Colour Confinement and Deformed Baryons in Quantum Chromodynamics

The confinement of coloured entities in Quantum Chromodynamics (QCD) is traced to colour singletness of the observed entities. This is believed to arise from colour singlet state of quark-antiquark for mesons and a fully colour antisymmetric state for baryons. This demands a spherically symmetric baryon in the ground state. However it is pointed out that a deformed baryon in the ground state has been found to be extremely successful phenomenology. There are convincing experimental supports for a deformed nucleon as well. This means that something has been missed in the fundamental theory. In this paper this problem is traced to a new colour singlet state for baryons which has been missed hitherto and incorporation of which provides a consistent justification of a deformed baryon in the ground state. Interestingly this new colour singlet state is global in nature.Comment: 5 pages, 1 figur

Gravitational Perfect Fluid Collapse in Gauss-Bonnet Gravity

The Einstein Gauss-Bonnet theory of gravity is the low energy limit of heterotic super-symmetric string theory. This paper deals gravitational collapse of perfect fluid in Einstein Gauss-Bonnet gravity by considering the Lemaitre - Tolman - Bondi metric. For this purpose, the closed form of exact solution of equations of motion has been determined by using the conservation of stress-energy tensor and the condition of marginally bound shells. It has been investigated that the presence of Gauss-Bonnet coupling term $\alpha>0$ and pressure of the fluid modifies the structure and time formation of singularity. In this analysis singularity form earlier than horizon, so end state of the collapse is a naked singularity depending on the initial data. But this singularity is weak and timelike that goes against the investigation of general relativity.Comment: 16 pages, 3 Figures; some future research directions mentioned; to appear in European Physical Journal

Models of Anisotropic Self-Gravitating Source in Einstein-Gauss-Bonnet Gravity

In this paper, we have studied gravitational collapse and expansion of non-static anisotropic fluid in $5D$ Einstein Gauss-Bonnet gravity. For this purpose, the field equations have been modeled and evaluated for the given source and geometry. The two metric functions have been expressed in terms of parametric form of third metric function. We have examined the range of parameter $\beta$ (appearing in the form of metric functions) for which $\Theta$ the expansion scalar becomes positive/negative leads to expansion/collapse of the source. The trapped surface condition has been explored by using definition of Misner-Sharp mass and auxiliary solutions. The auxiliary solutions of the field equations involve a single function which generates two types of anisotropic solutions. Each solution can be represented in term of arbitrary function of time, this function has been chosen arbitrarily to fit the different astrophysical time profiles. The existing solutions forecast gravitational expansion and collapse depending on the choice of initial data. In this case, it has been investigated wall to wall collapse of spherical source. The dynamics of the spherical source has been observed graphically with the effects of Gauss-Bonnet coupling term $\alpha$ in the case of collapse and expansion. The energy conditions are satisfied for the specific values of parameters in the both solutions, this implies that the solutions are physically acceptable.Comment: 20 pages,16 Figures, Title Changed, Major revision included,accepted version to appear in Adv.High Energy Physic