Heidelberg, 9-12 November 2009 LAUNCH 09 Physics and astrophysics of SN neutrinos: What could we...
-
Upload
pearl-walker -
Category
Documents
-
view
217 -
download
0
Transcript of Heidelberg, 9-12 November 2009 LAUNCH 09 Physics and astrophysics of SN neutrinos: What could we...
Heidelberg, 9-12 November 2009Heidelberg, 9-12 November 2009
LAUNCH 09
Physics and astrophysics of SN Physics and astrophysics of SN neutrinos: neutrinos:
What could we learn ?What could we learn ?
Alessandro MIRIZZI
(Hamburg Universität)
OUTLINE
New interpretations of SN 1987A ’s
Physics potential of current and future SN detectors
SN 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 driven explosion.
SUPERNOVA NEUTRINOS
TIME SCALES: Neutrino emission lasts ~10 s
EXPECTED: 1-3 SN/century in
our galaxy (d O (10) kpc).
ENERGY SCALES: 99% of the released energy (~ 1053 erg) is emitted by and of all flavors, with typical energies E ~ O(15 MeV).
Alessandro Mirizzi LAUNCH 09 Heidelberg, 12 November 2009
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)].
NEUTRONIZATION BURST:e
• Duration: ~ 25 ms after the explosion
• Emitted energy : E~ 1051 erg
(1/100 of total energy)
• Accretion: ~ 0.5 s
• Cooling: ~ 10 s
• Emitted energy: E~ 1053 erg
THERMAL BURST (ACCRETION + COOLING): e , e , x , x
AC
CR
ET
ION
CO
OL
ING
NEUTRONIZATION
SN NEUTRINO FLUXES
Alessandro Mirizzi LAUNCH 09 Heidelberg, 12 November 2009
Sanduleak Sanduleak 69 69 202202
Large Magellanic Cloud Large Magellanic Cloud Distance 50 kpcDistance 50 kpc (160.000 light years)(160.000 light years)
Tarantula NebulaTarantula Nebula
Supernova 1987ASupernova 1987A 23 February 198723 February 1987
SN1987A Neutrino Burst Observation : SN1987A Neutrino Burst Observation : First verification of stellar evolution mechanismFirst verification of stellar evolution mechanism
Alessandro Mirizzi LAUNCH 09 Heidelberg, 12 November 2009
Energy Distribution of SN 1987A Neutrinos
Kamiokande-II (Japan)Water Cherenkov detector2140 tons
Irvine-Michigan-Brookhaven (US)Water Cherenkov detector6800 tons
Alessandro Mirizzi LAUNCH 09 Heidelberg, 12 November 2009
[B. Jegerlehner, F. Neubig and G. Raffelt, PRD 54, 1194 (1996); A.M., and G. Raffelt, PRD 72, 063001 (2005)]
• Imposing thermal spectra, tension between the two experiments (marginal overlap between the two separate CL)
• Tension between the experiments and the theory.
To
tal
bin
din
g e
ner
gy
Average e energy
Theory
Interpreting SN1987A neutrinos
But….
Alessandro Mirizzi LAUNCH 09 Heidelberg, 12 November 2009
NEW LONG-TERM COOLING CALCULATIONLower average energies…In agreement with SN 1987A data
Fischer et al. (Basel group), arXiv: 0908.1871
Possible to reconcile detection and theory… Still many open questions!
SN NEUTRINO SPECTRUM FROM SN1987A[Yuksel & Beacom, astro-ph/0702613]
Original SN energy spectra expected to be quasi-thermal
SN1987A inferred energy spectrum shows strong deviations from quasi-thermal distribution:
Possible effects of:
• neutrino mixing
• interactions
• decay
• nonstandard interactions
• additional channels of energy exchange among flavors
?Alessandro Mirizzi LAUNCH 09 Heidelberg, 12 November 2009
What could we see “tomorrow”?
What could we see “tomorrow”?
SN 20XXA !SN 20XXA !
Large Detectors for Supernova Neutrinos
Super-Kamiokande (10Super-Kamiokande (1044))KamLAND (330)KamLAND (330)
MiniBooNE (200)MiniBooNE (200)
In brackets eventsIn brackets eventsfor a “fiducial SN”for a “fiducial SN”at distance 10 kpcat distance 10 kpc
LVD (400)LVD (400)Borexino (80)Borexino (80)
IceCube (10IceCube (1066))
SEARCH FOR SN NEUTRINO BURSTS
SUPER-KAMIOKANDE MINIBOONE
Upper limit: 0.32 SN year-1 @ 90 % C.L.for d < 100 kpc[SK collaboration, arXiv: 0706.2283]
Upper limit: 0.69 SN year-1 @ 90 % C.L.for d < 13.5 kpc
[Miniboone collaboration, arXiv: 0910.3182]
Alessandro Mirizzi LAUNCH 09 Heidelberg, 12 November 2009
Accretion phase
Cooling phase
Simulation for Super-Kamiokande SN signal at 10 kpc,Simulation for Super-Kamiokande SN signal at 10 kpc,based on a numerical Livermore modelbased on a numerical Livermore model[Totani, Sato, Dalhed & Wilson, ApJ 496 (1998) 216][Totani, Sato, Dalhed & Wilson, ApJ 496 (1998) 216]
Simulated Supernova Signal at Super-Kamiokande
Simulated Supernova Signal at Ice-Cube[Dighe, Keil and Raffelt, hep-ph/0303210]
LIVERMORE GARCHING
Possible to reconstruct the SN lightcurve with current detectors. Discrimination btw different simulations.
Millisecond bounce time reconstruction
Onset of neutrinoOnset of neutrinoemissionemission
• Emission model adapted toEmission model adapted to measured SN 1987A datameasured SN 1987A data
• “ “Pessimistic distance” of 20 kpcPessimistic distance” of 20 kpc
• Determine bounce time to withinDetermine bounce time to within a few tens of millisecondsa few tens of milliseconds
SUPER-KAMIOKANDE ICE-CUBE
[Pagliaroli, Vissani, Coccia & Fulgione arXiv:0903.1191]
[Halzen & Raffelt, arXiv:0908.2317]
External trigger for gravitational-wave search
Alessandro Mirizzi LAUNCH 09 Heidelberg, 12 November 2009
SIGNALS OF QCD PHASE TRANSITION IN SN [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 DETECTORS
[Dasgupta, Fischer, Horiuchi, Liebendoerfer, A.M., in preparation]
While the standard e neutronization burst is difficult to detect with current detectors, the QCD-induced e peak would be successfully tracked by IBD reactions.
SUPER-KAMIOKANDEICE-CUBE
Alessandro Mirizzi LAUNCH 09 Heidelberg, 12 November 2009
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
UNO, MEMPHYS, HYPER-K
Mton Cherenkov
LENA
Scintillator
See LAGUNA Collaboration, “Large underground, liquid based detectors for astro-particle physics in Europe: Scientific case and prospects,” arXiV:0705.0116 [hep-ph]
Next generation Detectors for Supernova Neutrinos
GLACIER
LAr TPC
0.4 Mton Water Cherenkov detector
Golden channel: Inverse beta decay (IBD) of e
~2.5×105 events @ 10 kpc
[ Fogli, Lisi, A.M., Montanino, hep-ph/0412046]
Alessandro Mirizzi LAUNCH 09 Heidelberg, 12 November 2009
SN FROM NEARBY GALAXIES
The core-collpase SN rate in 10 Mpc is R 1/ year. Detection of R 1 per year in 1 Mton WC detector
@ 1 Mton WC
[Ando, Beacom, Yuksel, astro-ph/0503321]
Alessandro Mirizzi LAUNCH 09 Heidelberg, 12 November 2009
COLLECTIVE SUPERNOVA COLLECTIVE SUPERNOVA NEUTRINO OSCILLATIONSNEUTRINO OSCILLATIONS
SN FLAVOR TRANSITIONS
The flavor evolution in matter is described by the non-linear MSW equations:
In the standard 3 framework
Kinematical mass-mixing term
Dynamical MSW term (in matter)
vac e
di H H Hdx
2 (1 cos ) F pq q qH G dq
2 †
2vac
U M UH
E
2 diag( ,0,0)e F eH G N
Neutrino-neutrino interactions term (non-linear)
Alessandro Mirizzi LAUNCH 09 Heidelberg, 12 November 2009
Mixing parameters: U = U (12, 13, 23) as for CKM matrix
Mass-gap parameters:M2 = - , + , ±
m2m2
2m2
2
“solar” “atmospheric”
normal hierarchy
inverted hierarchy
m2/2-m2/2
m2
m2
m2/2-m2/2
1 12 2
3
3
VACUUM OSCILLATIONS: 3 FRAMEWORK
(see,e.g., Fogli et al., 0805.2517)
2 3 2
2 5 2
12
23
13
2.4 10 eV
8. 10 eV
0.6
/ 4
0.1
m
m
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]
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]
LARGE NEUTRINO DENSITY
PENDULAR OSCILLATIONS
[Hannestad, Raffelt, Sigl, Wong, astro-ph/0608695]
Equal densities of and INVERTED HIERARCHY + small θLARGE flavour transformations:
Periodic if density constant
Non-periodic if density decreases (SUPERNOVA!)
Excess of e over e
• Occurs for very small mixing angles• Almost independent of the presence of
dense normal matter
Complete flavor conversions!
Alessandro Mirizzi LAUNCH 09 Heidelberg, 12 November 2009
Ons
et r
adiu
s of
col
lect
ive
conv
ersi
ons
log10 13
Collective flavor conversions in inverted hierarchy are expected also for 13→0, when further MSW matter effects are negligible
[Duan, Fuller, Carlson & Qian, arXiv:0707.0290 (astro-ph)]
Effect logarithmically delayed when 13→0
COLLECTIVE OSCILLATIONS IN IH @ 13→ 0
Alessandro Mirizzi LAUNCH 09 Heidelberg, 12 November 2009
Accretion phase Cooling phase
xee FFF
xee FFF
eex FFF
eex FFF
NEUTRINO FLUX NUMBERS
Excess of e due to deleponization
Moderate flavor hierarchy, possible excess of x
[Raffelt et al. (Garching group), astro-ph/0303226]
e
e
x
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)
Fluxes at the end of collective effects (r ~200 km)Nothing happens in NH
Inve
rted
mas
s h
iera
rch
y
: : 2.4 :1.6 :1.0e e xF F F
(ratio typical of accretion phase)
MULTIPLE SPECTRAL SPLITS IN THE COOLING PHASE[Dasgupta, Dighe, Raffelt & Smirnov, arXiv:0904.3542 [hep-ph] ]
: : 0.85 : 0.75 :1.00e e xF F F
e (typical in cooling phase)
Splits possible in both normal and inverted hierarchy, for &
Possible time-dependent signatures in the SN signal
Alessandro Mirizzi LAUNCH 09 Heidelberg, 12 November 2009
x
TERNARY LUMINOSITY DIAGRAM[Fogli, Lisi, Marrone, Tamborra, arXiv:0907.5115]
Equipartition of luminosities
)6/4,6/1,6/1()4,,( xee LLL
Moving from the equiparition point, double splits can occur for both and
Phenomenology crucially dependent on the original neutrino fluxes
Alessandro Mirizzi LAUNCH 09 Heidelberg, 12 November 2009
[GARCHING astro-ph/0303226] [BASEL 0908.1871]
COMPARING TWO SN SIMULATIONS
COOLING PHASE BASEL (equipartition of luminosities)
xee FFF ACCRETION PHASE . Single split in and complete swap for in IH. No effect in NH. Flux ordering robust consequence of the core deleptonization
xee FFF as in the accretion. GARCHING (deviation from equipartion) eex FFF Multiple splits in NH & IH for both and
[Table by Amol Dighe]
SN OSCILLATED SPECTRA
00
00
)1(
)1(
xee
xee
FpFpF
FpFpF
Alessandro Mirizzi LAUNCH 09 Heidelberg, 12 November 2009
USING EARTH EFFECT TO DIAGNOSE COLLECTIVE OSCILLATIONS
Earth matter crossing induces additional conversions between 1 and 2 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
e + p → n + e+
Alessandro Mirizzi LAUNCH 09 Heidelberg, 12 November 2009
MASS HIERARCHY DETERMINATION AT EXTREMELY SMALL
[Dasgupta, Dighe, A.M., arXiv:0802.1481 [hep-ph]]
Ratio of spectra in two water Cherenkov detectors (0.4 Mton), one shadowed by the Earth, the other not.
shadowed unshadowede e
unshadowede
F FR
F
(Accretion phase)
Alessandro Mirizzi LAUNCH 09 Heidelberg, 12 November 2009
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.
CONCLUSIONS
Alessandro Mirizzi LAUNCH 09 Heidelberg, 12 November 2009
SN provide very extreme conditions, where neutrino-neutrino interactions prove to be surprisingly important
Lot of theoretical work still needed to understand neutrino flavor conversions during a stellar collapse
Difficult to make robust predictions at the moment: Necessary more reliable predictions of primary fluxes. Next SN burst will “calibrate” the simulations.
SUCCESS IS GUARANTEED !!