Karlheinz Langanke Erice, September 2009crunch.ikp.physik.tu-darmstadt.de/erice/2009/sec/... · Erice, September 2009 Karlheinz Langanke ( GSI & TU Darmstadt) Supernova neutrino-nucleus

Supernova neutrino-nucleus reactions

Karlheinz Langanke

GSI & TU Darmstadt

Erice, September 2009

Karlheinz Langanke ( GSI & TU Darmstadt) Supernova neutrino-nucleus reactions Erice, September 2009 1 / 25

Contents

supernova neutrinos due to electron capturesinelastic neutrino-nucleus scatteringconsequences for observation of neutrino-burstneutrino nucleosynthesis. . .


Core-collapse supernova.


Electron captures in core collapse.

T = 0.5–2.0 MeV,ρ = 108–1013 g cm−3.The dynamical time scale set byelectron captures:e− + (N,Z )→ (N + 1,Z − 1) + νe

Evolution decreases number ofelectrons (Ye) andChandrasekhar mass(MCh ≈ 1.4(2Ye)2 M)

Capture rates on individual nuclei computed by:Shell Model (A < 65)Shell Model Monte Carlo (A > 65)RPA with parametrized occupation numbers (A > 115)


Gamow-Teller strength distributions in pf-shell nuclei.

(n,p) experiments, TRIUMF

-2 0 2 4 6 8 10 12

E (MeV)

0.0

0.5

1.0

0.0

0.2

0.4

0.6

GT

Str

engt

h

0.0

0.2

0.4

0.6

0.8

1.0

-2 0 2 4 6 8 10 12

E (MeV)

0.0

0.2

0.4

0.6

0.0

0.2

0.4

0.0

0.1

0.2

0.3

0.4

0.5

56Fe

54Fe

58Ni

51V

55Mn

59Co

FFNExpSM

(d,2He) experiments, KVIGroningen

B(G

T+ )

dσ/

dΩ

[mb

/(sr

50

keV

)]

51V(d,2He)51Ti Elab=171 MeV Θcm<1˚

Shell -Model Calculation

Ex [MeV]

Ex [MeV]

2.14

MeV

3.62

MeV 4.

88 M

eV

shell model results agree after overall quenching by (0.77)2


Effect on improved rates on collapse simulations

With Rampp & Janka (General Relativistic model)15 M presupernova model from A. Heger & S. Woosley

1010 1011 1012 1013 1014

ρc (g cm−3)

0.20

0.25

0.30

0.35

0.40

0.45

Ye,

c, Y

lep,

c

BruennLMSH

Ylep

Ye

1010 1011 1012 1013 1014

ρc (g cm−3)

10−1

100

101

102

103

104

105

106

Eν−

emis

sion

(M

eV s−

1 )

BruennLMSH

1010 1012 1014

ρc (g cm−3)

0

10

20

30

40

50

⟨Eν⟩

(M

eV)


Bounce and shock wave evolution
















’Standard’ core trajectory at bounce

109 1010 1011 1012 1013 1014 10150.2

0.3

0.4

0.5

Ye

ρ [g/cm3]

Ylep + 0.03

Ye

s11-SLMSH

s15-SLMSH

s20-SLMSH

s25-SLMSH

Electron captures on nuclei and protons are self-regulating leading tothe same trajectories at bounce for different stellar masses(H.Th. Janka, A. Marek, G. Martinez-Pinedo)


’Standard’ neutrino burst

-10 0 10 20 0

100

200

300

400

50 100 150 200

t [ms]

Lν e

[1051

erg/

s]

s11-SLMS

s15-SLMS

s20-SLMS

s25-SLMS

shock dissociates matter into free protons and neutronsfast electron captures on free protons create νe neutrino burst’standard’ νe burstsfuture observation by supernova neutrino detectors’standard neutrino candles’?


Inelastic ν-nucleus scattering in supernovae

Potential consequences:thermalization of neutrinosduring collapsepreheating of matter beforepassing of shocknucleosynthesis, νp-processsupernova neutrino signal

0 5 10 15 20 25 30 35 40Neutrino Energy (MeV)

10−4

10−3

10−2

10−1

100

101

102

103

σ (1

0−42

cm

2 )

Only GS (SDalinac data)Only GS (Theory)T = 0.8 MeV

52Cr

neutrino cross sections from(e,e′) datavalidation of shell modelG.Martinez-Pinedo, P. v.Neumann-Cosel, A. Richter


Supernova neutrino signal

inelastic ν-nucleus scattering adds to the opacity for high-energyneutrinos

0 10 20 30 40 50 60 70E/MeV

1e-08

1e-06

0.0001

0.01

1J ν/ ∫

J ν dE

without inelastic scattering on nuclei (ISN)with ISN (Y

heavy from LS-EOS)

Normalized Burst Spectra(r=400km, electron neutrinos)

B. Müller, H.-Th. Janka, G. Martinez-Pinedo, A. Juodagalvis, J.Sampaio


Consequences for supernova neutrino detectors

Detector Material 〈σ〉 (10−42 cm2) ChangeWith A(ν, ν′)A? Without A(ν, ν′)A?

SNO d 5.92 7.08 16%MiniBoone 12C 0.098 0.17 43%

12C (Ngs) 0.089 0.15 41%S-Kamiokande 16O 0.013 0.031 58%Icarus 40Ar 17.1 21.5 20%Minos 56Fe 8.8 12.0 27%OMNIS 208Pb 147.2 201.2 27%

Change in supernova neutrino spectra reduce detection rates!


Neutrinos from supernovae

Raffelt et al., astro-ph/0303226Traditional Improved

Neutron−rich matter

ν− ν

νe+ n p + e−

νe+ p n + e− +

R ~ 1/T

νx

−eν

νe (E ~ 13 MeV)

(E ~ 23 MeV)

(E ~ 13 MeV)

(E ~ 16 MeV) (E ~ 17 MeV)

(E ~ 18 MeV)

neutrino detection (SN1987A)

0.0 5.0 10.0 15.0Time (seconds)

0.0

10.0

20.0

30.0

40.0

50.0

Ene

rgy

(MeV

)

Kamiokande IIIMB

Neutrino nucleosynthesis12C(ν, ν′p)11B 12C(ν, ν′n)11C

ν

ν′ν

ν′

p

n


Neutrino nucleosynthesis

A. Heger et al, PLB 606 (2005) 258

Product Parent Reaction11B 12C (ν, ν′n), (ν, ν′p)19F 20Ne (ν, ν′n), (ν, ν′p)

138La 138Ba (νe, e−)139La (ν, ν′n)

180Ta 180Hf (νe, e−)181Ta (ν, ν′n)

11B 19F 138La 180Ta10−3

10−2

10−1

100

101

Pro

duct

ion

Fac

tor

rela

tive

to 16

O

15 M without ν15 M with ν25 M without ν25 M with ν


Importance of 138La and 180Ta nucleosynthesis

11B and 19F are produced by neutral-current reactions induced byνµ and ντ neutrinos and anti-neutrinosνe neutrinos observed from SN1987a138La and 180Ta are produced by charged-current reactionsinduced by νe neutrinos on 138Ba and 180HfIn summary, one has a sensitivity to ALL different neutrino spectra

However, neutrino cross sections based on theoretical models (RPA)


Measurement of GT strength for 138Ba and 180Hf

RCNP Osaka/ Darmstadt (A.Byelikov et al.)

11B 19F 138La 180Ta10−3

10−2

10−1

100

101

Pro

duct

ion

Fac

tor

rela

tive

to 16

O

15 M⊙ without ν15 M⊙ with ν25 M⊙ without ν25 M⊙ with ν


Summary

Improved nuclear ingredients for supernova simulationsElectron capture rates on nuclei change collapse trajectoryNeutrino-nucleus cross sections have impact on neutrino-burstsignalNeutrino-nucleosynthesis might serve as neutrino thermometer


Documents

Karlheinz Langanke Erice, September 2009crunch.ikp.physik.tu-darmstadt.de/erice/2009/sec/... · Erice, September 2009 Karlheinz Langanke ( GSI & TU Darmstadt) Supernova neutrino-nucleus