Damping of neutrino flavor conversion in the wake of the supernova shock wave
Neutrino Flavor Transformation : hot neutron stars to...
Transcript of Neutrino Flavor Transformation : hot neutron stars to...
George M. FullerDepartment of Physics
&Center for Astrophysics and Space Science
University of California, San Diego
Neutron Stars and Neutrinos Arizona State University
Tempe, AZApril 12, 2010
Geor ge M. Ful l erDepar t ment of Physi cs
Neutrino Flavor Transformation :hot neutron stars
to the early universe
Neutrino mass physics is a theme common to both
Compact Objects (supernovae; neutron stars; holes; etc. . .)
Cosmology (structure formation; dark matter, etc. . .)
Synergy between laboratory/observational neutrino physicsand new developments and capabilitiesin observational astronomy
We have an exciting situation in neutrino physics and astrophysics
Experiment s are revealing t he propert ies of neut rinosand t his new dat a is driving int erest ing development sin nuclear and part icle ast rophysics. As I will show,t hese ast rophysical development s may feed back onour underst anding of neut rino propert ies.
This is classic particle/nuclear astrophysics,with a synergistic coupling of astrophysicsand low energy laboratory measurementsof physics beyond the Standard Model
Willy Fowler might appreciate this . . .
We know the mass-squared differences:
We do not know the absolute masses or the mass hierarchy:
Neutrino Mass: what we know and don’t know
We know 2 of the 4 vacuum 3X3 mixing parametersand we have a good upper limit on a third.
Neutrino energy (mass) states are not coincidentwith the weak interaction (flavor) states
The unitary transformation that relates these statesin vacuum has 4 parameters (exclusive of Majorana phases)
δm232 ≈ 2.4 ×10−3 eV2
sin2 θ23 ≈ 0.50Atmospheric Neutrinos
“Solar”/KamLaND Neutrinos
δmsol2 ≈ 7.6 ×10−5 eV2
sin2 θ12 ≈ 0.31
The key mixing angle
limit on θ13 ⇒
sin2 θ13 < 0.040 ( 2σ)
My take on this is as follows:
(1) What we already know about neutrino mass/mixing has potentially big implications for astrophysics.
(2) Working out those implications may allow new insights into nucleosynthesis and unmeasured neutrino properties:e.g., a supernova neutrino signal could help us get at θ13 andthe neutrino mass hierarchy. And, vice versa, what we know aboutneutrino flavor mixing may give us insights into how supernovae work.Cosmology may give absolute masses --- gives best limits now.
MASS Main Seq.Entropy per baryon
CollapseEntropy per baryon
Iron core mass
Instability Mechanism
Fraction of rest mass radiated as neutrinos
12 to ~ 100 ~ 10 ~ 1 ~ 1.4
Electron capture /Feynman-ChandrasekharG.R. instab.
~ 10%Iron core mass
~ 100 to
~ 104~ 100 ~ 100 NONE pair
instability
~ 10%C/O burning core
~ 104
to~ 108
~ 1000no main seq.
~ 1000 NONE
Feynman-ChandrasekharG.R.Instability
~ 5%
Neutrino Trapping /Thermal equilibrium
Yes
Yes
No
Gravitational Collapse of Massive Stars
The Core Collapse Supernova Phenomenonis Exquisitely Sensitive to Flavor ChangingProcesses and New Neutrino Physics:
Gravitational collapse results in high electron and νeFermi Energies (representing ~ 1057 units of e-lepton number);µ/τ charged leptons are absent and the correspondingneutrinos are pair-produced so they carry no net lepton number.Any process that changes flavor νe νµ/τ/s will open phasespace for electron capture as well as reducing e-lepton number.
Later, energy (10% of the core’s rest mass) is in seas of activeneutrinos of all flavors. Entropy and lepton number transportedby neutrinos.
Neutron/proton ratio (crucial for nucleosynthesis) determinedby electron degeneracy or by charged current neutrino capture:
Neutrinos Dominate the Energetics of Core Collapse Supernovae
Total optical + kinetic energy, 1051 ergs
Total energy released in Neutrinos, 1053 ergs
Neutrino diffusion time,
τν ≈ 2 s to
10 s
Lν ≈16
GMNS2
RNS
1τν
≈ 4 ×1051ergs s-1
Explosiononly ~1% of
neutrino energy
10% of star’srest mass!
EGRAV ≈35
G MNS2
RNS
≈ 3 ×1053ergs MNS
1.4Msun
210 km
RNS
ordinary MSW evolution of neutrino flavors
MSW resonance at neutrino energy
Eν =δm2 cos2θ2 A + B( )
≈ 0.02 MeV( ) δm2 cos2θ3×10−3 eV2
106 g cm-3
ρ Ye + Yν( )
sin2 2
θ MEν(MeV)
“coherent”λmfp>>res. width
λmfp <<res. width“incoherent”
ν e = cosθM t( )ν1 t( ) + sinθM t( )ν 2 t( )ντ = −sinθM t( )ν1 t( ) + cosθM t( )ν 2 t( )
time/position - dependentmixing angle and mass-states
At a given location expect only neutrinosin a narrow energy range to experience largeflavor mixing while anti-neutrino mixing is suppressed. With the small measuredneutrino mass-squared differences we expectsignificant flavor conversion only at low densities.
Neutrino Self Coupling - the source of nonlinearity
Coherent Flavor Evolution for Neutrino i
neutrino-electroncharged currentforward exchange scattering
neutrino-neutrinoneutral currentforward scattering
Effects beyond the mean field?Balantekin & Pehlivan (2007)Friedland & Lunardini (2003)
now self-consistently couple flavor evolution
on all neutrino trajectories . . . • Anisotropic, nonlinear quantum coupling of
all neutrino flavor evolution histories
Neutrino flavor evolutionin core collapse supernovae
Huaiyu Duan (UCSD/INT), George M. Fuller (UCSD)Joseph A. Carlson (LANL),Yong-Zhong Qian (U. Minn.)
(numerical simulations/analyses with coupled trajectories)
“Coherent Development of Neutrino Flavor in the Supernova Environment,”H. Duan, G.M. Fuller, J. Carlson, Y.-Z. Qian, Phys. Rev. Lett. 97, 241101 (2006)“Simulation of coherent nonlinear neutrino flavor transformation in the supernova environment:Correlated neutrino trajectories,”
H. Duan, G.M. Fuller, J. Carlson, Y.-Z. Qian, Phys. Rev. D 74, 105014 (2006)“Analysis of Collective Neutrino Flavor Transformation in Supernovae,”H. Duan, G.M. Fuller, J. Carlson, Y.-Z. Qian, Phys. Rev. D 75, 125005 (2007)
“Neutrino Mass Hierarchy and Stepwise Spectral Swapping of Supernova Neutrino Flavors,”H. Duan, G.M. Fuller, J. Carlson, Y.-Z. Qian, Phys. Rev. Lett. 99, 241802 (2007)
“A Simple Picture for Neutrino Flavor Transformation in Supernovae,”H. Duan, G.M. Fuller, & Y.-Z. Qian, Phys. Rev. D 76, 085013 (2007)
“Collective neutrino flavor transformation in supernovae,”H. Duan, G.M. Fuller, & Y.-Z. Qian, Phys. Rev. D 74, 123004 (2006)
“Simultaneous flavor transformation of neutrinos and antineutrinos with dominant potentialsfrom neutrino-neutrino forward scattering,”
G.M. Fuller & Y.-Z. Qian, Phys. Rev. D 73, 023004 (2006)
“Flavor Evolution of the Neutronization Neutrino Burst from an O-Ne-Mg Core Collapse Supernova,”H. Duan, G.M. Fuller, J. Carlson, Y.-Z. Qian, Phys. Rev. Lett. 100, 021101 (2008)“Stepwise Spectral Swapping with Three Neutrino Flavors,”H. Duan, G.M. Fuller, Y.-Z. Qian, Phys. Rev. D 77, 085016 (2008) “Simulating Nonlinear Neutrino Flavor Transformation,” H. Duan, G.M. Fuller, J. Carlson, Y.-Z. Qian, Computational Science & Discovery, 1, 015007 (2008)
Some other recent work on neutrino flavor evolutionin core collapse supernovae
S. Hannestad, G.C. Raffelt, G. Sigl, & Y.Y.Y. Wong, Phys. Rev. D 74, 105010 (2006)astro-ph/0608695 (the “flavor pendulum”)
G.C. Raffelt & G. Sigl astro-ph/0608695
J.P. Kneller, G.C. McLaughlin, & J. Brockman, astro-ph/0705.3835
S. Pastor & G.C. Raffelt, Phys. Rev. Lett. 89, 191101 (2002)
A. Dolgov, S. Hansen, S. Pastor, S. Petcov, G. Raffelt, P. Semikoz hep-ph/0201287
K. Abazajian, J. Beacom, N. Bell astro-ph/0203442
G.C. Raffelt & A.Y. Smirnov, hep-ph/0705.1830
Ot her gr oups now have “ mul t i - angl e” codes . . .A. Esteban-Pretel, S. Pastor, R. Tomas, G.C. Raffelt, G. Sigl, astro-ph/0706.2498
G. Fogli, E. Lisi, A. Marrone, A. Mirizzi, hep-ph/0707.1998
A.B. Balantekin & H. Yuksel, New J. Phys. 7, 51 (2005)
R. F. Sawyer, Phys. Rev. D 72, 045003 (2005)
A. Friedland, B.H.J. McKellar, I. Ocuniewicz, Phys. Rev. D 73, 093002 (2006)
A. Friedland and C. Lunardini, J. High Energy Phys. 10, 043 (2003)
A great deal of work has now been done on this problem by many groups around the world.There is now a huge literature on this topic.See review on Collective Neutrino Oscillations:
H. Duan, G. M. Fuller, & Y.-Z. Qian, hep-ph/1001.2799
Results of Large-Scale Numerical Calculations
In the sample numerical calculations that follow we have taken:
The neutrino mass-squared difference to be
The effective 2 X 2 vacuum mixing angle to be either
The neutrino energy luminosities to be the same for all species and either
oras indicated.
for the NORMAL MASS HIERARCHY
for the INVERTED MASS HIERARCHY
neutrinos antineutrinos
r6 radius in units of 106 cm
cosi
ne o
f em
issi
on a
ngle
angl
e-av
erag
eden
ergy
spe
ctra
NO
RM
AL M
ASS H
IERA
RC
HY
neutrinos antineutrinos
r6 radius in units of 106 cm
cosi
ne o
f em
issi
on a
ngle
angl
e-av
erag
eden
ergy
spe
ctra
NO
RM
AL M
ASS H
IERA
RC
HY
neutrinos antineutrinos
r6 radius in units of 106 cm
cosi
ne o
f em
issi
on a
ngle
angl
e-av
erag
eden
ergy
spe
ctra
INVER
TED M
ASS H
IERA
RC
HY
survival probability
cosi
ne o
f ν tr
ajec
tory
ang
le w
rt. n
orm
al to
n.s.
surf
ace
consequences of neutrino mass and quantum coherence in supernovaeH. Duan, G. M. Fuller, J. Carlson, Y.-Z. Qian, Phys. Rev. Lett. 97, 241101 (2006) astro-ph/0606616
normal m
ass hierarchyinverted m
ass hierarchy
Spectral Swap
The νe - νµ/τ Spectral Swap - a mass hierarchy signal ?
nor mal mass hi er ar chy i nver t ed mass hi er ar chy
cosi
ne o
f ne
utri
no e
miss
ion
angl
e
survival probability Pνν
neut r i no ener gy neut r i no ener gy
her e spect r al swap ener gy ECdecr eases wi t h decr easi ng θV
swap has its origin in nonlinear neutrino self- couplingH. Duan, G.M. Fuller, J. Carlson, Y.-Z. Qian, Phys. Rev. Lett. 99, 241802 (2007)
O- Ne- Mg Cor e Col l apse Super novaeThe progenitors of these events are stars in the mass range
K. Nomoto, Astrophys. J., 277, 791 (1984); 322, 206 (1987)
Post-collapse, these objects have a very steep matter densityprofile above the neutron star and behind the (viable) shock.
Modeling flavor transformation in the neutronization burstrequires a full 3X3 mixing treatment with neutrino self-coupling.
We find a sequence of neutrino spectral swaps which, if detected,could identify the neutrino burst as originating in an O-Ne-Mgevent instead of an ordinary Fe-core-collapse!
H. Duan, G.M. Fuller, J. Carlson, Y.-Z. Qian, Phys. Rev. Lett. 100, 021101 (2008)C. Lunardini, B. Mueller, H.-Th. Janka, Phys. Rev. D 78, 023016 (2008)
Full 3X3 treatment (with both atmospheric and solar mass-squared differences) of the neutronization burst from an O-Ne-Mg core collapse: succession of spectral swaps
Distinctive pattern could tell us whether SN is an Fe-core or an O-Ne-Mg core collapse:
H. Duan, G.M. Fuller, J. Carlson, Y.-Z. Qian, Phys. Rev. Lett. 100, 021101 (2008)
squa
red-
ampl
itude
to this end . . . open issues
e.g., the SASI and late re-heating Blondin & Mezzacappa Nature 445, 58 (2007)
Inhomogeneous matter/neutrino environments,e.g., what are the effects of inhomogeneities like turbulence or the shock on the neutrino signal, anisotropic neutrino emission? Friedland & Gruzinov (2006); Gava et al. (2009)Galais, Kneller, Volpe, & Gava (2009); review by H. Duan & J. Kneller (2009)
Full 3X3 flavor transformation in realistic environments,“multi-angle”, phase averaging - necessarye.g., A. Friedland hep-ph/1001.0996 (2010)
Extension to regime where scattering-induced de-coherenceis significant: the full Quantum Kinetic Equations.Abazaj i an, Ful l er , Pat el ( 2001) ; St r ack & Bur r ows (2005)Cardall (2007, 2009); Kishimoto & Fuller (2008)
Non-Spherical geometries . . . 3-D hydro
The experimental revolution in neutrino physics has given us some ofthe mass/mixing properties of the neutrinos. Modelers should include this physics in models of core collapse supernovaeand in the early universe.
Neutrino self coupling can alter neutrino flavor evolution in SN, ultimatelycausing large-scale flavor conversion deep in the supernova envelope,despite the small measured neutrino mass-squared differences. MSW-based analyses are inadequate.This could affect neutrino-heated nucleosynthesis and the neutrino signal.
Neutrino self coupling-induced flavor collective modesmay produce distinctive signatures which could allow a supernova neutrino signal to give us theneutrino mass hierarchy and θ13as well as give us an observational window on the deep interior of the coreand distinguish between Fe-core collapse and O-Ne-Mg core collapse.
CONCLUSIONS