Author/Authors :
A. Donnachie، نويسنده , , P.V. Landshoff، نويسنده ,
Abstract :
New structure-function data are in excellent agreement with the existence of a hard pomeron, with intercept about 1.4. It gives a very economical description of the data. Having fixed 2 parameters from the data for the real-photon cross section σγp, we need just 5 further parameters to fit the data for F2(x,Q2) with x⩽0.001. The available data range from Q2=0.045 to 35 GeV2. With guesses consistent with dimensional counting for the x dependences of our three separate terms, the fit extends well to larger x and to Q2=5000 GeV2. With no additional parameters, it gives a good description of data for the charm structure function F2c(x,Q2) from Q2=0 to 130 GeV2. The two pomerons also give a good description of both the W and the t dependence of γp→J/ψp.