$\rho \omega$--Mixing and the Pion Electromagnetic Form Factor in the Nambu--Jona-Lasinio Model

Abstract

The $\rho \omega$--mixing generated by the isospin breaking of the current quark masses $m_u\ne m_d$ is studied within the bosonized NJL model in the gradient expansion. The resulting effective meson lagrangian naturally incorperates vector meson dominance. By including pion loops an excellent description of both the pion electromagnetic form factor and of the ${\pi }^{+}{\pi }^{-}$ phase shifts in the vector--isovector channel is obtained. The $\rho \omega$--mixing can be treated in the static approximation but is absolutely necessary to reproduce the fine structure of the electromagnetic form factor, while the pion loops are necessary to obtain the correct energy dependence of the phase shifts.

11 LaTeX pages, 4 figures available upon request

References in corpus (4)

• The Momentum Dependence of the $\rho -\omega$ Mixing Amplitude in a Hadronic Model
• Constraints on the momentum dependence of rho-omega mixing
• The Off Shell $\rho$-$\omega$ Mixing in the QCD Sum Rules
• Charge symmetry breaking via rho-omega mixing from model quark-gluon dynamics

Cited by in corpus (9)

• Rho-omega mixing, vector meson dominance and the pion form-factor
• Analysis of rho-omega interference in the pion form-factor
• Pion Loop Contribution to Rho-Omega Mixing and Mass Splitting
• A new Perspective on the Scalar meson Puzzle, from Spontaneous Chiral Symmetry Breaking Beyond BCS
• Extracting the rho-omega mixing amplitude from the pion form-factor
• A New State Of Hadronic Matter At High Density
• Isospin Breaking and $\omega$->$\pi \pi$ Decay
• Vector Meson Mixing and Charge Symmetry Violation
• On extracting the rho-omega mixing amplitude from the pion form-factor