Can the Pion's Charge Radius be Large?
Phys. Rev. D 6, 3149 – Published 1 December, 1972
DOI: https://doi.org/10.1103/PhysRevD.6.3149
Abstract
Analyticity has been used to derive dispersive inequalities which bound the spacelike behavior of the pion's charge form factor in terms of the timelike variation of the modulus of the form factor and the -wave scattering phase shift. The large charge radius, suggested by the Serpukhov-UCLA measurement of scattering, is only compatible with timelike data which involve a large -wave phase shift just above threshold.