INFRARED BEHAVIOR OF THE ATTRACTIVE DI-QUARK CHANNEL IN THE QCD MODEL

We examine the behavior of the attractive di-quark (qq) channel in the infrared region. Conventionally it is considered that the qq channel does not cause the fermion condensation in spite of its attractive interaction, because the quark field is dynamically massive due to the quark–antiquark condensation and the decoupling dynamics is applied. In this paper, we are going to reconsider rigorously the infrared behavior of the qq channel with paying attention to the stability of the effective action. And it is revealed that the behavior is not naively decided by the decoupling dynamics.

A simple explanation of the nonappearance of physical gluons and quarks

We show that the nonappearance of gluons and quarks as physical particles is a rigorous and automatic result of the full, i.e., nonperturbative, nonabelian nature of the color interaction in quantum chromodynamics (QCD). This makes it, in general, impossible to describe the color field as a collection of elementary quanta (gluons). Neither can a quark be an elementary quantum of the quark field, as the color field of which it is the source is itself a source, making isolated noninteracting quarks, crucial for a physical particle interpretation, impossible. In geometrical language, the impossibility of quarks and gluons as physical elementary particles arises due to the fact that the color Yang–Mills space does not have a constant trivial curvature. In QCD, the particles "gluons" and "quarks" are merely artifacts of an approximation method (the perturbative expansion) and are simply absent in the exact theory. This also coincides with the empirical, experimental evidence. PACS Nos.: 12.38Aw, 03.70+k, 11.15-q

RADIATIVE DECAY OF HEAVY MESONS IN A RELATIVISTIC QUARK MODEL

Radiative decays of heavy vector mesons are considered in the lowest order in a field-theoretic quark model of composite hadrons. The translationally invariant hadron states required in such a calculation are described by constituent quark field operators satisfying equal time algebra and harmonic oscillator wave functions. The constituent quark field operators are Lorentz-boosted through a spin rotation to describe hadrons in motion. The model, like its earlier success in describing different hadronic phenomena, in the present investigation without any free parameters also obtains the radiative decay widths and transition moments in reasonable agreement with other theoretical calculations as well as experimental measurements.

EXCLUSIVE SEMILEPTONIC DECAYS OF D AND B-MESONS IN A RELATIVISTIC QUARK MODEL

The exclusive semileptonic decays like D0 and B0 mesons are studied in the framework of a relativistic field-theoretic quark model, where translationally invariant hadronic states are described by constituent quark field operators satisfying equal time algebra and a harmonic oscillator wave function. The present estimations to the relevant form factors and their q2 dependence, without any free parameters, show a reasonable agreement with the available experimental measurements and Heavy Quark Effective Theory (HQET) and other model calculations. Further, the calculated decay widths and their ratios, and the polarization ratios for decay processes also have a reasonable agreement with the available experiments and other model estimations.