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We analyze the accuracy of the pion elastic form factor predicted by alocal-duality (LD) version of dispersive sum rules. To probe the precision ofthis theoretical approach, we adopt potential models with interactions thatinvolve both Coulomb and confining terms. In this case, the exact form factormay be obtained from the solution of the Schroedinger equation and confrontedwith the LD sum rule results. We use parameter values appropriate for hadronphysics and observe that, independently of the details of the confininginteraction, the deviation of the LD form factor from the exact form factorculminates in the region Q^2~4-6 GeV^2. For larger Q^2, the accuracy of the LDdescription increases rather fast with Q^2. A similar picture is expected forQCD. For the pion form factor, existing data suggest that the LD limit may bereached already at the relatively low values Q^2=4-10 GeV^2. Thus, largedeviations of the pion form factor from the behaviour predicted by LD QCD sumrules for higher values of Q^2, as found by some recent analyses, appear to usquite improbable. New accurate data on the pion form factor at Q^2=4-10 GeV^2expected soon from JLab will have important implications for the behaviour ofthe pion form factor in a broad Q^2 range up to asymptotically large values ofQ^2.

Accuracy of the pion elastic form factor extracted from a local-duality sum rule