# The Pion Form Factor Within the Hidden Local Symmetry Model

Abstract : 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.
Document type :
Journal articles
Domain :

http://hal.in2p3.fr/in2p3-00184917
Contributor : Dominique Girod <>
Submitted on : Friday, November 2, 2007 - 6:42:23 PM
Last modification on : Friday, April 10, 2020 - 5:04:30 PM

### Citation

M. Benayoun, P. David, L. del Buono, P. Leruste, H. B. O'Connell. The Pion Form Factor Within the Hidden Local Symmetry Model. European Physical Journal C: Particles and Fields, Springer Verlag (Germany), 2003, 29, pp.397-411. ⟨10.1140/epjc/s2003-01234-1⟩. ⟨in2p3-00184917⟩

Record views