η in the nuclear medium within a chiral unitary approach Abstract The self-energy of an η meson in the nuclear medium is calculated in a chiral unitary approach. A coupled channel Bethe-Salpeter equation is solved to obtain the effective η-N interaction in the medium. The base model reproduces well the free space π-N elastic and inelastic scattering at the η-N threshold or N * (1535) region. Th...

Independent of assumptions about the form of the quark-antiquark scattering kernel we derive the explicit relation between the pion Bethe-Salpeter amplitude, Γπ, and the quark propagator in the chiral limit; Γπ necessarily involves a non-negligible γ5γ · P term (P is the pion four-momentum). We also obtain exact expressions for the pion decay constant, fπ, and mass, both of which depend on Γπ; ...

The self-consistent Green’s function method within the ladder approximation provides a microscopic description of correlated nuclear systems which properly treats the nucleon-nucleon correlations induced by the short-range and tensor components present in any realistic interaction. These correlations produce a sizable depletion of low momenta below the Fermi surface as well as the occupation of...

By solving the gap equation in the quenched, ladder approximation for an Abelian gauge model with Yukawa interaction in the presence of a constant magnetic field, we show that the Yukawa interactions enhance the dynamical generation of fermion mass. The theory is then studied at finite temperature, where we prove that the critical magnetic field, required for the mass generation to be important...

We bootstrap the all-loop dynamic S-matrix for the homogeneous psu(1, 1|2)2 spinchain believed to correspond to the discretization of the massive modes of string theory on AdS3 × S3 × T 4. The S-matrix is the tensor product of two copies of the su(1|1)2 invariant S-matrix constructed recently for the d(2, 1;α)2 chain, and depends on two antisymmetric dressing phases. We write down the crossing ...

The relativistic flux tube model is an effective description of confined quarks and gluons derived from QCD. It is not a potential approach since the confining interaction is carried by the flux tube, a Nambu-Goto string. We first show that the relativistic flux tube model can be applied to glueballs seen as bound states of transverse constituent gluons. After a comparison of that approach to u...

Abstract: The calculation of the magnetic moment of the deuteron in the framework of the Bethe–Salpeter approach is performed. The relativistic corrections are calculated analytically and estimated numerically. It is shown that the main contributions are due to partial waves with positive energies and P–waves. A comparison with the non-relativistic schemes of calculations including mesonic exch...

Using a previously established effective Lagrangian model we describe anti-kaon induced reactions on the nucleon. The dominantly contributing channels in the cm-energy region from threshold up to 1.72 GeV are included (KN , πΣ, πΛ). We solve the Bethe-Salpeter equation in an unitary K-matrix approximation .

The Bethe-Salpeter equation (BSE) for bound states in scalar theories is reformulated and solved in terms of a generalized spectral representation directly in Minkowski space. This differs from the conventional approach, where the BSE is solved in Euclidean space after a Wick rotation. For all but the lowest-order (i.e., ladder) approximation to the scattering kernel, the naive Wick rotation is...

A confining, Goldstone theorem preserving, separable Ansatz for the ladder kernel of the two-body Bethe-Salpeter equation is constructed from phenomenologically efficacious u, d and s dressed-quark propagators. The simplicity of the approach is its merit. It provides a good description of the ground-state isovector-pseudoscalar, vector and axial-vector meson spectrum; facilitates an exploration...