planck-Institut für Physik, München Physik Kolloquium, 19. November 2007, RWTH Aachen

4 Supernova Neutrinos 20 Jahre nach SN 1987A
Georg Raffelt, Max-Planck-Institut für Physik, München Physik Kolloquium, 19. November 2007, RWTH Aachen

5 Crab Nebula Georg Raffelt, Max-Planck-Institut für Physik, München
Physik Kolloquium, 19. November 2007, RWTH Aachen

6 Supernova 1054 Petrograph Hand signifies sacred place Crescent SN 1054
Moon 3 concentric circles, diameter  1 foot, with huge red flames trailing to the right. (Halley’s Comet ?) SN 1054 Hand signifies sacred place Possible SN 1054 Petrograph by the Anasazi people (Chaco Canyon, New Mexico)

7 SN 1987A Rings (Hubble Space Telescope 4/1994)
Georg Raffelt, Max-Planck-Institut für Physik, München, Germany SN 1987A Rings (Hubble Space Telescope 4/1994) 500 Light-days Ring system consists of material ejected from the progenitor star, illuminated by UV flash from SN 1987A Foreground Star Supernova Remnant (SNR) 1987A

8 SN 1987A Explosion Hits Inner Ring

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

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

11 Stellar Collapse and Supernova Explosion
Newborn Neutron Star ~ 50 km Proto-Neutron Star r  rnuc = 3  g cm-3 T  30 MeV Neutrino Cooling 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 luminosity Ln  3  1053 erg / 3 sec  3  1019 LSUN While it lasts, outshines the entire visible universe

12 Periodic System of Elementary Particles
Quarks Leptons Charm Top Gravitation Weak Interaction Strong Interaction (QCD) Electromagnetic Interaction (QED) Down Strange Bottom Electron Muon Tau e-Neutrino t-Neutrino 1st Family 2nd Family 3rd Family Charge /3 Charge -1/3 Charge Charge Up m-Neutrino nt ne e m t d s b c u nm Quarks Leptons Charge /3 Up Charge -1/3 Down Charge Electron Charge e-Neutrino ne e d u Neutron Proton

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

14 Neutrinos from the Sun Helium Solar radiation: 98 % light
Hans Bethe ( , 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

15 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.”

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

17 First Measurement of Solar Neutrinos
Inverse beta decay of chlorine 600 tons of Perchloroethylene Homestake solar neutrino observatory ( )

18 Elastic scattering or CC reaction
Cherenkov Effect Cherenkov Ring Elastic scattering or CC reaction Light Electron or Muon (Charged Particle) Neutrino Water Georg Raffelt, Max-Planck-Institut für Physik, München Physik Kolloquium, 19. November 2007, RWTH Aachen

19 Super-Kamiokande Neutrino Detector

20 Cherenkov Ring Georg Raffelt, Max-Planck-Institut für Physik, München
Physik Kolloquium, 19. November 2007, RWTH Aachen

21 Super-Kamiokande: Sun in the Light of Neutrinos
Georg Raffelt, Max-Planck-Institut für Physik, München Physik Kolloquium, 19. November 2007, RWTH Aachen

22 SN 1987A Event No.9 in Kamiokande-II
Kamiokande-II detector 2140 tons of water fiducial volume for SN 1987A Hirata et al., PRD 38 (1988) 448

23 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

24 2002 Physics Nobel Prize for Neutrino Astronomy
Ray Davis Jr. ( ) Masatoshi Koshiba (*1926) “for pioneering contributions to astrophysics, in particular for the detection of cosmic neutrinos”

25 SN 1987A Neutrino Story as Told by the Pioneers

26 Supernova Neutrinos 20 Jahre nach SN 1987A
Some Particle-Physics Lessons from SN 1987A Georg Raffelt, Max-Planck-Institut für Physik, München Physik Kolloquium, 19. November 2007, RWTH Aachen

27 The Energy-Loss Argument
Neutrino sphere SN 1987A neutrino signal Neutrino diffusion Late-time signal most sensitive observable 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.) Volume emission of novel particles

28 Astrophysical Axion Bounds
103 106 109 1012 [GeV] fa eV keV meV ma Experiments Tele scope CAST Direct search ADMX Hot dark matter limits (a-p-coupling) Cold Dark Matter Globular clusters (a-g-coupling) Too many events Too much energy loss SN 1987A (a-N-coupling)

29 Neutrino Limits by Intrinsic Signal Dispersion
Time of flight delay by neutrino mass (G. Zatsepin, JETP Lett. 8:205, 1968) For “milli charged” neutrinos, path bent by galactic magnetic field, inducing a time delay mne ≲ 20 eV Loredo & Lamb Ann N.Y. Acad. Sci. 571 (1989) 601 find 23 eV (95% CL limit) from detailed maximum-likelihood analysis Barbiellini & Cocconi, Nature 329 (1987) 21 Bahcall, Neutrino Astrophysics (1989) At the time of SN 1987A competitive with tritium end-point Today mn < 2.2 eV from tritium Cosmological limit today mn ≲ 0.2 eV Assuming charge conservation in neutron decay yields a more restrictive limit of about 310-21 e

30 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 ~ 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 Photons likely obscured for next galactic SN, so this result probably unique to SN 1987A

31 Supernova Neutrinos 20 Jahre nach SN 1987A
Core-Collapse Explosion Mechanism Georg Raffelt, Max-Planck-Institut für Physik, München Physik Kolloquium, 19. November 2007, RWTH Aachen

32 Wilson, Proc. Univ. Illinois Meeting on Num. Astrophys.(1982)
Delayed Explosion Wilson, Proc. Univ. Illinois Meeting on Num. Astrophys.(1982) Bethe & Wilson, ApJ 295 (1985) 14

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

34 Exploding Models (8-10 Solar Masses) with O-Ne-Cores
Kitaura, Janka & Hillebrandt: “Explosions of O-Ne-Mg cores, the Crab supernova, and subluminous type II-P supernovae”, astro-ph/

35 Standing Accretion Shock Instability (SASI)
Mezzacappa et al., Georg Raffelt, Max-Planck-Institut für Physik, München Physik Kolloquium, 19. November 2007, RWTH Aachen

36 Gravitational Waves from Core-Collapse Supernovae
Müller, Rampp, Buras, Janka, & Shoemaker, “Towards gravitational wave signals from realistic core collapse supernova models,” astro-ph/ Asymmetric neutrino emission Bounce Convection The gravitational-wave signal from convection is a generic and dominating feature

37 Supernova Neutrinos 20 Jahre nach SN 1987A
Galactic Supernova Rate Georg Raffelt, Max-Planck-Institut für Physik, München Physik Kolloquium, 19. November 2007, RWTH Aachen

38 Core-Collapse SN Rate in the Milky Way
SN statistics in external galaxies Core-collapse SNe per century 1 2 3 4 5 6 7 8 9 10 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/ 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.

39 Local Group of Galaxies
Events in a detector with 30 x Super-K fiducial volume, e.g. Hyper-Kamiokande 30 60 250

40 Nearby Galaxies with Many Observed Supernovae
M83 (NGC 5236, Southern Pinwheel) D = 4.5 Mpc NGC 6946 D = (5.5 ± 1) Mpc Observed Supernovae: 1923A, 1945B, 1950B, 1957D, 1968L, 1983N Observed Supernovae: 1917A, 1939C, 1948B, 1968D, 1969P, 1980K, 2002hh, 2004et

41 Supernova Neutrinos 20 Jahre nach SN 1987A
Future Supernova Neutrino Observations Georg Raffelt, Max-Planck-Institut für Physik, München Physik Kolloquium, 19. November 2007, RWTH Aachen

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

43 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 ? astro-ph/

44 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]

45 IceCube Neutrino Telescope at the South Pole
1 km3 antarctic ice, instrumented with 4800 photomultipliers 22 of 80 strings installed (2007) Completion until 2011 foreseen

46 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 < 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/ ] Method first discussed by Pryor, Roos & Webster, ApJ 329:355 (1988) Halzen, Jacobsen & Zas astro-ph/

47 LAGUNA - Funded FP7 Design Study
Large Apparati for Grand Unification and Neutrino Astrophysics (see also arXiv: )

48 Supernova Neutrinos 20 Jahre nach SN 1987A
Neutrino Oscillations Georg Raffelt, Max-Planck-Institut für Physik, München Physik Kolloquium, 19. November 2007, RWTH Aachen

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

50 Mixing of Neutrinos with Different Mass
mass m1 mass m2 n Electron neutrino Mass m1 Mass m2 > m1 Mass m1 Mass m2 > m1 Mass m1 Mass m2 > m1 Mass m1 Mass m2 = m1 Mass m1 Mass m2 > m1 Neutrino propagation as a wave phenomenon Georg Raffelt, Max-Planck-Institut für Physik, München Physik Kolloquium, 19. November 2007, RWTH Aachen

51 Neutrino Oscillations
Mass m1 Mass m2 > m1 Oscillation length Georg Raffelt, Max-Planck-Institut für Physik, München Physik Kolloquium, 19. November 2007, RWTH Aachen

52 Neutrino Oscillations
Oscillation length Georg Raffelt, Max-Planck-Institut für Physik, München Physik Kolloquium, 19. November 2007, RWTH Aachen

53 Three-Flavor Neutrino Parameters
Solar 75-92 Atmospheric CHOOZ Solar/KamLAND 2s ranges hep-ph/ Atmospheric/K2K d CP-violating phase m e t 1 Sun Normal 2 3 Atmosphere Inverted Tasks and Open Questions Precision for q12 and q23 How large is q13 ? CP-violating phase d ? Mass ordering ? (normal vs inverted) Absolute masses ? (hierarchical vs degenerate) Dirac or Majorana ?

54 Long-Baseline Experiment K2K
K2K Experiment (KEK to Kamiokande) has confirmed neutrino oscillations, to be followed by T2K (2009)

55 The Future: A Megatonne Detector?
Megatonne detector motivated by Long baseline neutrino oscillations Proton decay Atmospheric neutrinos Solar neutrinos Supernova neutrinos (~105 events for SN at 10 kpc) Similar discussions in US (UNO project) Europe (MEMPHYS project)

56 Neutrino Oscillations in Matter
Lincoln Wolfenstein n f Z W, Z Neutrinos in a medium suffer flavor-dependent refraction (PRD 17:2369, 1978) In Earth or Sun weak potential of order eV “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

57 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/ ] Resonance density for Resonance density for

58 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/

59 Matrices of Density in Flavor Space
Neutrino quantum field Spinors in flavor space Destruction operators for (anti)neutrinos Variables for discussing neutrino flavor oscillations Quantum states (amplitudes) “Matrices of densities” (analogous to occupation numbers) Neutrinos Anti- neutrinos Sufficient for “beam experiments,” but confusing “wave packet debates” for quantifying decoherence effects “Quadratic” quantities, required for dealing with decoherence, collisions, Pauli-blocking, nu-nu-refraction, etc.

60 General Equations of Motion
Vacuum oscillations M is neutrino mass matrix Note opposite sign between neutrinos and antineutrinos Usual matter effect with Nonlinear nu-nu effects are important when nu-nu interaction energy exceeds typical vacuum oscillation frequency (Do not compare with matter effect!)

61 Toy Supernova in “Single-Angle” Approximation
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) Bipolar Oscillations Decline of oscillation amplitude explained in pendulum analogy by inreasing moment of inertia (Hannestad, Raffelt, Sigl & Wong astro-ph/ )

62 Collective SN neutrino oscillations 2006-2007
“Bipolar” collective transformations important, even for dense matter Duan, Fuller & Qian astro-ph/ Numerical simulations Including multi-angle effects Discovery of “spectral splits” Duan, Fuller, Carlson & Qian astro-ph/ , Pendulum in flavor space Collective pair annihilation Pure precession mode Hannestad, Raffelt, Sigl & Wong astro-ph/ Duan, Fuller, Carlson & Qian astro-ph/ Self-maintained coherence vs. self-induced decoherence caused by multi-angle effects Raffelt & Sigl, hep-ph/ Esteban-Pretel, Pastor, Tomas, Raffelt & Sigl, arXiv: Theory of “spectral splits” in terms of adiabatic evolution in rotating frame Raffelt & Smirnov, arXiv: , Duan, Fuller, Carlson & Qian arXiv: , Independent numerical simulations Fogli, Lisi, Marrone & Mirizzi arXiv:

63 Supernova Neutrinos 20 Jahre nach SN 1987A
Cosmic Diffuse Supernova Neutrino Background (DSNB) Georg Raffelt, Max-Planck-Institut für Physik, München Physik Kolloquium, 19. November 2007, RWTH Aachen

64 Diffuse Background Flux of SN Neutrinos
1 SNu = 1 SN / 1010 Lsun,B / 100 years Lsun,B = 0.54 Lsun = 2  1033 erg/s En ~ 3  1053 erg per core-collapse SN 1 SNu ~ 4 Ln / Lg,B Average neutrino luminosity of galaxies ~ photon luminosity Photons come from nuclear energy Neutrinos from gravitational energy For galaxies, average nuclear & gravitational energy release comparable Present-day SN rate of ~ 1 SNu, extrapolated to the entire universe, corresponds to ne flux of ~ 1 cm-2 s-1 Realistic flux is dominated by much larger early star-formation rate  Upper limit ~ 54 cm-2 s-1 [Kaplinghat et al., astro-ph/ ]  “Realistic estimate” ~ 10 cm-2 s-1 [Hartmann & Woosley, Astropart. Phys. 7 (1997) 137] Measurement would tell us about early history of star formation

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

66 Improved Sensitivity with Neutron Tagging
Beacom & Vagins, hep-ph/ [Phys. Rev. Lett., 93 (2004) ] Status of R & D (04/2006) [Mark Vagins, private communication] Detection of DSNB limited by Solar neutrinos for En ≲ 18 MeV Sub-Cherenkov muons from atm nus Solution: neutron tagging from 2.2 MeV gamma from n + p  d invisible in water Cherenkov detector Nov 05: Gd Cl3 added to K2K test tank (kiloton or KT detector) Gd Cl3 is easy to dissolve Gd Cl3 does not significantly affect the light collection Choice of detector materials critical (old rust in KT with Gd Cl3 badly affected transparency) The 20 inch Super-K PMT's operate well in conductive water Gd filtration works as designed at 3.6 tons/h, can easily be scaled up Add gadolinium to Super-Kamiokande Efficient neutron capture on Gd 8 MeV gamma cascade easily visible 0.1% (100 tons of Gd Cl3) achieves > 90% tagging efficiency Diffuse SN nu background (DSNB): a few events per year in Super-K with no background at all Looks promising for Super-K, conceivable within next few years Capital cost negligible for future megatonne-class detectors

67 DSNB Measurement with Neutron Tagging
Beacom & Vagins, hep-ph/ [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

68 The Red Supergiant Betelgeuse (Alpha Orionis)
First resolved image of a star other than Sun Distance (Hipparcos) 130 pc (425 lyr) If Betelgeuse goes Supernova: 6 107 neutrino events in Super-Kamiokande 2.4 103 neutron events per day from Silicon-burning phase (few days warning!), need neutron tagging [Odrzywolek, Misiaszek & Kutschera, astro-ph/ ]

69 Looking forward to the next galactic supernova!
Aachen Skyline Looking forward to the next galactic supernova!