D0 Measurement of the elastic p anti-p differential cross section for 0.25<|t|<1.2-GeV**2 at s**(1/2) = 1.96-TeV

A measurement of the p{bar p} elastic differential cross section, d{sigma}/d|t|, is presented as a function of the four-momentum transfer squared, |t|. The results are obtained from L {approx} 30 nb{sup -1} of data collected by the D0 experiment at {radical}s = 1.96 TeV at the Fermilab Tevatron during a two-day period optimized for low |t| acceptance. In the range 0.25 < |t| < 0.6 GeV{sup 2} the differential cross section is observed to decay more rapidly than in the range 0.6 < |t| < 1.2 GeV2, where a much more gradual decay is observed. A fit of the form d{sigma}/d|t| = C exp-b|t|, performed in the range 0.25 < |t| < 0.6 GeV{sup 2}, yields an exponential slope parameter of b = 16.54 {+-} 0.10(stat) {+-} 0.80(syst) GeV{sup -2}.