Related papers: The effective QCD running coupling constant and a …
We consider a phenomenologycal parametrization of the QCD running coupling which arises from the dispersion relation respecting the holomorphic properties of the physical QCD observables in the complex momentum plane. The parameters are…
We consider a simple model of large-Nc QCD defined by a spectrum consisting of an infinite set of equally spaced zero-width vector resonances. This model is an excellent theoretical laboratory for investigating certain approximation schemes…
We formulate the concept of dominant interaction Hamiltonians to obtain an integrable approximation to the dynamics of an electron exposed to a strong laser field and an atomic potential leading to high harmonic generation. The concept…
Effective field theories of the strong interactions based on the approximate chiral symmetry of QCD provide a model-independent approach to low-energy hadron physics. We give a brief introduction to mesonic and baryonic chiral perturbation…
QCD is the accepted (that is, the effective) theory of the strong interaction; studies at colliders are no longer designed to establish this. Such studies can now be divided into two categories. The first involves the identification of…
We compute the microscopic spectrum of the QCD Dirac operator in the presence of dynamical fermions in the framework of random-matrix theory for the chiral Gaussian unitary ensemble. We obtain results for the microscopic spectral…
We investigate the spectral properties of a random matrix model, which in the large $N$ limit, embodies the essentials of the QCD partition function at low energy. The exact spectral density and its pair correlation function are derived for…
We discuss the quarkonium hybrid spectrum from the perspective of nonrelativistic effective field theories combined with lattice QCD.
I discuss the construction of the effective action for QCD suitable for the description of high-energy and small momentum transfer diffractive processes.
The variational approach to QCD in Coulomb gauge developed previously by the T\"ubingen group is improved by enlarging the space of quark trial vacuum wave functionals through a new Dirac structure in the quark-gluon coupling. Our ansatz…
Electromagnetic effects play an important role in many phenomena such as isospin-symmetry breaking in the hadron spectrum and the hadronic contributions to g-2. We have generalized the MILC QCD code to include the electromagnetic field. In…
We present an effective field theory model for QCD at finite temperature with quarks. We discuss the mean field theory, the fixing of parameters, and a prediction for the curvature of the critical line. We proceed to write down a pionic…
We derive a (Wilsonian) effective field theory of QCD at finite density by integrating out the states in the Dirac sea when the chemical potential $\mu\gg\Lambda_{\rm QCD}$. The quark-gluon coupling is effectively (1+1)-dimensional and the…
We present our final results of the charmonium spectrum in quenched QCD on anisotropic lattices. Simulations are made with the plaquette gauge action and a tadpole improved clover quark action employing $\xi = a_s/a_t = 3$. We calculate the…
Since physics of the dark sector components of the Universe is not yet well-understood, the phenomenological studies of non-minimal interaction in the dark sector could possibly pave the way to theoretical and experimental progress in this…
A model which combines the perturbative behavior of QCD with low energy phenomenology in a unified framework is developed. This is achieved by applying a similarity transformation to the QCD Hamiltonian which removes interactions between…
Nonrelativistic quark models of charmonia are tested by comparison of theoretical charmonium decay constants, form factors, and $\gamma\gamma$ widths with experiment and lattice gauge computations. The importance of relativistic effects, a…
The Dirac oscillators are shown to be an excellent expansion basis for solutions of the Dirac equation by $R$-matrix techniques. The combination of the Dirac oscillator and the $R$-matrix approach provides a convenient formalism for…
Point-to-point correlation functions of hadron currents in the QCD vacuum are calculated on a lattice and analyzed using dispersion relations, providing physical information down to small spatial separations. Qualitative agreement with…
Through a holographic model of QCD, we present a phenomenological approach to study the running of the strong coupling constant $\alpha_s$ in both non-perturbative and perturbative regimes. The renormalization of the metric tensor, driven…