相关论文: Pion-mass dispersion relation in the baryon sector

We demonstrate how heavy mass methods, previously applied to chiral perturbation theory calculations involving the interactions of nucleons and pions, can be generalized to include interactions with the $\Delta(1232)$ in a systematic…

Data on pion polarizabilities obtained in different experiments are reviewed. The values of the dipole and quadrupole polarizabilities of the pi^0 and pi^{+-} mesons found are compared with predictions of dispersion sum rules (DSRs) and…

Chiral perturbation theory is the effective field theory of the strong interactions at low energies. We will give a short introduction to chiral perturbation theory for mesons and will discuss, as an example, the electromagnetic…

The chiral expansion of the one-loop corrections to baryon masses is examined in a generic meson-cloud model with meson-baryon form factors. For pion loops, the expansion is rapidly convergent and at fourth order in $m_\pi$ accurately…

I discuss the quark mass dependence of various baryon properties derived from chiral perturbation theory. Such representations can eventually be used as chiral extrapolation functions when lattice data at sufficiently small quark masses…

In the framework of chiral perturbation theory we investigate whether, in the presence of nucleons, a many-particle system may lower its energy density by changing its mesonic vacuum from a homogeneous to a spiral configuration. Numerical…

The relativistic six-quark equations are found in the framework of the dispersion relation technique. The charmed baryonia $B\bar B$ are constructed without the mixing of the quarks and antiquarks. The relativistic six-quark amplitudes of…

The behavior of the pion dispersion relation in a pion medium is strongly modified by the introduction of a finite chemical potential associated to the finite pion number density. Such behavior is particularly important during the hadronic…

Heavy baryon chiral perturbation theory is extended to include the effects of quenching. In this framework the leading nonanalytic dependence of the heavy baryon masses on the light quark masses is studied. The size of quenching effects is…

After contrasting the low energy effective theory for the baryon sector with one for the Goldstone sector, I use the example of pion nucleon scattering to discuss some of the progress and open issues in baryon chiral perturbation theory.

Many of the quantities of interest at the precision frontier in particle physics require a good understanding of the strong interaction at low energies. The present talk reviews the theoretical framework used in this context. In particular,…

Using the examples of pion-nucleon scattering and the nucleon mass we analyze the convergence of perturbative series in the framework of baryon chiral perturbation theory. For both cases we sum up sets of an infinite number of diagrams by…

We briefly review the generalized Skyrmion model for the baryon recently suggested by us. It takes into account the tower of vector and axial mesons as well as the chiral symmetry breaking. The generalized Skyrmion model provides the…

The effective masses of the neutral mesons in a hadronic medium and under an external magnetic field are evaluated as functions of the baryonic density and the field intensity. For this purpose the meson polarization is evaluated in the one…

We study the behavior of the pion dispersion relation in a pion medium at finite density and temperature, introducing a chemical potential to describe the finite pion number density. Such description is particularly important during the…

Heavy baryon chiral perturbation theory is briefly reviewed, paying particular attention to the role of the spin 3/2 delta resonances. The concept of resonance saturation for the baryonic sector is critically discussed. Starting from a…

In the framework of dispersion relation technique the relativistic three-quark equations including heavy quarks are found. The approximate solutions of the relativistic three-particles equations based on the extraction of leading…

The masses of the charmed baryons in the ${\bf 6}$ representation of $SU(3)$ obey an equal spacing rule at lowest order in $SU(3)$ breaking, ${\cal O}(m_s)$. We compute the corrections to this relation at order ${\cal O}(m_s^{3/2})$ arising…

To see whether heavy baryon and anti-baryon can form a bound state, the heavy baryonium, we study the interaction potential between them in terms of heavy baryon perturbation theory. The obtained potential is applied to calculate the heavy…

We calculate the pion-pion elastic scattering phase shifts for pion masses from the chiral limit to values of interest for lattice studies. At low energies, we use the standard Chiral Perturbation Theory expressions to one and two loops. In…