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 Systematic study measured GT strengths Electron capture in Core-collapse supernova A. L. Cole suffice. With increasing density, less sophisticated models like QRPARates may for iron-group nuclei are under control et al. , PRC 86 , 015809 (2012) Heavy-element nucleosynthesis: The r-process 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 Summary -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 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+ 0.0 11.163 s Intensities: Iγ per 100 2 3 parent decays −10 + → + 2 0 F 9 11 )] 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).