We study QCD in 1 + 1 dimensions in the large Nc limit using light-front Hamiltonian perturbation theory in the 1/Nc expansion. We use this formalism to exactly compute hadronic transition matrix elements for arbitrary currents at leading order in 1/Nc, which we use to write the semileptonic differential decay rate of a heavy meson and its moments. We then compare with the results obtained usin...

Spontaneous CPT breaking arising in string theory has been suggested as a possible observable experimental signature in neutral-meson systems. We provide a theoretical framework for the treatment of lowenergy effects of spontaneous CPT violation and the attendant partial Lorentz breaking. The analysis is within the context of conventional relativistic quantum mechanics and quantum field theory ...

The main elements and methods of chiral perturbation theory, the effective field theory of the Standard Model below the scale of spontaneous chiral symmetry breaking, are summarized. Applications to the interactions of mesons and baryons at low energies are reviewed, with special emphasis on developments of the last three years. Among the topics covered are the strong, electromagnetic and semil...

An exposition is made of recent developments using techniques of unitary chiral perturbation theory, UχPT , which allows one to extend predictions using chiral Lagrangians to higher energies than ordinary chiral perturbation theory, including the region of low lying mesonic and baryonic resonances, some of which are dynamically generated in the approach. Results for meson meson scattering, pion...

The (σ, ω) model in mean-field approximation where the meson fields are treated classically, describes much of observed nuclear structure and has been employed to describe the nuclear equation of state up to the quark-gluon phase transition. The acceleration of the meson sources, for example, in relativistic heavy-ion collisions, should result in bremsstrahlung-like radiation of the meson field...

We consider the formulation of two dimensional QCD in terms of gauge invariant bilocal operators (string field) which satisfy aW∞ algebra. In analogy with our work on the c = 1 string field theory we derive an action and associated constraints for the bilocal field using the method of coadjoint orbits. The 1/N perturbation theory around a classical solution that corresponds to the filled Dirac ...

Relativistic Hamiltonians are defined as the sum of relativistic one-body kinetic energies, twoand many-body interactions and their boost corrections. We review the calculation of the boost correction of the two-body interaction from commutation relations of the Poincaré group and show that its important terms can be easily understood from classical relativistic mechanics. The boost corrections...

A simple relation between the effective parameters of chiral Lagrangians in medium as predicted by BR scaling and Landau Fermi liquid parameters is derived. This provides a link between an effective theory of QCD at mean-field level and many-body theory of nuclear matter. It connects in particular the scaling vector-meson mass probed by dileptons produced in heavy-ion collisions (e.g., CERES of...

In this note, we report on a remarkable and surprising interplay between the ω meson and the dilaton χ in the structure of a single skyrmion as well as in the phase structure of dense skyrmion matter which may have a potentially important consequence on the properties of compact stars. In our continuing effort to understand hadronic matter at high density, we have developed a unified field theo...

In this paper we present a detailed formulation for a recently proposed effective field theory to describe the nonperturbative QCD dynamics of heavy mesons. This effective theory incorporates with heavy quark symmetry (HQS) and the heavy quark effective theory (HQET). Heavy mesons in this theory are constructed as composite particles of a heavy quark bounded with the light degrees of freedom. T...