New aspects of the QCD phase transition in proto-neutron stars and - PowerPoint PPT Presentation

New aspects of the QCD phase transition in proto-neutron stars and core-collapse supernovae Matthias Hempel, Basel University Frankfurt, AstroCoffee, 24.11.2015

Motivation: core-collapse supernovae •how do massive stars explode? •which progenitors end as black holes, which as neutron stars? •what is their nucleosynthesis contribution, galactical chemical evolution? Matthias Hempel NASA/Chandra Frankfurt, 24.11.2015 2

Supernova explosion mechanism •presently favored: neutrino-driven mechanism (Colgate & White 1966) •explosion triggered by energy deposition of neutrinos in the infalling matter •requires multi-dimensional fluid instabilities: convection, turbulence, „standing accretion shock instability“, in general no explosions in 1D simulations •e.g. increases time of matter in gain region and thereby the neutrino heating SN1987A central proto- ν neutron star entropy ν ν standing accretion shock M. Liebendörfer Matthias Hempel Frankfurt, 24.11.2015 3

Example of a 3D supernova simulation •simulation by Kuo-Chuan Pan, Basel (arXiv:1505.02513) •15 M sun progenitor (Woosley et al. 2002) •HS(DD2) EOS, relativistic-mean field, nucleons, nuclei, electrons (MH and Schaffner-Bielich 2010) •hydrodynamics: FLASH (Lee 2003) •neutrino transport: IDSA (Liebendörfer et al. 2009) Matthias Hempel Frankfurt, 24.11.2015 4

2000 km 800 km 5

Open questions in core-collapse supernova theory •typically low explosion energies, cannot explain all supernovae •differences between 2D and 3D 0 1 . 2 1D 2D 1 . 0 3D � E expl [10 50 erg] 3D � 2D 0 . 8 56 Fe 0 . 6 min 0 . 4 0 . 2 Lentz et al. 2015, 15 M sun Pan et al. 2015 0 . 0 0 . 0 0 . 1 0 . 2 0 . 3 0 . 4 t pb [s] 2D, different progenitors and Melson et al. 2015, 9.6 M sun neutrino transport •all present 3D simulations still significantly underresolved? (e.g. Radice et al. arXiv:1510.05022) Matthias Hempel Frankfurt, 24.11.2015 6

Role of the EOS in core-collapse supernovae •different nuclear interactions/hadronic EOSs have only a moderate impact (Janka 2012, MH et al. 2012, Suwa 2013, Kuo-Chuan Pan et al. 2015, …) •no 2D or 3D simulations with non-nucleonic degrees of freedom yet (!) → what is the role of quark matter? Matthias Hempel Frankfurt, 24.11.2015 7

Core-collapse supernova explosions triggered by the QCD phase transition 8

Quark-hadron hybrid EOS for supernovae •2009/2011: Sagert, Pagliara, Schaffner-Bielich, MH •hybrid EOSs available as tables for various temperatures and asymmetries, suitable for core-collapse supernova simulations •hadronic phase: „STOS“, Shen, Toki, Oyamatsu and Sumiyoshi 1998, 2011 – n,p, α ,A,e – non-linear relativistic mean-field interactions (TM1) – Thomas-Fermi approximation for finite nuclei •quark phase: bag model p i ( m i , T, µ i , α s ) = p i ( m i , T, µ i , 0) – u,d,s (m s =100 MeV) � 7 i + µ 4 � 1 �� 60 T 4 π 2 50 α s 21 π + 2 α s – first-order corrections for strong 2 T 2 µ 2 i − 4 π 2 π interactions, α S (Farhi and Jaffe 1984) •phase transition: – global charge neutrality (Gibbs PT/non-congruent PT) Matthias Hempel Frankfurt, 24.11.2015 9

CCSN explosions by the QCD phase transition [Sagert, et al. PRL 2009] t pb = 240.5 ms t pb = 255.2 ms t pb = 255.4 ms t pb = 255.5 ms t pb = 256.3 ms t pb = 261.2 ms •phase transition induces collapse of the proto-neutron star •once pure quark matter is reached, collapse halts •formation of a second shock •higher temperatures, increased neutrino heating → positive velocities •shock merges with standing accretion shock •explosion Matthias Hempel Frankfurt, 24.11.2015 10

Neutrino signal •colored lines with phase Luminosity [10 53 erg/s] e Neutrino transition, black without e Antineutrino 1 •second neutrino burst due to 0.5 quark matter 0 •peak and height determine Time After Bounce [s] Luminosity [10 53 erg/s] µ / τ Neutrino density and strength of the phase µ / τ Antineutrino 1 transition •measurable with present day 0.5 neutrino detectors [DasGupta et al. 2009] 0 Time After Bounce [s] e Neutrino rms Energy [MeV] 30 e Antineutrino µ / τ Neutrinos 25 20 15 10 0 0.1 0.2 0.3 0.4 Time After Bounce [s] Matthias Hempel Frankfurt, 24.11.2015 11

Mass-radius relation of hybrid EOS and SN explosions • no explosions for TM1 sufficiently high B 1/4 =139 MeV, α s =0.7 PSR J1614-2230 2 maximum mass B 1/4 =145 MeV, α s =0.7 B 1/4 =155 MeV, α s =0.3 PSR J1903-0327 • weak phase Mass [solar mass] B 1/4 =162 MeV transition PSR B1913+16 1.5 B 1/4 =165 MeV • quark matter behaves similarly as 1 hadronic matter „masquerade“ • cf.: Fischer, 0.5 Blaschke, et al. 2012: PNJL hybrid EOS 0 8 10 12 14 16 18 Radius [km] explosions in spherical symmetry (T. Fischer et al. ApJS 2011) Matthias Hempel Frankfurt, 24.11.2015 12

Densities reached in the supernova Why does B145 not explode? → critical density too high Matthias Hempel Frankfurt, 24.11.2015 13

[Fischer, et al. Acta Phys. Neutrino signal for B139 hybrid EOS Polon. Suppl. 7 (2014)] 2.0 20 22 ν ν e µ / τ QB139 α S 0.7 21 ¯ ν ¯ e ν µ / τ STOS 20 19 19 1.5 L ν [10 52 erg s − 1 ] 〈 E ν 〉 rms [MeV] 18 18 ν e 17 16 1.0 17 15 14 16 13 ¯ ν e 0.5 / τ / ¯ 12 ν ν µ µ / τ 15 11 0 0.2 0.4 0.6 0.8 1.0 1.2 1.4 0 0.2 0.4 0.6 0.8 1.0 1.2 1.4 1.6 0 0.2 0.4 0.6 0.8 1.0 1.2 1.4 1.6 t − t bounce [s] t − t bounce [s] t − t bounce [s] •no second collapse, no explosion, no neutrino burst •only slight reconfiguration of proto-neutron star •moderate changes in neutrino signal •no smoking gun for quark matter in supernovae only few models tested, mechanism still possible for others? Matthias Hempel Frankfurt, 24.11.2015 14

Thermal properties of the hybrid EOS 15

QCD phase diagrams •fundamental question: phase diagram of strongly interacting matter •typically shown in T-µ, sometime also in T- ρ S. Rüster A. Ohnishi BNL Wikipedia TU Wien B. J. Schaefer K. Fukushima Matthias Hempel Frankfurt, 24.11.2015 16

Non-congruence of the nuclear liquid-gas and QCD phase transition [MH, V. Dexheimer, S. Schramm, I. Iosilevskiy, PRC 88 (2013)] symmetric matter •main topic: differences of phase transitions with single or multiple conserved charges •effects of isospin symmetry on phase diagrams •„congruent“ and „non-congruent“ phase transitions, commonly known as „Maxwell“ and „Gibbs“ asymmetric matter Matthias Hempel Frankfurt, 24.11.2015 17

Setup •liquid-gas phase transition of nuclear matter: non-linear relativistic mean-field model FSUgold [Todd-Rutel and Piekarewicz, PRL (2005)] •QCD phase transition: Chiral SU(3) model, includes quarks and hadrons as a chemical mixture of quasi-particle degrees of freedom [Dexheimer and Schramm, PRC81 (2010)] •neglect of all Coulomb interactions, “Coulomb-less“ approximation (cf. works by Gulminelli, Raduta, Typel, …) •solve for thermal, mechanical, and chemical equilibrium •in the following: symmetric nuclear matter, zero strangeness locally, no leptons Matthias Hempel Frankfurt, 24.11.2015 18

Phase diagram of symmetric baryonic matter — T-µ B chiral/deconfinement phase transition liquid-gas phase transition •different scales •similar shape, both phase transitions terminate in critical point Matthias Hempel Frankfurt, 24.11.2015 19 19

Is the QCD PT of liquid-gas type?

Phase diagram of symmetric baryonic matter — T-P chiral/deconfinement phase transition liquid-gas phase transition enthalpic entropic •opposite slope in T-P as fundamental difference see also: [Satarov, Dmitriev, Mishustin, PAN72 (2009)] [Bombaci et al., PLB680 (2009)] [Steinheimer, Randrup, Koch, PRC89 (2014)] [Iosilevskiy, arXiv:1403.8053] Matthias Hempel Frankfurt, 24.11.2015 21

The entropic QCD PT (dP/dT| PT <0) •Clausius-Clapeyron equation S I − S II � dP � = � 1 /n I B − 1 /n II dT � PT B •Steiner et al. PLB 468 (2000): � p 2 � F i + ( m ∗ i ) 2 i p F i S = T π 2 � i p F i •more degrees of freedom (color, strangeness) in the quark phase, and more relativistic •leads to high specific heat capacity and low temperatures • → QCD PT always entropic? •what about color-superconducting phases? (cf. Rüster et al. PRD73 (2006)) Matthias Hempel Frankfurt, 24.11.2015 22

General properties of entropic PTs (dP/dT| PT <0) •note: Clausius-Clapeyron equation only valid for a congruent (aka Maxwell) PT, i.e. where one has only one conserved charge •then one also has: � � = ∂ P dP � � � � ∂ T dT � � PT n B •using general thermodynamic relations: unusual sign of 2nd cross [Iosilevskiy, arXiv:1403.8053] derivatives, „abnormal thermodynamics“, e.g.: [Iosilevskiy, arXiv:1504.05850] � � ∂ P < 0 ⇔ ∂ T � � < 0 � � ∂ T ∂ n B T , GeV � � n B S 0.3 [Satarov et al. 2009] AA data thermal fit •dT/dn B | S <0 observed by many S / B authors, also well-known in HIC 5 30 0.2 300 • Steiner et al. PLB 2000 • Nakazato et al. APJ 2010 • Fischer et al. APJS 2011 0.1 • Yudin et al. Astron. L 2013 entropic • … 0 1 2 3 Matthias Hempel Frankfurt, 24.11.2015 , GeV 23 µ

Inverted convection in proto-hybrid stars [A.V. Yudin, MH, D.K. Nadyozhiny, T.L. Razinkova, arXiv:1507.04598, accepted by MNRAS] 24