Reaction<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:mi>γ</mml:mi><mml:mi>p</mml:mi><mml:mo>→</mml:mo><mml:mi>p</mml:mi><mml:mrow><mml:msup><mml:mrow><mml:mi>ρ</mml:mi></mml:mrow><mml:mrow><mml:mn>0</mml:mn></mml:mrow></mml:msup></mml:mrow></mml:math>with Linearly Polarized Photons at 2.8 and 4.7 GeV: Cross Sections and the<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:mrow><mml:msup><mml:mrow><mml:mi>ρ</mml:mi></mml:mrow><mml:mrow><mml:mn>0</mml:mn></mml:mrow></mml:msup></mml:mrow></mml:math>Mass Shift

Rho photoproduction is studied at 2.8 and 4.7 GeV using a linearly polarized photon beam in a hydrogen bubble chamber. The dependence of the ${\ensuremath{\rho}}^{0}$ mass shape on the momentum transfer is inconsistent with the Ross-Stodolsky factor. The production of ${\ensuremath{\pi}}^{+}{\ensuremath{\pi}}^{\ensuremath{-}}$ pairs in the $s$-channel c.m. helicity-conserving $p$-wave state accounts for almost all events in the $\ensuremath{\rho}$ region. Evidence is presented for an interference of ${\ensuremath{\rho}}^{0}$ production with background. The data are compared with the S\"oding model and total and differential cross sections for ${\ensuremath{\rho}}^{0}$ production are presented.