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New possible quark-hadron mixed phase in protoneutron stars
G Pagliara1, M Hempel, J Schaffner-Bielich
1Institut für Theoretische Physik, Ruprecht-Karls-Universität, Philosophenweg 16, D-69120, Heidelberg, Germany.
Physical Review Letters
|November 13, 2009
Summary
A novel mixed phase with variable pressure may exist in protoneutron stars due to lepton number conservation. This phase impacts neutron star evolution and neutrino emissions.
Area of Science:
- Nuclear Physics
- Astrophysics
- High-Energy Physics
Background:
- The transition between hadronic and quark matter at high densities is a first-order phase transition, characterized by surface tension.
- In cold neutron stars, this leads to a constant-pressure mixed phase.
- However, hot and lepton-rich matter in protoneutron stars presents different conditions.
Purpose of the Study:
- To investigate the properties of the mixed phase in protoneutron stars, considering lepton number conservation during neutrino trapping.
- To determine if a non-constant pressure mixed phase can form in these extreme environments.
- To explore the implications of this new mixed phase on protoneutron star evolution and neutrino emission.
Main Methods:
- Analysis of global lepton number conservation during the neutrino trapping stage.
- Theoretical modeling of the mixed phase under protoneutron star conditions.
- Examination of the phase's behavior during deleptonization.
Main Results:
- A new mixed phase with non-constant pressure can emerge in protoneutron stars.
- This phase is transient, gradually disappearing as deleptonization progresses.
- The properties of this mixed phase are distinct from those found in cold neutron star matter.
Conclusions:
- The existence of a non-constant pressure mixed phase in protoneutron stars is theoretically supported.
- This phase could significantly influence the cooling and evolution of nascent neutron stars.
- Further study is warranted to understand its impact on observable neutrino signals.
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