The Study Of Strange Quark Matter In A Strong Magnetic Field

The hypothesis of quark matter which is always constituted by quarks can not only reasonably describe the nature of microcosmic particles, but also has a prediction of complicated phase diagram. Due to the special properties of strange quark, strange quark matter (SQM) maybe has a stronger stability than usual quark matter. With an additional effective bag function added in the thermodynamic potential density of strange quark matter, we investigated based on the quasiparticle model the properties of strange quark matter at finite densities in the presence of strong magnetic field and derive new thermodynamic quantities in the quasiparticle description by the thermodynamic self-consistency. The effective bag function in strong magnetic field is obtained by the thermodynamic relation between bag function and thermodynamic potential density. It behaves with the density and the magnetic field. It’s important to note that the influence from strong magnetic field to strange quark matter contains both magnetized strange quark matter itself and magnetic field. The usual coupling constant and the running coupling constant, respectively, are both used to investigate the stability of strange quark matter in order to show the property of the asymptotic freedom of QCD. The magnetic field has an effect on the stability of strange quark matter and, especially, has a critical value of the order1017Gauss which is affected by the QCD scale parameter A. Strange quark matter will shows stronger stability as the strength of magnetic field is weaker than this critical field. However, as the QCD scale parameter A increasing over a value about126MeV, the effective bag function is not a monotonic function depending on density any more and has a maximum around0.3-0.4fm-3. Consequently, for the strange quark matter in the presence of strong magnetic field, we discuss not only about the effects on the stiffness of the equation of state from the magnetic field and QCD scale parameter A, but also investigate the mass-radius relation of magnetized quark stars and the possible maximum mass of strange quark stars.