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The Pion Form Factor Within the Hidden Local Symmetry Model

We analyze a pion form factor formulation which fulfills the Analyticity requirement within the Hidden Local Symmetry (HLS) Model. We show that it implies an $s$--dependent dressing of the $\rho-\gamma$ VMD coupling and an account of several coupled channels. The corresponding function $F_\pi(s)$ pr...

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Detalles Bibliográficos
Autores principales: Benayoun, Maurice, David, P., DelBuono, L., Leruste, P., O'Connell, Heath Bland
Lenguaje:eng
Publicado: 2003
Materias:
Acceso en línea:https://dx.doi.org/10.1140/epjc/s2003-01234-1
http://cds.cern.ch/record/600135
Descripción
Sumario:We analyze a pion form factor formulation which fulfills the Analyticity requirement within the Hidden Local Symmetry (HLS) Model. We show that it implies an $s$--dependent dressing of the $\rho-\gamma$ VMD coupling and an account of several coupled channels. The corresponding function $F_\pi(s)$ provides nice fits of the pion form factor data from $s=-0.25$ to $s=1$ GeV$^2$. It is shown that the coupling to $K \bar{K}$ has little effects, while $\omg \pi^0$ improves significantly the fit quality below the $\phi$ mass. All parameters, except for the subtraction polynomial coefficients are fixed from the rest of the HLS phenomenology. The fits show consistency with the expected behaviour of $F_\pi(s)$ at $s=0$ up to ${\cal O} (s^2)$ and with the phase shift data on $\delta_1^1(s)$ from threshold to somewhat above the $\phi$ mass. The $\omg$ sector is also examined in relation with recent data from CMD--2.