Physics Potential of Future Supernova Neutrino Observations Amol - PowerPoint PPT Presentation

Physics Potential of Future Supernova Neutrino Observations Amol Dighe Tata Institute of Fundamental Research Mumbai, India Neutrino 2008 May 25-31, 2008, Christchurch, New Zealand

Supernova for neutrino physics and astrophysics SN for neutrino oscillation phenomenology Detection of nonzero angle you-know-who Normal vs. inverted mass ordering (both possible even if θ 13 → 0) Neutrino detection for SN astrophysics Pointing to the SN in advance Tracking SN shock wave in neutrinos Diffuse SN neutrino background The flavour of this talk Only standard three-neutrino mixing Only standard SN explosion scenario Concentrate on the exciting developments in the last two years: “neutrino refraction / collective effects”

Supernova for neutrino physics and astrophysics SN for neutrino oscillation phenomenology Detection of nonzero angle you-know-who Normal vs. inverted mass ordering (both possible even if θ 13 → 0) Neutrino detection for SN astrophysics Pointing to the SN in advance Tracking SN shock wave in neutrinos Diffuse SN neutrino background The flavour of this talk Only standard three-neutrino mixing Only standard SN explosion scenario Concentrate on the exciting developments in the last two years: “neutrino refraction / collective effects”

Outline Neutrino production and detection 1 Neutrino emission and primary spectra Detection of a galactic supernova Neutrino propagation and flavor conversions 2 Matter effects inside the star: collective and MSW Earth matter effects Shock wave effects Smoking gun signals 3 During neutronization burst During the accretion and cooling phase Concluding remarks 4

Outline Neutrino production and detection 1 Neutrino emission and primary spectra Detection of a galactic supernova Neutrino propagation and flavor conversions 2 Matter effects inside the star: collective and MSW Earth matter effects Shock wave effects Smoking gun signals 3 During neutronization burst During the accretion and cooling phase Concluding remarks 4

Outline Neutrino production and detection 1 Neutrino emission and primary spectra Detection of a galactic supernova Neutrino propagation and flavor conversions 2 Matter effects inside the star: collective and MSW Earth matter effects Shock wave effects Smoking gun signals 3 During neutronization burst During the accretion and cooling phase Concluding remarks 4

Outline Neutrino production and detection 1 Neutrino emission and primary spectra Detection of a galactic supernova Neutrino propagation and flavor conversions 2 Matter effects inside the star: collective and MSW Earth matter effects Shock wave effects Smoking gun signals 3 During neutronization burst During the accretion and cooling phase Concluding remarks 4

Outline Neutrino production and detection 1 Neutrino emission and primary spectra Detection of a galactic supernova Neutrino propagation and flavor conversions 2 Matter effects inside the star: collective and MSW Earth matter effects Shock wave effects Smoking gun signals 3 During neutronization burst During the accretion and cooling phase Concluding remarks 4

Outline Neutrino production and detection 1 Neutrino emission and primary spectra Detection of a galactic supernova Neutrino propagation and flavor conversions 2 Matter effects inside the star: collective and MSW Earth matter effects Shock wave effects Smoking gun signals 3 During neutronization burst During the accretion and cooling phase Concluding remarks 4

Neutrino emission Gravitational core collapse ⇒ Shock Wave Neutronization burst: ν e emitted for ∼ 10 ms Cooling through neutrino emission: ν e , ¯ ν e , ν µ , ¯ ν µ , ν τ , ¯ ν τ Duration: About 10 sec Emission of 99% of the SN energy in neutrinos ¿¿¿ Explosion ???

Neutrino emission Gravitational core collapse ⇒ Shock Wave Neutronization burst: ν e emitted for ∼ 10 ms Cooling through neutrino emission: ν e , ¯ ν e , ν µ , ¯ ν µ , ν τ , ¯ ν τ Duration: About 10 sec Emission of 99% of the SN energy in neutrinos ¿¿¿ Explosion ???

Neutrino emission Gravitational core collapse ⇒ Shock Wave Neutronization burst: ν e emitted for ∼ 10 ms Cooling through neutrino emission: ν e , ¯ ν e , ν µ , ¯ ν µ , ν τ , ¯ ν τ Duration: About 10 sec Emission of 99% of the SN energy in neutrinos ¿¿¿ Explosion ???

Neutrino emission Gravitational core collapse ⇒ Shock Wave Neutronization burst: ν e emitted for ∼ 10 ms Cooling through neutrino emission: ν e , ¯ ν e , ν µ , ¯ ν µ , ν τ , ¯ ν τ Duration: About 10 sec Emission of 99% of the SN energy in neutrinos ¿¿¿ Explosion ???

Primary fl uxes and spectra Neutrino fluxes: � − ( α + 1 ) E � ν i = N i E α exp F 0 E 0 E 0 , α : in general time dependent Energy hierarchy: E 0 ( ν e ) < E 0 (¯ ν e ) < E 0 ( ν x ) 0.07 E 0 ( ν e ) ≈ 10–12 MeV 0.06 E 0 (¯ ν e ) ≈ 13–16 MeV 0.05 0.04 E 0 ( ν x ) ≈ 15–25 MeV 0.03 α ν i ≈ 2–4 0.02 0.01 E(MeV) 10 20 30 40

Flavor-dependence of neutrino fl uxes 25 25 20 20 〈 E 〉 15 15 10 10 solid line: ¯ ν e 0 1 2 3 4 0 250 500 750 6 − 6 ν dotted line: ¯ ν x L [10 52 erg s -1 ] e − 5 5 ν x 4 4 3 3 2 2 1 1 0 0 0 1 2 3 4 0 250 500 750 Time [s] Time [ms] Φ 0 ( ν e ) Φ 0 (¯ ν e ) Model � E 0 ( ν e ) � � E 0 (¯ ν e ) � � E 0 ( ν x ) � Φ 0 ( ν x ) Φ 0 ( ν x ) Garching (G) 12 15 18 0.8 0.8 Livermore (L) 12 15 24 2.0 1.6 G. G. Raffelt, M. T. Keil, R. Buras, H. T. Janka and M. Rampp, astro-ph/0303226 T. Totani, K. Sato, H. E. Dalhed and J. R. Wilson, Astrophys. J. 496, 216 (1998)

Outline Neutrino production and detection 1 Neutrino emission and primary spectra Detection of a galactic supernova Neutrino propagation and flavor conversions 2 Matter effects inside the star: collective and MSW Earth matter effects Shock wave effects Smoking gun signals 3 During neutronization burst During the accretion and cooling phase Concluding remarks 4

SN1987A Confirmed the SN cooling mechanism through neutrinos Number of events too small to say anything concrete about neutrino mixing Some constraints on SN parameters obtained (Hubble image)

Signal expected from a galactic SN (10 kpc) Water Cherenkov detector: ν e p → ne + : ≈ 7000 – 12000 ∗ ¯ ν e − → ν e − : ≈ 200 – 300 ∗ ν e + 16 O → X + e − : ≈ 150–800 ∗ ∗ Events expected at Super-Kamiokande with a galactic SN at 10 kpc Carbon-based scintillation detector: ν e p → ne + ¯ ν + 12 C → ν + X + γ (15.11 MeV) Liquid Argon detector: ν e + 40 Ar → 40 K ∗ + e −

Pointing to the SN in advance Neutrinos reach 6-24 hours before the light from SN explosion (SNEWS network) ν e p → ne + : nearly isotropic background ¯ ν e − → ν e − : forward-peaked “signal” Background-to-signal ratio: N B / N S ≈ 30–50 SN at 10 kpc may be detected within a cone of ∼ 5 ◦ at SK J. Beacom and P . Vogel, PRD 60, 033007 (1999) Neutron tagging with Gd im- proves the pointing accuracy 2–3 times R.Tomàs et al. , PRD 68, 093013 (2003). GADZOOKS J.Beacom and M.Vagins, PRL 93, 171101 (2004)

Diffuse SN neutrino background 10 SRN 1 0.1 10 1 0.1 0 20 40 60 80 100 0 10 20 30 40 50 Within reach of HK, easier if Gd added “Invisible muon” background needs to be taken care of S. Ando and K. Sato, New J. Phys. 6, 170 (2004) S.Chakraborti, B.Dasgupta, S.Choubey, K.Kar, arXiv:0805.xxxx

Outline Neutrino production and detection 1 Neutrino emission and primary spectra Detection of a galactic supernova Neutrino propagation and flavor conversions 2 Matter effects inside the star: collective and MSW Earth matter effects Shock wave effects Smoking gun signals 3 During neutronization burst During the accretion and cooling phase Concluding remarks 4

Propagation through matter of varying density SUPERNOVA EARTH VACUUM envelope ν core 14 10 ρ=10 g/cc 12 10 0.1 10 km 10 R kpc 10000 km sun Inside the SN: flavour conversion Collective effects and MSW matter effects Between the SN and Earth: no flavour conversion Mass eigenstates travel independently Inside the Earth: flavour conversion MSW matter effects ( if detector is on the other side )

Outline Neutrino production and detection 1 Neutrino emission and primary spectra Detection of a galactic supernova Neutrino propagation and flavor conversions 2 Matter effects inside the star: collective and MSW Earth matter effects Shock wave effects Smoking gun signals 3 During neutronization burst During the accretion and cooling phase Concluding remarks 4

Nonlinear effects due to ν − ν coherent interactions Large neutrino density ⇒ substantial ν – ν potential H = H vac + H MSW + H νν M 2 / ( 2 p ) H vac ( � p ) = √ H MSW = 2 G F n e − diag ( 1 , 0 , 0 ) √ d 3 q � H νν ( � � ρ ( � ρ ( � � p ) = 2 G F ( 2 π ) 3 ( 1 − cos θ pq ) q ) − ¯ q ) Coherent scattering and nonlinear effects General formalism: J. Pantaleone, M.Thomson, B.McKellar, V.A.Kostelecky, S. Samuel, G.Sigl, G.G.Raffelt, et al. , (1992-1998) Numerical simulations in SN context: H. Duan, G. Fuller, J. Carlson, Y. Qian, et al. (2006-2008)