The role of the hadron-quark phase transition in core-collapse supernovae

Abstract

The hadron-quark phase transition in quantum chromodyanmics has been suggested as an alternative explosion mechanism for core-collapse supernovae. We study the impact of three different hadron-quark equations of state (EoS) with first-order (DD2F_SF, STOS-B145) and second-order (CMF) phase transitions on supernova dynamics by performing 97 simulations for solar- and zero-metallicity progenitors in the range of $14\texttt {-}100\, \text{M}_\odot$. We find explosions only for two low-compactness models (14M⊙ and 16 M⊙) with the DD2F_SF EoS, both with low explosion energies of $\mathord {\sim }10^{50}\, \mathrm{erg}$. These weak explosions are characterised by a neutrino signal with several mini-bursts in the explosion phase due to complex reverse shock dynamics, in addition to the typical second neutrino burst for phase-transition driven explosions. The nucleosynthesis shows significant overproduction of nuclei such as 90Zr for the 14 M⊙ zero-metallicity model and 94Zr for the 16 M⊙ solar-metallicity model, but the overproduction factors are not large enough to place constraints on the occurrence of such explosions. Several other low-compactness models using the DD2F_SF EoS and two high-compactness models using the STOS EoS end up as failed explosions and emit a second neutrino burst. For the CMF EoS, the phase transition never leads to a second bounce and explosion. For all three EoS, inverted convection occurs deep in the core of the proto-compact star due to anomalous behaviour of thermodynamic derivatives in the mixed phase, which heats the core to entropies up to 4kB/baryon and may have a distinctive gravitational wave signature, also for a second-order phase transition.

Hybrid Isentropic Twin Stars

“…This corresponds to an enthalpic transition [7], supporting the conjecture that the appearance of thermal twins is linked to this transition (see Ref. [8] for details). For s/n B > 2, the jump is reversed.…”

Gravitational Waves from a Core g-Mode in Supernovae as Probes of the High-Density Equation of State

“…The CMF EoS has a ground state density (for symmetric matter) n sat = 0.16 fm −3 , binding energy per baryon E 0 /B = −15.2 MeV, asymmetry energy S 0 = 31.9 MeV, incompressibility K 0 = 267 MeV, and a maximum Tolman-Oppenheimer-Volkoff mass M max TOV = 2.10 M [43]. This EoS has recently been studied in the context of neutron star merger and 1D CCSN simulations [49,50]. The second EoS, used for runs z35:SFHx and z85:SFHx, is the purely hadronic relativistic meanfield SFHx model [42].…”

“…The lower 2 g 1 -mode frequency in the CMF models is rather connected to lower peaks of the Brunt-Väisälä frequency at the inner boundary of the PNS convection zone at densities below 2×ρ 0 (colored solid lines in Figure 3). At late times the buoyancy barrier at the bottom of the PNS convective zone disappears almost entirely, and the entropy profiles show overshooting into the core as favourable conditions for "inverted convection" to develop [50].…”

Constraining the Onset Density for the QCD Phase Transition with the Neutrino Signal from Core-collapse Supernovae

“…One observable feature that all these SN simulations have in common is the release of a second millisecond neutrino burst (see also Zha et al 2020;Jakobus et al 2022;Lin et al 2024) associated with the propagation of the second shock across the neutrinospheres, with a certain delay after the ν e bounce burst. Unlike the latter, the second neutrino burst is dominated by electron antineutrinos, which have the largest detection prospects within the current generation of water Cherenkov detectors through the inverse beta decay.…”