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LAUNCH 09. Heidelberg , 9-12 November 2009. Physics and astrophysics of SN neutrinos : What could we learn ?. Alessandro MIRIZZI (Hamburg Universität). OUTLINE. New interpretations of SN 1987A n ’ s. Physics potential of current and future SN n detectors.
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LAUNCH 09 Heidelberg, 9-12 November 2009 Physics and astrophysicsof SN neutrinos: Whatcouldwelearn ? Alessandro MIRIZZI (Hamburg Universität)
OUTLINE New interpretationsof SN 1987A n’s Physics potential of current and future SN n detectors SNn collective oscillations and possible signatures Conclusions Alessandro Mirizzi LAUNCH 09 Heidelberg, 12 November 2009
Core collapse SN corresponds to the terminal phase of a massive star [M ≳8 M] which becomes instable at the end of its life. It collapses and ejects its outer mantle in a shock wave drivenexplosion. n n n n n n n n SUPERNOVA NEUTRINOS • ENERGY SCALES:99% of the released energy (~ 1053 erg) is emitted by n and n of all flavors, with typical energies E ~ O(15 MeV). • TIME SCALES:Neutrino emission lasts ~10 s • EXPECTED:1-3 SN/century in our galaxy (d O(10) kpc). Alessandro Mirizzi LAUNCH 09 Heidelberg, 12 November 2009
NEUTRONIZATION ACCRETION • NEUTRONIZATION BURST:ne COOLING • Duration: ~ 25 ms after the explosion • Emitted energy : E~ 1051 erg • (1/100 of total energy) • THERMAL BURST (ACCRETION + COOLING):ne , ne , nx , nx • Accretion: ~0.5 s • Cooling: ~10 s • Emitted energy: E~ 1053 erg SN NEUTRINO FLUXES Results of neutrino emission based on the numerical simulations of SN explosion. [see, e.g., T. Totani, K.Sato, H.E. Dalhed, and J.R. Wilson, Astrophys. J. 496, 216 (1998)]. Alessandro Mirizzi LAUNCH 09 Heidelberg, 12 November 2009
Sanduleak -69 202 Supernova 1987A23 February 1987 Tarantula Nebula Large Magellanic Cloud Distance 50 kpc (160.000 light years)
SN1987A Neutrino Burst Observation : First verification of stellar evolution mechanism Alessandro Mirizzi LAUNCH 09 Heidelberg, 12 November 2009
Energy Distribution of SN 1987A Neutrinos Kamiokande-II (Japan) Water Cherenkov detector 2140 tons Irvine-Michigan-Brookhaven (US) Water Cherenkov detector 6800 tons Alessandro Mirizzi LAUNCH 09 Heidelberg, 12 November 2009
Total binding energy Theory Average ne energy Interpreting SN1987A neutrinos [B. Jegerlehner, F. Neubig and G. Raffelt, PRD 54, 1194 (1996); A.M., and G. Raffelt, PRD 72, 063001 (2005)] • Imposing thermal n spectra, tension between the two experiments (marginal overlap between the two separate CL) • Tension between the experiments and the theory. But…. Alessandro Mirizzi LAUNCH 09 Heidelberg, 12 November 2009
NEW LONG-TERM COOLING CALCULATION Lower n average energies…In agreement with SN 1987A data Fischer et al. (Basel group), arXiv: 0908.1871
SN NEUTRINO SPECTRUM FROM SN1987A [Yuksel & Beacom, astro-ph/0702613] Original SN n energy spectra expected to be quasi-thermal SN1987A inferred n energy spectrum shows strong deviations from quasi-thermal distribution: ? Possible effects of: • neutrino mixing • n-n interactions • n decay • nonstandard n interactions • additional channels of energy exchange among flavors Possible to reconcile detection and theory… Still many open questions! Alessandro Mirizzi LAUNCH 09 Heidelberg, 12 November 2009
What could we see “tomorrow”? SN 20XXA !
LVD (400) Borexino (80) Large Detectors for Supernova Neutrinos Super-Kamiokande (104) KamLAND (330) MiniBooNE (200) In brackets events for a “fiducial SN” at distance 10 kpc IceCube (106)
SEARCH FOR SN NEUTRINO BURSTS SUPER-KAMIOKANDE MINIBOONE Upper limit: 0.69 SN year-1 @ 90 % C.L. for d < 13.5 kpc Upper limit: 0.32 SN year-1 @ 90 % C.L. for d < 100 kpc [Miniboone collaboration, arXiv: 0910.3182] [SK collaboration, arXiv: 0706.2283] Alessandro Mirizzi LAUNCH 09 Heidelberg, 12 November 2009
Accretion phase Cooling phase Simulated Supernova Signal at Super-Kamiokande Simulation for Super-Kamiokande SN signal at 10 kpc, based on a numerical Livermore model [Totani, Sato, Dalhed & Wilson, ApJ 496 (1998) 216]
Simulated Supernova Signal at Ice-Cube [Dighe, Keil and Raffelt, hep-ph/0303210] LIVERMORE GARCHING Possibletoreconstruct the SN nlightcurvewithcurrentdetectors. Discriminationbtwdifferentsimulations.
Millisecond bounce time reconstruction SUPER-KAMIOKANDE ICE-CUBE • Emission model adapted to • measured SN 1987A data • “Pessimistic distance” of 20 kpc • Determine bounce time to within • a few tens of milliseconds Onset of neutrino emission [Halzen & Raffelt, arXiv:0908.2317] [Pagliaroli, Vissani, Coccia & Fulgione arXiv:0903.1191] External trigger for gravitational-wave search Alessandro Mirizzi LAUNCH 09 Heidelberg, 12 November 2009
SIGNALS OF QCD PHASE TRANSITION IN SN n [Sagert et al., arXiv:0809.4225] If QCD phase transition happens in a SN → second peak in the neutrino signal. In contrast to the first neutronization burst, second neutrino burst dominated by the emission of anti-neutrinos
PROBING QCD PHASE TRANSITION IN SN n DETECTORS [Dasgupta, Fischer, Horiuchi, Liebendoerfer, A.M., in preparation] ICE-CUBE SUPER-KAMIOKANDE While the standard neneutronizationburstisdifficulttodetectwithcurrentdetectors, the QCD-inducednepeakwouldbesuccessfullytrackedby IBD reactions. Alessandro Mirizzi LAUNCH 09 Heidelberg, 12 November 2009
LENA LAr TPC Scintillator UNO, MEMPHYS, HYPER-K GLACIER Next generation Detectors for Supernova Neutrinos Next-generation large volume detectors might open a new era in SN neutrino detection: • 0.4 Mton WATER Cherenkov detectors • 100 kton Liquid Ar TPC • 50 kton scintillator Mton Cherenkov See LAGUNA Collaboration, “Large underground, liquid based detectors for astro-particle physics in Europe: Scientific case and prospects,” arXiV:0705.0116 [hep-ph]
Golden channel: Inverse beta decay (IBD) of ne 0.4 Mton Water Cherenkov detector [ Fogli, Lisi, A.M., Montanino, hep-ph/0412046] ~2.5×105 events @ 10 kpc Alessandro Mirizzi LAUNCH 09 Heidelberg, 12 November 2009
SN n FROM NEARBY GALAXIES [Ando, Beacom, Yuksel, astro-ph/0503321] The core-collpase SN rate in 10 Mpcis ̴ 1/ year. Detection of ̴ 1 n per year in 1 Mton WC detector @ 1 Mton WC Alessandro Mirizzi LAUNCH 09 Heidelberg, 12 November 2009
SN n FLAVOR TRANSITIONS The flavor evolution in matter is described by the non-linear MSW equations: In the standard 3n framework Kinematical mass-mixing term Dynamical MSW term (in matter) Neutrino-neutrino interactions term (non-linear) Alessandro Mirizzi LAUNCH 09 Heidelberg, 12 November 2009
M2 = - , + , ± Dm2 “solar” “atmospheric” n3 • Dm2 inverted hierarchy n1 • dm2/2 n1 • dm2/2 n2 n2 -dm2/2 -dm2/2 dm2 dm2 2 2 n3 -Dm2 normal hierarchy VACUUM OSCILLATIONS: 3n FRAMEWORK Mixing parameters:U = U (q12, q13, q23) as for CKM matrix Mass-gap parameters: (see,e.g., Fogli et al., 0805.2517) Alessandro Mirizzi LAUNCH 09 Heidelberg, 12 November 2009
SN SELF-INTERACTION POTENTIAL AND MATTER POTENTIAL r < 200 km : Self-induced collective oscillations r > 200 km : Ordinary MSW effects Recent review: A. Dighe: arXiv:0809.2977 [hep-ph]
LARGE NEUTRINO DENSITY t SYNCHRONIZED OSCILLATIONS BY NEUTRINO-NEUTRINO INTERACTIONS Example: evolution of neutrino momenta with a thermal distribution If neutrino density dominates, synchronoized oscillations with a characteristic common oscillation frequency [Pastor, Raffelt, Semikoz, hep-ph/0109033]
Equal densities of n and n INVERTED HIERARCHY + small θ LARGE flavour transformations: Periodic if density constant • Non-periodic if ndensity decreases (SUPERNOVA!) • Excess of ne over ne • Occurs for very small mixing angles • Almost independent of the presence of dense normal matter PENDULAR OSCILLATIONS [Hannestad, Raffelt, Sigl, Wong, astro-ph/0608695] Complete flavor conversions! Alessandro Mirizzi LAUNCH 09 Heidelberg, 12 November 2009
Onset radius of collective conversions log10q13 COLLECTIVE OSCILLATIONS IN IH @ q13→ 0 Collective flavor conversions in inverted hierarchy are expected also for q13→0, when further MSW matter effects are negligible [Duan, Fuller, Carlson & Qian, arXiv:0707.0290 (astro-ph)] Effect logarithmically delayed when q13→0 Alessandro Mirizzi LAUNCH 09 Heidelberg, 12 November 2009
NEUTRINO FLUX NUMBERS [Raffelt et al. (Garching group), astro-ph/0303226] ne ne nx Accretion phase Cooling phase Excessofne due todeleponization Moderate flavorhierarchy, possibleexcessofnx
SPECTRAL SPLITS IN THE ACCRETION PHASE [G.L.Fogli, E.Lisi, A. Marrone, A.M. , arXiV: 0707.1998 [hep-ph]] Initial fluxes at neutrinosphere (r ~10 km) (ratio typical of accretion phase) Inverted mass hierarchy Fluxes at the end of collective effects (r ~200 km) Nothing happens in NH
MULTIPLE SPECTRAL SPLITS IN THE COOLING PHASE [Dasgupta, Dighe, Raffelt & Smirnov, arXiv:0904.3542 [hep-ph] ] e x (typical in cooling phase) Splits possible in both normal and inverted hierarchy, for n & n !! Possible time-dependent signatures in the SNnsignal Alessandro Mirizzi LAUNCH 09 Heidelberg, 12 November 2009
TERNARY LUMINOSITY DIAGRAM [Fogli, Lisi, Marrone, Tamborra, arXiv:0907.5115] Equipartition of luminosities Movingfrom the equiparitionpoint, doublesplits can occurforbothn and n Phenomenology crucially dependent on the original neutrino fluxes Alessandro Mirizzi LAUNCH 09 Heidelberg, 12 November 2009
COMPARING TWO SN SIMULATIONS [BASEL 0908.1871] [GARCHING astro-ph/0303226] ACCRETION PHASE . Single split in n and complete swap forn in IH. No effect in NH. Fluxorderingrobustconsequenceof the coredeleptonization COOLING PHASE BASEL (equipartition of luminosities) as in the accretion. GARCHING (deviationfromequipartion) Multiple splits in NH & IH forbothn and n
SN n OSCILLATED SPECTRA [Table by Amol Dighe] Alessandro Mirizzi LAUNCH 09 Heidelberg, 12 November 2009
ne + p → n + e+ USING EARTH EFFECT TO DIAGNOSE COLLECTIVE OSCILLATIONS Earth matter crossing induces additional n conversions between n1 and n2 mass eigenstates. The main signature of Earth matter effects – oscillatory modulations of the observed energy spectra – is unambiguous since it can not be mimicked by known astrophysical phenomena Alessandro Mirizzi LAUNCH 09 Heidelberg, 12 November 2009
MASS HIERARCHY DETERMINATION AT EXTREMELY SMALL q13 [Dasgupta, Dighe, A.M., arXiv:0802.1481 [hep-ph]] (Accretion phase) Ratio of spectra in two water Cherenkov detectors (0.4 Mton), one shadowed by the Earth, the other not. Alessandro Mirizzi LAUNCH 09 Heidelberg, 12 November 2009
CONCLUSIONS Observing SN neutrinos is the next frontier of low-energy neutrino astronomy The physics potential of current and next-generation detectors in this context is enormous, both for particle physics and astrophysics. SN provideveryextremeconditions, where neutrino-neutrino interactions prove tobesurprisinglyimportant Lot of theoretical work still needed to understand neutrino flavor conversions during a stellar collapse Difficulttomakerobustpredictions at the moment: Necessary more reliablepredictionsofprimaryfluxes. Next SN nburstwill “calibrate” the simulations. SUCCESS IS GUARANTEED !! Alessandro Mirizzi LAUNCH 09 Heidelberg, 12 November 2009