1. (Institut de Physique Nucléaire Orsay, France)ne nt nm NS
Neutrinos and
Supernovae n
Cristina VOLPE
(Institut de Physique Nucléaire Orsay, France)

2. OUTLINE Progress in understanding neutrino flavour conversion
in explosive media
Observations : learning
about supernova dynamics
and neutrino properties
OUTLINE
Low energy n-nucleus cross sections
and future facilities

3. After the SN1987A… future observations crucial
Core-collapse supernova (SN) simulations
Bruenn et al,
SN simulations have reached a high
degree of complexity : 2D-3D,
convection, realistic neutrino
transport and nuclear networks.
Marek & Janka,ApJL694(2009)664. NS ne nt nm
Hüdepohl et al.PRL 104, (2010)
Neutrinos follow closely the explosion.
The supernova explosion
mechanism delineated :
due to a combination of
convection- neutrino – hydro
instability (SASI).
After the SN1987A… future observations crucial
SN EXPLOSION CLOSE ?

4. Neutrino flavour conversion
in SN
The Mikheev-Smirnov-Wolfenstein effect :
the beautiful explanation of the « solar
neutrino deficit » problem .
V(r) GF re. ne e W
The case of core-collapse supernovae turns
out to be much more complex : new flavour
conversion phenomena emerge.
Turbulence
shock waves nn
interaction
Collective flavour
conversion effects
Multiple
MSW
resonances
New features
arise
Understanding the different facets
of flavour conversion in SN :
the object of intense investigation.

5. nn interaction shock waves Turbulence
J. Pantaleone, PLB 287 (1992), Samuel,PRD 48 (1993), Sigl and Raffelt NPB 406 (1993),
Pastor, Raffelt, Semikoz, PRD 65 (2002), Qian and Fuller, PRD 52 (1995) , Balantekin and
Yuksel, New. J. Phys. 7 (2005), Duan,Fuller,Qian PRD74 (2006), PRL 97 (2006), PRD 75,
76 (2007), PRL 2008, PRD77 (2008), Fogli, Lisi, Mirizzi, Marrone, JCAP 2007,
Raffelt and Smirnov, PRD 76 (2007), Estebal et al PRD 76 (2007), Gava and Volpe
PRD(2008), Kneller, Gava, Volpe, McLaughlin (2009), Dasgupta, Dighe, Raffelt, Smirnov,
PRL103(2009) , Dasgupta, Mirizzi, Tamborra, Tomas, PRD81 (2010), Fogli, Lisi, Marrone,
Tamborra, JCAP0910(2009), … …
nn interaction
R. C. Schirato and G. M. Fuller (2002), arXiv : , C. Lunardini and A. Y. Smirnov, JCAP 0306, 009 (2003), , K. Takahashi, K. Sato, H. E. Dalhed, and J. R. Wilson, Astropart. Phys. 20, 189 (2003), , G. L. Fogli, E. Lisi, A. Mirizzi, and D. Montanino, Phys. Rev. 68, (2003), , R. Tomas, M. Kachelrieß, G. Raffelt, A. Dighe, H.-T. Janka, and L. Scheck, JCAP 0409, 015 (2004), , G. L. Fogli, E. Lisi, A. Mirizzi, and D. Montanino, JCAP 4, 2 (2005), , S. Choubey, N. P. Harries, and G. G. Ross, Phys. Rev. D74, (2006), , B. Dasgupta and A. Dighe, Phys. Rev. 75, (2007), , S. Choubey, N. P. Harries, and G. G. Ross, Phys. Rev. 76, (2007), , J. P. Kneller, G. C. McLaughlin, and J. Brockman, Phys. Rev. 77, (2008), ,J. P. Kneller and G. C. McLaughlin, Phys. Rev. 73, (2006), , S.Galais, J.Kneller, C.Volpe and J.Gava, PRD(2010), ...
shock waves
Loreti et al, PRD 52 (1995); Balantekin et al, PRD 54 (2006), Friedland and Gruzinov, hep/ , Fogli et al JCAP 0606 (2006);. Kneller ,arXiv: , J. P. Kneller and C. Volpe, PRD (2010), arXiv: , …
Turbulence

6. The n-n interaction effects
J. Pantaleone, PLB 287 (1992), Samuel,PRD 48 (1993), Sigl and Raffelt, NPB 406 (1993).
a non-linear problem,
involved numerically
H = Hvacuum + Hmatter + Hnn (rn)
Balantekin and Yuksel New J. Phys. 7 (2005)
Duan,Fuller,Qian PRD74 (2006)
Important progress since 2006 :
Introduce neutrino flavour conversion near the neutrinosphere
Distance in SN
n e Survival Probability 1 2 3
Three regimes identified :
1- The synchronization regime
2- The bipolar oscillations
3- The spectral split
Duan,Fuller,Qian PRD74 (2006),
Hannestad, Raffelt, Sigl, Wong, PRD 74 (2006),
Raffelt,Smirnov, PRD 76 (2007)
Many questions remain open…

7. The matter basis point of view :
the role of the matter phase derivative
S. Galais, J. P. Kneller , C. Volpe, arXiv:
In 2n flavors the U matrix in matter :
matter phase
matter angle
It involves the
derivative of the
matter phase.
The n
evolution
equation
H11-H22
Distance in SN (km)
onset of flavour conversion
The onset of bipolar
oscillations due to
a rapid growth of
the phase derivative.

8. The spectral split phenomenon
The neutrino fluxes are
significantly modified.
Inverted
hierarchy ne
Duan, et al.
PRD 74 (2006)
Spectral-split
Duan, Fuller, Qian, PRD76(2007)
Raffelt and Smirnov PRD 76 (2007),
PRL 2007 (L cons.)
Dasgupta, Dighe, Raffelt, Smirnov, PRL103(2009)
(multiple splits), Dasgupta, Mirizzi, Tamborra,
Tomas, PRD81 (2010), Fogli, Lisi, Marrone, Tamborra, JCAP0910(2009),…
Many features identified,
however the underlying mechanism
not fully unravelled…
The neutrino evolution with the neutrino polarization vectors : the precession of an effective spin around an effective magnetic field.
Example : Flavor basis
Polarization vector formalism

9. The spectral split: a magnetic resonance phenomenon
Matter
basis
Galais and Volpe, to appear. w w0
Flavour basis
The magnetic resonance phenomenon
is the spin inversion occurring when
the frequency of the magnetic field
in the plane is close to the spin
precession frequency around Bz.
The Magnetic Resonance condition :
w-w0 = 0
A NEW UNDERSTANDING OF THE SPECTRAL SPLIT.

10. CP violation effects in supernovae
First studied in :
Akhmedov, Lunardini & Smirnov, Nucl.Phys.B643 (2002) 339.
Balantekin, Gava, Volpe, PLB662, 396 (2008), arXiv:
Gava, Volpe, Phys. Rev. D78, (2008), arXiv:
Recently it has been shown that :
You need e.g. differences in the nm
and nt interaction with matter
(due to radiative corrections and
physics beyond the standard model
such as FCNC, …).
THERE CAN BE CP-VIOLATION EFFECTS IN SUPERNOVAE.
Modifications of the neutrino fluxes small (5-10%).
Kneller and McLaughlin, PRD 80, (2009) arXiv:
Analytical results (without neutrino-neutrino interaction) confirmed in :

11. Unknown n-properties and supernovae
Neutrinos from supernovae can offer a tool to extract information on key unknown neutrino properties :
The third neutrino mixing angle
The mass hierarchy
If these are determined in future experiments,
neutrinos can tell us about what occurs in the
stellar interior.
Several other key unknown neutrino properties have an impact in the supernova context :
Sterile neutrinos
LFV interactions, …

12. Observations Different observations complementary. Future explosions
Nucleosynthesis
We would like to
measure the
luminosity curve
from a future
(extra)galactic
explosion with
observatories
running and future
large size detectors.
Neutrinos play a key
role in various
nucleosynthesis
processes, in
particular the
r-process or the
neutrino process.
THE DSNB
We want to observe
the diffuse
supernova neutrino
background
- Gd-doping and
Megaton detectors .
Different observations complementary.

13. Impact on nucleosynthesis of the nn int.
Yuksel and Balantekin,
New J.Phys.7, 51(2005).
Effect on the neutron/proton ratio
Duan, Friedland, McLaughlin, Surman
JPG 38, (2010)
Chakraborty, Choubey,
Goswami, Kar, JCAP 1006,
007 (2010), arXiv:

14. An imprint of the shock on the time signal,…
An imprint of the shock on the time signal,
depending on n-properties
ne + p n + e+
POSITRON TIME SIGNAL
First calculation including
the n-n interaction and
shock wave effects.
IF sin22q13 > 10-5
inverted hierarchy
FLUXES
ON EARTH
adiabatic
non-adiabatic
29 MeV
15 MeV
Gava, Kneller, Volpe, McLaughlin,
PRL 103 (2009), arXiv:
The bump (dip) can be seen at 3.5 (1) sigma in
Super-Kamiokande if a supernova at 10 kpc explodes..

15. Important to have different energy thresholds.
The HALO project
80 tonnes of Pb, HALO-2: 1kt
Information on the fluxes at the
neutrinosphere can be extracted :
a test of SN simulations
Neutrino fluxes at
the neutrinosphere
Equal L
C. Volpe et, D. Vaananen to appear.
Important to have different energy thresholds.

16. ne detection : n-nucleus cross sections necessary
to determine the supernovae observatories’s responses
HALO, LENA, GLACIER, MEMPHYS
208Pb
12C
40Ar
16O

17. Low energy neutrino-nucleus cross section uncertainties
AN EXAMPLE
1.16
1.26
1.24
1.4 .
Ratio of flux-averaged cross sections
2/1
3/1
Neutrino-lead calculations used
for the comparison:
1- J.Engel, et al. PRD 67, (2003) RPA
2- E. Kolbe et al., PRC 63, (2001) CRPA
3- N. Paar (priv. communication) relativistic RPA
Neutrino-nucleus cross section measurements welcome…
also useful for double-beta decay (ga, forbidden,…)

18. POSSIBLE FUTURE INTENSE n SOURCES
m+ + nm
at SPALLATION SOURCES m+
e + nm + ne
Future facilities : SNS, ESS, JSNS, SPL
Low energy BETA-BEAMS PS
SPS E U R I S O L
storage
ring n
close
detector
C.Volpe, J Phys G 30 (2004) L1.
6Li ne
Beta-beam feasibility
EURISOL DS (FP6), EURONU (FP7)
A proposal to establish a facility for the production of intense and pure low energy neutrino beams in the 100 MeV energy range.
A small storage ring (g=1) soon at CERN?

19. Conclusions and Perspectives
For the next (extra)galactic supernova explosion
(and the DSNB discovery), it is very important to
have a detectors….
sensitive to both electron anti-neutrinos and electron neutrinos.
besides to neutral current.
with different energy thresholds, in particular
for the ne : argon-based (5 MeV), lead-based (10, 20 MeV),
scintillators and Cherenkov (about 20 MeV).
with good time resolution or time and energy resolution.
at least one large size (megaton) detector.

20. Conclusions and Perspectives
Supernova explosion on the way…
Neutrino flavour conversion processes
in such explosive media has really
increased in complexity.
In the long run these two descriptions
should merge…
The SN neutrino fluxes encode
information on n-properties
and supernova dynamics :
A lot to learn from future observations !

21. Danke.
Gracias
Thank you
Grazie
Life tree
Merci

22. Turbulence effects NEUTRINOS CAN COMPLETELY MIX («depolarize »).
Loreti et al, PRD 52 (1995); Balantekin et al, PRD 54 (1006); Friedland and Gruzinov, hep/ , Fogli et al JCAP 0606 (2006);. Kneller arXiv:
First calculation of instantations of
the neutrino amplitudes- not of
average probabilities - in presence
of shock waves and turbulence.
NEUTRINOS CAN COMPLETELY
MIX («depolarize »).
TRANSITION FROM shock-wave
to turbulence dominated
regime, as the fluctuation
amplitude increases.
Kneller and Volpe, PRD (2010) , arXiv:

24. The matter basis point of view : the phase derivative role
S. Galais, J. P. Kneller , C. Volpe, arXiv:
In 2n flavors the matter Hamiltonian :
Synch.
Bipolar osc.
The phase
derivative
contributes
to diagonal
& off-diagonal
terms.
H12
H*12
H11
H22 H
H11-H22
Distance in SN (km)
|H12|
Distance in SN (km)
The matter phase non-zero
since the nn interaction
hamiltonian has complex
off-diagonal terms.

25. POSSIBLE FUTURE INTENSE n SOURCES
at SPALLATION SOURCES p+
m+ + nm ne m+
e + nm + ne
Future sites : SNS, ESS JSNS, SPL
F. Avignone, Y Efremenko, (SNS) JPG 29, 2615 (2003).
R. Lazauskas, C. Volpe, JPG 37,
(2010), arXiv :
12C
40Ar
16O
208Pb
56Fe
1470
384
998
261
8860
2310
9100
2330
34500
8820 10 20
D (m)
EVENTS (3 107 s)
Expected rates in a detector
at different distances from
the source. ne /s
1 ton cubic detector
Low energy BETA-BEAMS PS
SPS E U R I S O L
storage
ring n
close
detector
C.Volpe, J Phys G 30 (2004) L1.
6Li ne
Beta-beam feasibility studied
EURISOL DS (FP6), EURONU (FP7)

26. Low energy neutrino-nucleus cross section uncertainties AN EXAMPLE
Neutrino fluxes
(power law)
ane
AN EXAMPLE
Neutrino-lead calculations used
for the comparison:
1- J.Engel, et al. PRD 67, (2003) RPA
2- E. Kolbe et al., PRC 63, (2001) CRPA
3- N. Paar (priv. communication) relativistic RPA
1.16
1.26
1.24
1.4
Volpe and
Vaananen
to be submitted.
Ratio of flux-averaged cross sections
2/1
3/1