Effective String Description of the Confining Flux Tube at Finite Temperature

In this review, after a general introduction to the effective string theory (EST) description of confinement in pure gauge theories, we discuss the behaviour of EST as the temperature is increased. We show that, as the deconfinement point is approached from below, several universal features of confining gauge theories, like the ratio Tc/σ0, the linear increase of the squared width of the flux tube with the interquark distance, or the temperature dependence of the interquark potential, can be accurately predicted by the effective string. Moreover, in the vicinity of the deconfinement point the EST behaviour turns out to be in good agreement with what was predicted by conformal invariance or by dimensional reduction, thus further supporting the validity of an EST approach to confinement.

Study on Abelian dominance of Interquark potential in SU (3) Lattice QCD using simulation Techniques

It is assumed that no free quark to be found in nature. This is known as the confinement problem, is an issue which has no analytic proof till yet. But lattice QCD Monte Carlo simulations have shown that for large distances the quark antiquark potential varies linearly with interquark distance and controlled by the string tension. In the present work we have revisited the study of interquark potentials and Abelianization of QCD in Maximally Abelian gauge in context of dual superconducting picture. We have also observed the perfect Abelian dominance of the string tension for various spatial size lattices.

Study on Abelian dominance of Interquark potential in SU (3) Lattice QCD using simulation Techniques

It is assumed that no free quark to be found in nature. This is known as the confinement problem, is an issue which has no analytic proof till yet. But lattice QCD Monte Carlo simulations have shown that for large distances the quark antiquark potential varies linearly with interquark distance and controlled by the string tension. In the present work we have revisited the study of interquark potentials and Abelianization of QCD in Maximally Abelian gauge in context of dual superconducting picture. We have also observed the perfect Abelian dominance of the string tension for various spatial size lattices.

Bethe-Salpeter wave functions of ηc(1S, 2S) and ψ(1S, 2S) states: local-potential description of the charmonium system revisited

The quark potential models with an energy-independent central potential have been successful for understanding the conventional charmonium states especially below the open charm threshold. As one might consider, however, the interquark potential is in general energy-dependent, and its tendency gets stronger in higher lying states. Confirmation of whether the interquark potential is energy-independent is also important to verify the validity of the quark potential models. In this talk, we examine the energy dependence of the charmonium potential, which can be determined from the Bethe-Salpeter (BS) amplitudes of cc̅ mesons in lattice QCD.We first calculate the BS amplitudes of radially excited charmonium states, the ηc(2S) and ψ(2S) states, using the variational method and then determine both the quark kinetic mass and the charmonium potential within the HAL QCD method. Through a direct comparison of charmonium potentials determined from both the 1S and 2S states, we confirm that neither the central nor spin-spin potential shows visible energy dependence at least up to 2S state.

Studies on Polyakov and Nambu–Goto random surface path integrals on QCD(SU(∞)): Interquark potential and phenomenological scattering amplitudes

We present new path integral studies on the Polyakov noncritical and Nambu–Goto critical string theories and their applications to [Formula: see text] interquark potential. We also evaluate the long distance asymptotic behavior of the interquark potential on the Nambu–Goto string theory with an extrinsic term in Polyakov’s string at [Formula: see text]. We also propose an alternative and a new view to covariant Polyakov’s string path integral with a fourth-order two-dimensional quantum gravity, is an effective stringy description for [Formula: see text] at the deep infrared region.