Exotic nuclei and explosive nucleosynthesis
Gabriel Martínez Pinedo
ISOLDE workshop & users meeting November 25-27, 2013, Cern
Nuclear Astrophysics Virtual Institute Electron capture in Core-collapse supernova Heavy-element nucleosynthesis: The r-process Summary Outline
1 Electron capture in Core-collapse supernova
2 Heavy-element nucleosynthesis: The r-process
3 Summary Electron capture in Core-collapse supernova Heavy-element nucleosynthesis: The r-process Summary Weak interactions during collapse
R [km] Neutrino Trapping Composition of Iron group and
(t ~ 0.1s, cδ ~10¹² g/cm³) RFe heavier nuclei ν e Dominanting process, electron
capture on nuclei: ν e ~ 100 e−+A(Z, N) A(Z 1, N+1)+ν e − Si Dominated by Gamow-Teller Fe, Ni ν e transitions. Evolution decreases the number M(r) [M ] 0.5 Mhc 1.0 of electrons (Ye) and heavy nuclei Chandrashekhar mass Si−burning shell 2 (Mch = 1.4(2Ye) M )
15 15 Laboratory 15 Supernova 10 10 10 5 Low−lying Strength 0 Gamow−Teller 5 5 Resonance σ τ+ electron distribution (Z,A) 0 0 (Z−1,A) (Z,A) (Z−1,A) Electron capture in Core-collapse supernova Heavy-element nucleosynthesis: The r-process Summary Early composition
Initially the composition is mainly given by Iron group nuclei.
log X 0 9 •3 50 T = 9.01 GK, ρ = 6.80 × 10 g cm , Ye = 0.433 •1
40 •2
•3 30 •4
20 •5 Proton number •6 10 •7
0 •8 0 10 20 30 40 50 60 70 80 Neutron number
GMP, M. Liebendörfer, D. Frekers, NPA 777, 395 (2006). Electron capture in Core-collapse supernova Heavy-element nucleosynthesis: The r-process Summary Shell-model based electron capture rates
0 56 10 56 C. Bäumer et al. PRC 68, 031303 (2003) -3 10 Fe Ni )
+ 0.4 -6 -1 51 2 51 10 10 V(d, He) Ti -9 B(GT 0.3 10 LMP -2 -12 FFN 10 10 ρ =10.7 ρ =4.32 0.2 -15 7 7 10 -3 55 10 59 -1 0 Co Co 0.1 10 10
) -2
1 -1 10 − 10 -3
(s 10 -2 ec 10 -4 λ 10 -3 10 ρ -5 ρ 7=4.32 10 7=33 0.1 -4 -6 10 54 10 60 Mn Co -1 0 0.2 10 10
-2 -2 ) 10 10 + 0.3 large shell model -3 -4 calculation 10 ρ 10 ρ 7=10.7 7=33
B(GT 0.4 -4 -6 10 10 0 1 2 3 4 5 6 7 1 4 7 10 1 4 7 10 T T Ex [MeV] 9 9 Capture rates on iron group nuclei calculated by large scale shell-model (Langanke & GMP, 2000) Capture rates are noticeable smaller than assumed before Electron capture in Core-collapse supernova Heavy-element nucleosynthesis: The r-process Summary Systematic study measured GT strengths
A. L. Cole et al., PRC 86, 015809 (2012)
7 3 (a) 9 3 (b) 2 ρYe=10 g/cm ρYe=10 g/cm 10 GXPF1a (KB3G) T=3x109 K (KB3G) 5 T=10x109 K EC KB3G EC λ λ
/ QRPA / EC EC λ 10 (n,p) λ (d,2He)
(t,3He) 1 (p,n) T> 1
-1 10 0.5 V V V V Ti Ti Ni Ni Ni Ni Ni Ni Ni Ni Zn Zn Fe Fe Fe Fe Sc Sc Co Co Mn Mn 50 51 50 51 48 48 60 62 64 60 62 64 58 58 64 64 56 56 54 54 45 45 59 59 55 55
Rates for iron-group nuclei are under control With increasing density, less sophisticated models like QRPA may suffice. Electron capture in Core-collapse supernova Heavy-element nucleosynthesis: The r-process Summary Late time composition
With decreasing Ye the composition moves to more neutron rich nuclei.
log X 0 11 •3 50 T = 17.84 GK, ρ = 3.39 × 10 g cm , Ye = 0.379 •1
40 •2
•3 30 •4
20 •5 Proton number •6 10 •7
0 •8 0 10 20 30 40 50 60 70 80 Neutron number
GMP, M. Liebendörfer, D. Frekers, NPA 777, 395 (2006). Electron capture in Core-collapse supernova Heavy-element nucleosynthesis: The r-process Summary Challenge: electron capture around N=40
Independent particle treatment g9/2 Unblocked g9/2 Correlations N=40 Finite T f Blocked 5/2 GT p GT f5/2 1/2 p p 1/2 3/2 p3/2 f7/2 neutrons protons f7/2 neutrons protons Core Core Langanke & GMP, RMP 75, 819 (2003) Fuller, ApJ 252, 741 (1982) Electron capture in Core-collapse supernova Heavy-element nucleosynthesis: The r-process Summary Correlations around N=40: GT+ strength for 76Se
The structure of 76Se (Z = 34, N = 42) has been the subject of several recent studies due to its important for the double beta decay of 76Ge Measured occupation numbers in transfer reactions Schiffer et al, PRL 100, 112501 (2008) Kay et al, PRC 79, 021301(R) (2009)
10 10 EXP EXP SM SM 8 76Se 8 76Se
6 6
4 4
2 2 Proton Occupancy Neutron Occupancy 0 0 p f g p f g
Occupation of g9/2 orbital is larger than naive IPM estimates. Electron capture in Core-collapse supernova Heavy-element nucleosynthesis: The r-process Summary Correlations around N=40: GT+ strength for 76Se
Gamow-Teller strength measured in charge-exchange reactions: (d, 2He): Grewe et al., PRC 78, 044301 (2008)
100
10 -3
1.5
= 10 g cm Ye = 0.45
T=2
T=4
T=6
T=8
10
Full
1.0
2 )
Exp.(d, He) -1 (s
ec
B(GT+) T=2
1 T=4
0.5
T=6
T=8
Full
2
Exp.(d, He)
0.1
0.0
4 6 8 10 12 14 16 18 20
0 2 4 6 8 10
Temperature (GK) Excitation energy (MeV) Slow convergence of cross-shell correlations. Thermofield dynamics or finite temperature QRPA models, which consider only 2p-2h (T=2) correlations, do not suffice. What is the role of the N = 40 (Z . 26) island of inversion on electron capture rates? Zhi, Langanke, GMP, Nowacki, Sieja, NPA 859, 172 (2011) Electron capture in Core-collapse supernova Heavy-element nucleosynthesis: The r-process Summary Electron capture supernova
Low mass stars ( 9 M ) develop an ONeMg core during the evolution ∼ that becomes unstable due to electron captures. Particularly important is electron capture on 20Ne. The rate is basically known experimentally except for an unknown second-forbidden ground-state ground-state transition.
0
Takahara et al. Decay Scheme −5 2+ 2+ 2+ → 3+ 2+ 0.0 11.163 s Intensities: Iγ per 100 −10 + + 2 0 parent decays → 9F11 )] 0 2 + + −1 0 → 1 %B–=100 Q –(g.s.)=7024.538 (s −15 Total→ ec 0.0082
λ
[ −20
10 0.00005
log −25 [M2][E1+M2+E3] 99.9995
Iβ – L o g ft
4965.853332.54 [E2] −30 0.0082 7.20 2– 4966.51
1633.602 −35 99.9913 4.9697 2+ 1633.674 9 9.2 9.4 9.6 9.8 10 <0.001 >10.5 0+ 0.0 Y −3 2 0 log10 [ρ e (g cm )] 1 0Ne10 Electron capture in Core-collapse supernova Heavy-element nucleosynthesis: The r-process Summary Making Gold in Nature: r-process nucleosynthesis
250 Known mass Known half−life r−process waiting point (ETFSI−Q)
100 200 98 96
94
92
90
88 Solar r abundances 86 84 188 190 186 82
80
78 184 180 182 76 178 176 74 164 166 168 170 172 174 150 72 162 70 160 N=184 68 158
66 156 154 64 152 150 62 140 142 144 146 148 1 60 138 134 136 58 130 132 0 128 10 56 54 126 124 10 −1 52 122 The r-process requires the knowledge of 120 50 116 118 10 −2 48 112 114 110 46 −3 108 10 100 106 N=126 44 104 the properties of extremely 100 102 42 10 98 96 40 92 94
38 88 90 86 84 r−process path 36 82 neutron-rich nuclei: 34 80 78 32 74 76
30 72 70 28 66 68 64 26 62 N=82 28 60 30 32 34 36 38 40 42 44 46 48 50 52 54 56 58 Nuclear masses. Beta-decay half-lives. Neutron capture rates. Fission rates and yields. Electron capture in Core-collapse supernova Heavy-element nucleosynthesis: The r-process Summary Neutrino-driven winds
Neutrino cooling and Neutrino-driven wind 105 Main processes:
ν , ν 104 e,µ,τ e,µ,τ ν + n p + e−
e m
+ in k ν¯ + p n + e R Ni e 103 Si
He Neutrino interactions determine the 102 νp-process ν , –ν r-process O e,µ,τ e,µ,τ proton to neutron ratio. Rns ~10
Rν PNS Neutron-rich ejecta: 1.4 α, p α, p, nuclei 3 M(r) in M n, p α, n α, n, nuclei h i si)particles that move in a mean-field potential n,p e . Lν¯e E E > 4∆ 1 E 2∆ 2 ν¯e νe np Lν ν¯e np pn h i − h i − e − h i − En = + mn∗ + Un 2mn∗
µn µe
Neutron-richness related to 2 pp Ep = + m∗p + Up nuclear symmetry energy 2m∗p [GMP, Fischer, Lohs, Huther 2012;
Q = m∗ m∗ + U U Roberts, Reddy, Shen 2012] n − p n − p
µp Electron capture in Core-collapse supernova Heavy-element nucleosynthesis: The r-process Summary Constrains in the symmetry energy
Energy per nucleon for neutron matter determined by χEFT at N3LO order (Tews et al 2013, Krüger et al 2013). Symmetry energy constrained by χEFT and nuclear physics experiments and astronomical observations (Lattimer & Lim 2013)
ρ (1014 g cm−3) 0.0 0.5 1.0 1.5 2.0 2.5 3.0 30 χEFT (N3LO) 30 RMF (DD2)
20 20 S (MeV)
E/A (MeV) 10 10
0 0 0.00 0.05 0.10 0.15 0.20 0 0.5 1 −3 n (fm ) ρ/ρ0 Electron capture in Core-collapse supernova Heavy-element nucleosynthesis: The r-process Summary
Impact on neutrino luminosities and Ye evolution
Boltzmann transport radiation simulations based on a 11.2 M progenitor.
1052 0.60 0.58 0.56 51 0.54 10 0.52 0.50 0.48 50 Electron fraction 0.46 Luminosity [ergs/s] 10 0 2 4 6 8 10 0 2 4 6 8 10 Time [s] Time [s] 13 100 12 νe 90 11 80 ν¯e /baryon] 70
10 B [MeV]
k 60 i 9 νx
ν 50
E 8 40 h 7 30 6 20 0 2 4 6 8 10 Entropy [ 0 2 4 6 8 10 Time [s] Time [s]
Ye is moderately neutron-rich at early times and later becomes proton-rich. GMP, Fischer, Huther, arXiv:1309.5477 Electron capture in Core-collapse supernova Heavy-element nucleosynthesis: The r-process Summary Nucleosynthesis
107 106 105 104 103 102 101 100 10-1 10-2 Rel. abundance 10-3 10-4 50 60 70 80 90 100 110 Mass number A 10-2 10-3 10-4 10-5 10-6 10-7 10-8 10-9 Elemental abundance 25 30 35 40 45 50 55 Charge number Z
Elements between Zn and Mo, including 92Mo, are produced Mainly neutron-deficient isotopes are produced. No elements heavier than Mo (Z = 42) are produced. Electron capture in Core-collapse supernova Heavy-element nucleosynthesis: The r-process Summary r-process Astrophysical sites
Core-collapse supernova Neutron star mergers Neutrino-winds from protoneutron Matter ejected ( 0.01 M ) ∼ stars. dynamically during merger. Aspherical explosions, Jets, Electromagnetic emission from Magnetorotational Supernova, ... radioactive decay of r-process nuclei [Winteler et al, ApJ 750, L22 (2012)] [KiloNova, Metzger, et al, MNRAS 406, 2650 (2010)] Recent observational claim of an r-process kilonova associated with GRB 130603B Electron capture in Core-collapse supernova Heavy-element nucleosynthesis: The r-process Summary Kilonova Observation
LETTER doi:10.1038/nature12505
A ‘kilonova’ associated with the short-duration c-ray burst GRB 130603B
N. R. Tanvir1, A. J. Levan2, A. S. Fruchter3, J. Hjorth4, R. A. Hounsell3, K. Wiersema1 & R. L. Tunnicliffe2
Time since GRB 130603B (d) N 1 10 0.6 m I μ 10–11 21 X-ray F606W F 22 F160W
23 –12 T 10 X-ray Dux (er 24
O5″ 25 g s –1 1.6 μm –13 10 cm AB magnitude 26 –2 N ) 27
N 28 F10–14
29
E 104 105 O106 Time since GRBOO 130603B (s) Direct observation of an r-process nucleosynthesis event?
Nbur Electron capture in Core-collapse supernova Heavy-element nucleosynthesis: The r-process Summary Sensitive to nuclear physics input
10−3
10−4
10−5
10−6 Abundance Solar r−process Abundances FRDM −7 WS3 10 HFB 21 DZ31 10−8 100 120 140 160 180 200 Mass Number Bauswein, Goriely, Janka, ApJ 773, 78 (2013) Joel Mendoza-Temis (PhD)
Strong sensitivity nuclear physics input: particularly masses and fission yields. Electron capture in Core-collapse supernova Heavy-element nucleosynthesis: The r-process Summary Beyond mean field calculations of nuclear masses
All global mass models assume a static nuclear shape. Moreover, the HFB Ca Isotopes wave functions break particle number 50 18 and angular momentum symmetries. 16 40 14 These effects can be accounted using 12 (MeV) 10 n 2
30 S 8 beyond mean field methods including 6 4 (MeV)
particle and angular momentum n HFB (D1S) 48 50 52 54 56
2 20 GCM (D1S)
S Mass Number A projection and configuration mixing CC 10 NN+3N (MBPT) using the Generator Coordinate Exp Method. 0 40 50 60 Additionally these methods allow for Mass Number A a complete description of all low energy spectroscopic properties. A. Akzhanov. T. Rodriguez, GMP, in preparation Electron capture in Core-collapse supernova Heavy-element nucleosynthesis: The r-process Summary Beyond mean field calculations of nuclear masses
Cd Isotopes All global mass models assume a static 0.4 nuclear shape. Moreover, the HFB 0.2 2
wave functions break particle number β 0
and angular momentum symmetries. HFB•D1S •0.2 FRDM
These effects can be accounted using •0.4 beyond mean field methods including particle and angular momentum 12 projection and configuration mixing 8 using the Generator Coordinate HFB•D1S (MeV)
n Exp 2
Method. S 5DCH•D1S 4 GCM•D1S Additionally these methods allow for FRDM
a complete description of all low 0
energy spectroscopic properties. 70 80 90 100 Neutron Number
A. Akzhanov. T. Rodriguez, GMP, in preparation Electron capture in Core-collapse supernova Heavy-element nucleosynthesis: The r-process Summary Role N 90 nuclei (Te isotopes) ∼ 10 FRDM DZ31 8 WS3 HFB 21 AME 2012 6 (MeV) n 4 S
2 Te (Z=52) Isotopes 0 70 75 80 85 90 95 100 105 110 Neutron Number Experimental masses: Hakala et al, PRL 109, 032501 (2012) (JYFLTRAP) Van Schelt, et al, PRC 85, 045805 (2012) (Canadian penning trap) Electron capture in Core-collapse supernova Heavy-element nucleosynthesis: The r-process Summary Role N 90 nuclei (Cd isotopes) ∼
8 FRDM DZ31 WS3 6 HFB 21 AME 2012 4 Cd (Z=48) Isotopes (MeV) n S 2
0
70 75 80 85 90 95 100 105 110 115 120 Neutron number Electron capture in Core-collapse supernova Heavy-element nucleosynthesis: The r-process Summary Impact r-process abundances (NS Mergers)
10−3
10−4
10−5
10−6 Abundance Solar r−process Abundances FRDM −7 WS3 10 HFB 21 DZ31 10−8 100 120 140 160 180 200 Mass Number
Masses around N = 90 determine the mass flow from second to third r-process peaks. Joel Mendoza-Temis (PhD) Electron capture in Core-collapse supernova Heavy-element nucleosynthesis: The r-process Summary Summary
Shell-model calculations of iron-group electron capture rates have been validated by charge-exchange data. New experimental evidence of collectivity around N 40 can ∼ potentially influence electron capture rates. Neutrino-winds simulations based on an EoS that is consistent with constrains on the symmetry energy produce elements between Zn and Mo, including 92Mo. No heavier elements are produced. Heavier r-process elements can be produced in neutron-star mergers. Beyond mean field models can provide an accurate description of nuclear masses for r-process nucleosynthesis. The collectivity of nuclei with Z . 50 and N 90 has a strong ∼ impact in r-process nucleosynthesis.