scholarly journals QCD phase transition drives supernova explosion of a very massive star

2021 ◽  
Vol 57 (9) ◽  
Author(s):  
Tobias Fischer
Keyword(s):  
Phase Transition ◽  
Massive Star ◽  
Main Sequence ◽  
Supernova Explosion ◽  
Gluon Plasma ◽  
First Order Phase Transition ◽  
Solar Metallicity ◽  
Low Metallicity ◽  
First Order Phase

AbstractThe nature of core-collapse supernova (SN) explosions is yet incompletely understood. The present article revisits the scenario in which the release of latent heat due to a first-order phase transition, from normal nuclear matter to the quark–gluon plasma, liberates the necessary energy to explain the observed SN explosions. Here, the role of the metallicity of the stellar progenitor is investigated, comparing a solar metallicity and a low-metallicity case, both having a zero-age main sequence (ZAMS) mass of 75 M$$_\odot $$ ⊙ . It is found that low-metallicity models belong exclusively to the failed SN branch, featuring the formation of black holes without explosions. It excludes this class of massive star explosions as possible site for the nucleosynthesis of heavy elements at extremely low metallicity, usually associated with the early universe.

Coupling between order parameter and compositional fluctuations in the irradiation induced monoclinic to tetragonal phase transition in pure zirconia.

2003 ◽  
Vol 792 ◽  
Author(s):  
D Simeone ◽  
G Baldinozzi ◽  
D. Gosset ◽  
M. Dutheil
Keyword(s):  
Phase Transition ◽  
Tetragonal Phase ◽  
First Order ◽  
Nuclear Plants ◽  
First Order Phase Transition ◽  
Pure Zirconia ◽  
The Stability ◽  
First Order Phase ◽  
Tetragonal Phase Transition

ABSTRACTZirconia, oxidation product of Zircaloy cladding elements of nuclear plants, exhibits an unusual behaviour under irradiation. Impinging ions and neutrons induce a monoclinic to tetragonal phase transition at room temperature in this solid. To understand this modification of the positions of the stability lines in such a solid under irradiation, we have studied the monoclinic to tetragonal first order phase transition versus temperature in pure micrometric and nanometric zirconia samples. From these works, it was possible to understand the behaviour of this material under irradiation pointing out the key role of defects induced irradiation on its phase diagram.

scholarly journals Gravitational waves from dark Yang-Mills sectors

2021 ◽  
Vol 2021 (5) ◽  
Author(s):  
James Halverson ◽  
Cody Long ◽  
Anindita Maiti ◽  
Brent Nelson ◽  
Gustavo Salinas
Keyword(s):  
Phase Transition ◽  
Gravitational Waves ◽  
Gluon Plasma ◽  
Dark Sector ◽  
Gauge Groups ◽  
Yang Mills ◽  
First Order ◽  
First Order Phase Transition ◽  
First Order Phase ◽  
The Universe

Abstract Dark Yang-Mills sectors, which are ubiquitous in the string landscape, may be reheated above their critical temperature and subsequently go through a confining first-order phase transition that produces stochastic gravitational waves in the early universe. Taking into account constraints from lattice and from Yang-Mills (center and Weyl) symmetries, we use a phenomenological model to construct an effective potential of the semi quark-gluon plasma phase, from which we compute the gravitational wave signal produced during confinement for numerous gauge groups. The signal is maximized when the dark sector dominates the energy density of the universe at the time of the phase transition. In that case, we find that it is within reach of the next-to-next generation of experiments (BBO, DECIGO) for a range of dark confinement scales near the weak scale.

scholarly journals Gravitational wave signals of dark matter freeze-out

2021 ◽  
Vol 2021 (2) ◽  
Author(s):  
Danny Marfatia ◽  
Po-Yan Tseng
Keyword(s):  
Phase Transition ◽  
Dark Matter ◽  
Gravitational Waves ◽  
Order Phase Transition ◽  
First Order ◽  
Stochastic Background ◽  
First Order Phase Transition ◽  
Relic Abundance ◽  
First Order Phase ◽  
Freeze Out

Abstract We study the stochastic background of gravitational waves which accompany the sudden freeze-out of dark matter triggered by a cosmological first order phase transition that endows dark matter with mass. We consider models that produce the measured dark matter relic abundance via (1) bubble filtering, and (2) inflation and reheating, and show that gravitational waves from these mechanisms are detectable at future interferometers.

scholarly journals Dark Matter production from relativistic bubble walls

2021 ◽  
Vol 2021 (3) ◽  
Author(s):  
Aleksandr Azatov ◽  
Miguel Vanvlasselaer ◽  
Wen Yin
Keyword(s):  
Phase Transition ◽  
Dark Matter ◽  
Electroweak Phase Transition ◽  
First Order ◽  
Matter Production ◽  
First Order Phase Transition ◽  
Relic Abundance ◽  
Higgs Portal ◽  
First Order Phase ◽  
Gravitational Background

Abstract In this paper we present a novel mechanism for producing the observed Dark Matter (DM) relic abundance during the First Order Phase Transition (FOPT) in the early universe. We show that the bubble expansion with ultra-relativistic velocities can lead to the abundance of DM particles with masses much larger than the scale of the transition. We study this non-thermal production mechanism in the context of a generic phase transition and the electroweak phase transition. The application of the mechanism to the Higgs portal DM as well as the signal in the Stochastic Gravitational Background are discussed.

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