Measurement of the e^+e^- p p^0 cross section at s=2. 1000-3. 0800 GeV

The process e^+e^- pp^0 is studied at 20 center-of-mass energies ranging from 2. 1000 to 3. 0800 GeV using 636. 8 pb^-1 of data collected with the BESIII detector operating at the BEPCII collider. The Born cross sections for e^+e^- pp^0 are measured with high precision. Since the lowest center-of-mass energy, 2. 1000 GeV, is less than 90 MeV above the pp⁰ energy threshold, we can probe the threshold behavior for this reaction. However, no anomalous threshold enhancement is found in the cross sections for e^+e^- pp^0.