Compact strange stars with a medium dependence in gluons at finite temperature
1
Dept. of Physics, Presidency College, 86/1, College Street, Kolkata 700073, India e-mail: mnj2003@vsnl.net; kamal1@vsnl.com
2
Inter University Centre for Astronomy and Astrophysics (IUCAA), Post Bag # 4, Ganeshkhind, Pune 411007, India e-mail: sray@iucaa.ernet.in
Received:
30
June
2005
Accepted:
19
December
2005
Aims.The possible existence of strange stars in the universe will help in the understanding of various properties of quantum chromodynamics, like asymptotic freedom and chiral symmetry restoration, which is otherwise very difficult to prove in laboratory experiments.
Methods.Strange star properties were
calculated using large color approximation with built-in chiral
symmetry restoration. A relativistic Hartree Fock calculation was
performed using the Richardson potential as an interquark
interaction. This potential has the asymptotic freedom and a
confinement-deconfinement mechanism built into it and the present
calculation employs an application of this potential with modified
two scale parameters Λ and 
, to find a
new set of equations of state for strange quark matter. The linear
confinement string tension from lattice calculations is 350 MeV
and the Coulomb -like part has the parameter 100 MeV from deep
inelastic scattering experiments. We also consider the effect of
temperature, on gluon mass in a simple way, in addition to the
usual density dependence,
Results.We obtained a set of new equation of states for strange quark matter and also found that the transition temperature from hadronic matter to strange matter is at 80 MeV, close to the 100 MeV estimated in literature.
Conclusions.Formation of strange stars may be the only signal for formation of quark-gluon plasma with asymptotic freedom and chiral symmetry restoration and this may be observable through many processes – such as for example through delayed γ ray afterglow.
© ESO, 2006