Phase diagrams of charged compact boson stars

Abstract

Compact boson stars, whose scalar field vanishes identically in the exterior region, arise in a theory involving a massless complex scalar field with a conical potential, when coupled to gravity. Their charged compact generalizations, obtained in the presence of a U(1) gauge field, exhibit further interesting features. On the one hand, charged compact boson shells can arise, whose scalar field vanishes also in the central region, while on the other hand, the domain of existence of charged compact boson stars exhibits bifurcation points. First 2D phase diagrams have been studied before. Here we extend these earlier studies to a larger range of the variables and study additional phase diagrams. We then extend these studies to obtain 3D phase diagrams and present these with a detailed discussion of their various regions with respect to the bifurcation points and argue, that there is an infinite series of such bifurcation points. Thus the theory is seen to contain rich physics in a particular domain of the phase diagrams. We also discuss the dependence of the fields on the dimensionless radial coordinate for some representative points of the phase trajectories in the phase diagrams of the theory.

Analysis of pseudoscalar and scalar D mesons and charmonium decay width in hot magnetized asymmetric nuclear matter

“…of protons and neutrons in heavy ion), strangeness (due to the presence of strange particles in the medium), temperature and density, recently it was found that in HICs, a strong magnetic field is also produced having field strength eB ∼ 2 − 15m 2 π (1m 2 π = 2.818 × 10 18 gauss) approximately [3][4][5]. Since then, physicists are trying to understand how the presence of magnetic field affects the I st and II nd order phase transitions [4,[6][7][8][9]. The time duration for which the magnetic field remains is a very debateable topic.…”

“…Many theories suggest that the magnetic field produced in HICs does not die immediately due to the interaction of itself with the medium. The primary magnetic field induces electric current in the matter and due to Lenz's law, a secondary magnetic field comes into picture which slows down the decay rate of the magnetic field [9][10][11][12][13][14][15]17]. These interactions increase the electric conductivity of the medium which further affects the relaxation time of the magnetic interaction and this phenomenon is called the chiral magnetic effect [4,[6][7][8].…”

“…The in-medium effects on open charm mesons are more than the quarkonium. This is due to the fact that the in-medium properties of D mesons depend upon light quark condensates which varies appreciably with the medium whereas, for charmonia (bottomonia), it depends on gluon condensates which do not change much with density [9,25]. It may also be noted that J/ψ suppression occurs not only due to QGP formation, but because of, density-dependent suppression, comover scattering [26] and nuclear dependence of D and B (for Υ suppression) mesons [27,28] too.…”

“…QCD Phase diagram is a graphical representation to account the different QCD regime's physics with different medium parameters. To study this diagram in hadron phase, several potential models are constructed on the basis of effective field theory by incorporating basic properties of QCD notably broken scale invariance and symmetry breaking [9,32]. Some of these models are: Walecka model [33], Nambu-Jona-Lasinio (NJL) model [34], chiral SU(3) model [9,32,[35][36][37], QCD sum rules [38][39][40][41][42][43], Quark-Meson Coupling (QMC) model [44][45][46][47][48][49], and coupled channel approach [50][51][52][53].…”

“…In addition to these articles, the effect of strong magnetic fields is also studied on the properties of ρ meson [71], B meson [72,73], charmonium [9,16,17,74] and bottomonium states [74,75]. A lot of work has also been done without taking the effect of magnetic field.…”