Lagrangian For Pseudoscalar Mesons Research Articles

DERIVATION OF ELECTROWEAK CHIRAL LAGRANGIAN FROM ONE FAMILY TECHNICOLOR MODEL

Based on previous studies deriving the chiral Lagrangian for pseudo scalar mesons from the first principle of QCD in the path integral formalism, we derive the electroweak chiral Lagrangian and dynamically compute all its coefficients from the one family technicolor model. The numerical results of the p4 order coefficients obtained in this paper are proportional to the technicolor number N TC and the technifermion number N TF , which agrees with the arguments in previous works, and which confirms the reliability of this dynamical computation.

ON QCD INVESTIGATIONS OF CHIRAL LAGRANGIAN

I review the present status of QCD investigations on chiral Lagrangian for pseudo scalar mesons.

Origin of four-dimensional vertices in qcd chiral Lagrangians

An effective 2 +4-dimensional Lagrangian for scalar and heavy pseudoscalar mesons is constructed by using the extended bosonization scheme of QCD. It is shown that the 4-dimensional vertices in the effective chiral Lagrangian for pseudoscalar mesons appear as a result of the reduction (expansion in 1/mπ)of the large masses of the π′ and σ mesons.

Nonlinear effective Lagrangian for pseudoscalar mesons in broken SU(3)×SU(3)

A symmetry-breaking term with derivative coupling $\mathrm{Tr}[({a}^{\ensuremath{'}}+{b}^{\ensuremath{'}}{\ensuremath{\lambda}}_{8}+{c}^{\ensuremath{'}}{\ensuremath{\lambda}}_{3})M{\ensuremath{\partial}}_{\ensuremath{\mu}}M{\ensuremath{\partial}}_{\ensuremath{\mu}}{M}^{\ifmmode\dagger\else\textdagger\fi{}}+\mathrm{H}.\mathrm{c}.]$ originating from the $(3,\overline{3})+(\overline{3},3)$ quark mass term is added to the minimal nonlinear meson Lagrangian for a unified description of SU(3)\ifmmode\times\else\texttimes\fi{}SU(3) breaking. These effects arise from a rescaling of the meson fields which gives automatically the ${K}_{l3}$ Callan-Treiman relation. SU(3) breaking for $\frac{{f}_{K}}{{f}_{\ensuremath{\pi}}}$ and $\frac{{f}_{{\ensuremath{\eta}}_{8}}}{{f}_{\ensuremath{\pi}}}$ is understood to come from the current quark mass ${m}_{s}$. Using this result, we find $\ensuremath{\Gamma}(\ensuremath{\eta}\ensuremath{\rightarrow}2\ensuremath{\gamma})=289\ifmmode\pm\else\textpm\fi{}20$ eV for ${\ensuremath{\theta}}_{P}=10.5\ifmmode^\circ\else\textdegree\fi{}$, in good agreement with the measured value 324\ifmmode\pm\else\textpm\fi{}50 eV. It is also shown that the $K\ensuremath{\rightarrow}3\ensuremath{\pi}$ slope parameters and relative decay rates are unaffected by this symmetry breaking.