Figure 1: Energy dependence of the elastic slope parameter for proton-proton scattering for low domain. Experimental points from fitted samples are indicated as •; unfitted points are indicated as . The dot curve is the fit of experimental slope by the function (4a), thick solid—by (4b), dashed—by (4c), thin solid—by (4d). The shaded band corresponds to the spread of fitting functions for previous analysis [9].