Xia Zhou

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The deconfinement phase transition in the
interior of neutron stars
Huazhong Normal University

• Xia Zhou Xiao-ping Zheng

May 21, 2009 CSQCD?
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• Phase transition and energy release
• The thermal evolution of neutron stars
• Summary

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Phase transition and energy release
The total energy and baryon number densities for
the mixed phase
With the volume fraction, energy per baryon
The derivative of e with respect to ?
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Phase transition and energy release
Energy release per baryon with respect to total
baryon number
The energy release per baryon during phase
transition
From S to F, the total release energy can be
expressed as
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Phase transition and energy release

• Construct the hybrid stars
• Hadronic phase relativistic mean field theory
  (RMF)
• Quark phase MIT bag model
• Mixed phase baryon number conservation and
  global charge neutrality

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Phase transition and energy release
The baryon number density dependence of releasing
energy per converted baryon for different bag
constants
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Phase transition and energy release
The baryon number density dependence of releasing
energy per converted baryon for soft, moderate
and stiff hadronic matter equation of state
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Phase transition and energy release
Latent heat chemical balance
The absorbed energy per baryon during phase
transition
M. Stejner et.al ApJ, 6941019, 2009
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Phase transition and energy release
Heating luminosity of latent heat
it is less important and does not signi?cantly
change the thermal evolution ( M. Stejner et.al
ApJ, 6941019, 2009)
Heating luminosity of deconfinement heating
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• Hybrid stars neutron star with quark phase or
  mixed phase interiors. The mixed phase of
  hadronic and quark matter construct with Gibbs
  conditions
• The cooling equation
• Heating effect released dissipation energy
  during varying pressure first-order phase
  transition (deconfinement heating)

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Cooling curves of rotating hybrid star with
deconfinement heating
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Surface temperature due to rotochemical heating
and deconfinement heating in quasi-equilibrium
state as a function of stellar radius
O. Kargaltsev et.al ApJ, 602327,2004
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• The deconfinement dissipation would significantly
  influence the thermal evolution of neutron stars
• For the older pulsars with high thermal
  radiation, the deconfinement dissipation heating
  mechanism is more effect under the hybrid stars
  model
• We need more observational data