Related papers: On the $N_c$-insensitivity of QCD$_{2A}$
We discuss the non-factorizable terms in color suppressed (Class II) decays. Our emphasis is on the non-perturbative soft gluon exchange mechanism, which has been previously found to be responsible for the rule of discarding $ 1/N_{c} $ in…
$SU(N_c)$ lattice gauge theories with $N_f$ flavors of massless staggered fermions are considered at high quark chemical potential $\mu$ and any temperature $T$. In the strong coupling regime (sufficiently small $\beta$) they have been…
Quantum chromodynamics (QCD) with a general number of colors, $\Nc$, provides a powerful theoretical laboratory to explore the dynamics of non-Abelian gauge theories. Although $\Nc =3$ does not look a large number, the $1/\Nc$ expansion…
The light-front quantization of gauge theories such as QCD in light-cone gauge provides a frame-independent wavefunction representation of relativistic bound states, simple forms for current matrix elements, explicit unitarity, and a…
We briefly review the effective theory that describes the low energy properties of QCD with three light quarks and a large number of colours, N_c, and then discuss the mechanisms that forbid the Kaplan-Manohar transformation in this…
We analyze the Hamiltonian of the compactified D=11 supermembrane with non-trivial central charge in terms of the matrix model constructed recently by some of the authors. Our main result provides a rigorous proof that the quantum…
We introduce a $N_c\times N_c$ matrix model with $\mathcal{N}=2$ supersymmetries and show its relation to the topological rigid string and the topological YM$_2$. This allows to connect the latter two theories directly. Moreover the…
We consider unitary SQCD, a three-dimensional $\mathcal{N}=2$ supersymmetric Chern-Simons-matter theory consisting of one $U(N_c)_{k, k+l N_c}$ vector multiplet coupled to $n_f$ fundamental and $n_a$ antifundamental chiral multiplets, where…
The structure of the hadron spectrum is discussed in connection with the main phenomena of nonperturbative QCD: confinement and chiral symmetry breaking (CSB). For the higher part of the spectrum ($M \ge 2 GeV$) spin and chiral effects are…
It is shown that the matrix models which give non-perturbative definitions of string and M theory may be interpreted as non-local hidden variables theories in which the quantum observables are the eigenvalues of the matrices while their…
We study three dimensional N=2 supersymmetric QCD theories with O(N_c) gauge groups and with N_f chiral multiplets in the vector representation. We argue that for N_f < N_c-2 there is a runaway potential on the moduli space and no vacuum.…
The low energy effective actions of the $N=2$ SUSY $SU(N_c)$ QCD are considered at the symmetric point on the moduli space. The classes of such theories have similar spectral curves. This fact allows us to show that all these models have…
We consider the $N_c\to\infty$ limit of QCD using a toy model in which instantons exchange color-singlet scalar fields which do not self-interact. Our main observation is that collective attraction leads the formation of large clusters…
It is well-known that non-commutative (NC) field theories at theta = infinity are ``equivalent'' to large N matrix field theories to all orders in perturbation theory, due to the dominance of planar diagrams. By formulating a NC field…
We show how to obtain information about the states of an effective field theory in terms of the underlying fundamental theory. In particular we analyze the spectroscopic nature of meson resonances from the meson-meson scattering amplitudes…
We study QCD in 1+1 dimensions in the large $N_c$ limit using light-front Hamiltonian perturbation theory in the $1/N_c$ expansion. We use this formalism to exactly compute hadronic transition matrix elements for arbitrary currents at…
We develop a new systematic approach to quantum field theory that is designed to lead to physical states that rapidly converge in an expansion in free-particle Fock-space sectors. To make this possible, we use light-front field theory to…
The paper presents the representation of quantum field theory without introduction of infinity bare masses and coupling constants of fermions. Counter-terms, compensating for divergent quantities in self-energy diagrams of fermions and…
Analysis of the covariant theta-exact noncommutative (NC) gauge field theory (GFT), inspired by high energy cosmic rays experiments, is performed in the framework of the inelastic neutrino-nucleon scatterings. Next we have have found…
We investigate the large Nc limit of pure N=2 supersymmetric gauge theory with gauge group SU(Nc) by using the exact low energy effective action. Typical one-complex dimensional sections of the moduli space parametrized by a global complex…