Narrow Results

An attempt has been made to analyze the magnetic symmetry of the non-Abelian gauge theory associated with the strong interactions using the fibre bundle formulation. Utilizing the gauge field topology, the analysis of dual dynamics associated with the non-Abelian fields is shown to have important bearings on the nonperturbative hadronic effects like confinement of colored quarks and gluons inside hadrons. The state of dual superconductivity for the magnetically condensed vacuum has been analyzed to understand the bulk QCD magnetic properties by evaluating the current correlators in magnetic gauge in terms of the dielectric parameters. The dielectric behavior has been shown to lead to the p^-4 confining nature to the dual gluon propagators and to provide an effective macroscopic description of the complicated nonperturbative microscopic interactions of charged particles in dual QCD. The p^-4 behavior of dual gluon propagator has also been shown to confirm the linearly rising inter-quark confining potential with an explicit dual gluon mass dependency in dual QCD.

We study the flux tube structure of the nonperturbative QCD vacuum in terms of its dyonic excitations by using an infrared effective Lagrangian and show that the dyonic condensation of QCD vacuum has a close connection with the process of color confinement. Using the fiber bundle formulation of QCD, the magnetic symmetry condition is presented in a gauge covariant form and the gauge potential has been constructed in terms of the magnetic vectors on global sections. The dynamical breaking of the magnetic symmetry has been shown to lead the dyonic condensation of QCD vacuum in the infrared energy sector. Deriving the asymptotic solutions of the field equations in the dynamically broken phase, the dyonic flux tube structure of QCD vacuum is explored which has been shown to lead the confinement parameters in terms of the vector and scalar mass modes of the condensed vacuum. Evaluating the charge quantum numbers and energy associated with the dyonic flux tube solutions, the effect of electric excitation of monopole is analyzed using the Regge slope parameter (as an input parameter) and an enhancement in the dyonic pair correlations and the confining properties of QCD vacuum in its dyonically condensed mode has been demonstrated.

Color confinement is studied in dual version of SU(2) color gauge theory using its topological structure and the dynamical breaking of the magnetic symmetry which has been shown to effectively trigger the QCD monopole condensation in a dynamical way. The resulting flux tube structure of the QCD vacuum is explored which has been shown to lead to the perfect dual superconducting nature to the QCD vacuum in its dynamically broken phase. The analysis of the flux tube energy at different hadronic length scales has been shown to lead to the appearance of the strong confinement forces in QCD vacuum at large hadronic distances and an indication for the deconfinement phase at small scales. The analysis of the flux tube energy is then used to compute numerically the critical radius and the critical flux tube density of the phase transition from the flux tube phase to deconfined one inside hadrons. The numerical estimates are shown to be in fairly good agreement with the analytical values. The possible implications of these critical parameters on the formation of QGP as a result of the flux tubes fusion in intermediate energy regime are also discussed.

A Dual QCD formulation for $SU(3)$ color gauge has been developed in terms of dual gauge potentials, building on our previously published study for the $SU(2)$ case with zero bario-chemical potential [H. C. Chandola, G. Punetha and H. Dehnen, Nucl. Phys. A 945, 226 (2016).] and taking into account the local as well as topological structure of the color gauge group into its dynamics. For the purpose of examining the nonperturbative characteristics of QCD, the dynamical configuration of the resulting dual QCD vacuum and its flux tube configuration have been examined. The thermal behavior of the nonperturbative QCD vacuum has been investigated for exploring the dynamics of quark-hadron phase transition at finite chemical potential. Related thermodynamic quantities and equation of state (EoS) to characterize quark matter have also been discussed within the framework of dual QCD-based hadronic bag which guarantees the critical parameters and the associated critical points for quark-hadron phase transition. These thermodynamic quantities are expected to play important roles in understanding the order of quark-hadron phase transition and are likely to predict the features of a first-order quark-hadron phase transition for finite chemical potential. Moreover, we have investigated the bulk properties of quark matter by constructing the free energy change and the associated surface tension for quark-hadron phase transition. For consistency and compatibility check, we have also compared our results with state-of-the-art three-loop Hard Thermal Loop perturbative results and available lattice QCD results and in the process found reasonable agreements.