Berlin 2005 – wissenschaftliches Programm
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HK: Physik der Hadronen und Kerne
HK 19: Theorie
HK 19.4: Vortrag
Montag, 7. März 2005, 15:15–15:30, TU MA005
Some consistency conditions in effective field theory with vector mesons — •Matthias Schindler1, Dalibor Djukanovic1, Jambul Gegelia1,2, and Stefan Scherer1 — 1Institut für Kernphysik, Johannes Gutenberg-Universität, Mainz, Germany — 2High Energy Physics Institute, Tbilisi State University, Tbilisi, Georgia
Effective field theories (EFT) are non-renormalizable in the traditional sense. However, in a consistent EFT all ultraviolet divergences must be absorbable in the redefinition of fields, masses, and coupling constants. The renormalization procedure imposes consistency conditions among the parameters of the Lagrangian.
We first consider the effective Lagrangian describing the interaction among ρ mesons, pions, and nucleons. We perform a one-loop order analysis of the nucleon and ρ-meson self-energies as well as the ρρρ and ρ NN vertex functions. Both the universal coupling of the ρ meson as well as the KSRF value of the ρ-meson coupling constant turn out to be consequences of the self-consistency conditions [1].
Next we include the electromagnetic interactions in the EFT. From the construction as the most general Lagrangian the vector mesons have an arbitrary magnetic moment related to a free constant κ. We analyze self-energies as well as three-particle vertex diagrams at the one-loop level. Imposing the consistency conditions we find that the constant κ is equal to the electric charge, κ=e, and the ρ±−ρ0 mass ratio is given by M±/M0=√1−e2/g2, where g is the ρ meson coupling constant.
[1] D. Djukanovic, M. R. Schindler, J. Gegelia, G. Japaridze, and S. Scherer, Phys. Rev. Lett. 93, 122002 (2004).