Stellar core collapse with QCD phase transition

1. Stellar core collapse with QCD phase transition Ken’ichiro Nakazato （Tokyo University of Science） with K. Sumiyoshi（Numazu CT）and S. Yamada（Waseda U）, EOS project: T. Miyatsu （Soongsil U）and S. Yamamuro（TUS） Compact Stars in the QCD Phase Diagram IV @ Prerow, Sep. 27, 2014

2. Fates of massive stars • Stars with > 10Msolar make a gravitational col- lapse and, possibly, a supernova explosion. • Stars with > 25Msolar are thought to form a black hole （BH）. • Observations show 2 branches. • Hypernovae （Rapid rotation） • Faint or Failed Supernovae （Weak rotation） Normal SN Nomoto+ （2006）

3. Failed supernova neutrinos • Failed supernova progenitor makes bounce once and recollapse to the black hole. • In this process, temperature and density of central region gets a few times 10 MeV and a few times r 0 (saturation density of nuclear matter), and a lot of neutrinos are emitted. Proto-neutron star Massive star Black hole n n n n n Core Collapse Bounce Mass accretion

4. Motivation • Collapsing core would be enough hot and dense to undergo QCD transition. T heavy ion collision Quark Phase Early Universe ~150MeV Mixed Phase Hadronic Phase Black Hole Formation Supernova Stellar Collapse Compact stars r r0 0

5. Aims of this study Nakazato, Sumiyoshi and Yamada（2008a, 2010b, 2013b）. • We compute the dynamics and n emission for the black hole formation of 40Msolar（failed supernova） and supernova explosion of 15Msolarnon-rotating progenitor involving equation of state （EOS）with QCD transition. • General relativistic n radiation hydrodynamics in spherical symmetry （Sumiyoshi+ 2005）. • QCD transition: Shen EOS + MIT bag • We investigate the impacts on the dynamics and n signal.

6. Hydrodynamics & Neutrinos Yamada, Astrophys. J. 475（1997）, 720 Yamada et al., Astron. Astrophys. 344（1999）, 533 Sumiyoshi et al., Astrophys. J. 629（2005）, 922 Spherical, Fully GR Hydrodynamicsmetric：Misner-Sharp （1964）mesh：255 non uniform zones + Neutrino Transport （Boltzmann eq.） Species :ne,ne,nm（ = nt ） ,nm （ =nt ） Energy mesh :14 zones （0.9 – 350 MeV）　　 Reactions : e- + p ↔ n + ne, e+ + n ↔ p +ne, n + N ↔ n + N, n + e ↔ n + e, ne + A ↔ A’ + e-, n + A ↔ n + A, e- + e+↔ n +n, g* ↔ n +n, N + N’ ↔ N + N’ + n +n

7. Hadron-quark mixed EOS Nakazato et al., PRD 77（2008a）, 103006 • Shen EOS （1998） for Hadronic phase • MIT Bag model （Chodos et al. 1974） for Quark phase • Bag constant: B= 90, 150 and 250 MeV/fm3 • Gibbs conditions are satisfied in Mixed phase. • mn =mu + 2md,mp = 2mu + md • PH = PQ • b equilibrium （n trapping） is assumed inMixedand Quark phase. • md= ms,mp + me= mn + mn

8. Results for 40M☉ star Evolution of the central density. QCD transition fastens the BH formation. At the bounce, the case with B=90MeV/fm3has high density while others are similar. B = 90 MeV/fm3 B = 150 MeV/fm3 B = 250 MeV/fm3 Without Quarks （Shen）

9. Compositions（B = 250 MeV/fm3） Quark transition occurs at the very late phase and trigger the black hole formation. Nakazato et al., Astrophys. J. 721（2010b）, 1284 27 ms before BH formation 0.07 ms before BH formation at BH formation u d 1 1 n fraction s 0.5 0.5 p 0 0 1015 1015 density （g/cm3） AH 1013 1013 0 10 20 0 10 20 0 10 20 radius （km） radius （km） radius （km）

10. Compositions（B = 90 MeV/fm3） Quarks appear already at bounce. → the central density gets higher. Nakazato et al., Astron. Astrophys. 558（2013b）, A50 100 ms after bounce at BH formation at bounce u 1 1 n fraction s d 0.5 0.5 p 0 0 1015 1015 density （g/cm3） AH 1013 1013 0 10 20 0 10 20 0 10 20 radius （km） radius （km） radius （km）

11. Neutrino Signal nm/nm/nt/nt ne ne 250 250 2 2 150 150 luminosity（1053erg/s） 90 90 250 90 150 1 1 0 0 40 40 20 20 energy（MeV） 0 0 0.5 1 0 1 1.5 0 1 1.5 0 1.5 0.5 0.5 time （s） time （s） time （s） Apart from end points, there is no difference even for the model with B=90MeV/fm3. Neutrinos emitted from the outer region.

12. Fate of 15M☉ star For the cases withB=250,150MeV/fm3 , QCD transition does not occur at least 1 sec after the bounce. 　→ no SN explosion mass trajectory Phase diagram: B = 250 MeV/fm3 103 Quark 100 radius （km） Hadron Mix 10 Yℓ = 0.3 0 0.8 1 0.6 0.2 0.4 time after bounce （s） （Sumiyoshi et al. 2005） Central r and T of 1 s after bounce

13. 2nd bounce with B= 90 MeV/fm3 Confirming 2nd bounce and shock formation occurs for 15M☉ model. （Sagert+ 2009, Fischer+ 2011） s = 4.0kB Yℓ = 0.35 Mix → Quark 200.5 ms Hadron →Mix

14. Our recent workand ADVERTISEMENT

15. 木に竹を接ぐ（Ki ni také wo tsugu） Joining bamboo to a tree: disharmony Japanese proverb quark phase? tree bamboo hadron phase?

16. New EOS for neutron star matter Miyatsu, Yamamuro & Nakazato, ApJ 777（2013）, 4 • Chiral quark-meson coupling （CQMC） model • involving the coupling of scalar and vector fields to the quarks within nucleons • Relativistic Hartree-Fock PI: Dr. Tsuyoshi Miyatsu

17. New EOS for neutron star matter Miyatsu, Yamamuro & Nakazato, ApJ 777（2013）, 4 • Crust EOS with Thomas-Fermimodel • consistent with atomic mass data

18. New EOS for neutron star matter Miyatsu, Yamamuro & Nakazato, ApJ 777（2013）, 4 • Mmax = 1.95Msolar with hyperons

19. New EOS for neutron star matter Miyatsu, Yamamuro & Nakazato, ApJ 777（2013）, 4 • http://asphwww.ph.noda.tus.ac.jp/myn/ On-line EOS tables!!

20. Thank you for your attention

21. 一様核物質の状態方程式 ベクトル中間子のテンソル結合により、ハイペロンの生成が抑制される。 →　コア部分の状態方程式。 Chiral quark-meson coupling model ： Chiral quark-meson coupling model から s dependence を取り込む（非線形効果）

22. Coupling constant • Thomas-Fermi 計算により、原子核の質量・核子分布を計算し、Nとの結合定数を決める。 • gsN, gwN,grN : mass data • gsY : Hyperon potential • gwY, grY, fwB, frB : ESC model を gwN,grNで scale （Oyamatsu & Iida 2003）

23. Thomas-Fermi 計算 • バルクエネルギーに一様核物質 EOS を用いる。 • Chiral quark-meson coupling model • 結合エネルギーを最大化 n 幅 drの領域では一様 表面 エネルギー 中性子 陽子 クーロン エネルギー r

24. saturation パラメータ Li et al. arXiv:1211.1178 Esym (MeV) n0 = 0.155fm－3 w0 = -16.1 MeV K0 = 274 MeV Esym = 32.7 MeV L = 75.8 MeV