On the identification of the nuclear forward glory in heavy-ion scattering

Distinction between shadow and edge effects in heavy-ion elastic angular distributions

“…However, several methods [3,10,11] allow us to extract from the experimental data the modulus of the so-called "nuclear amplitude" f n ͑͒ defined through…”

“…The modulus ͉f n ͉͑͒ so obtained [10,11] In order to distinguish between shadow and edge or surface effects, we will invoke, by optical analogy, an extension [2] of Babinet's principle, which can be formulated as follows: the Fraunhofer diffraction pattern produced by an opaque screen and the one produced by a narrow slit having the shape of its edge, oscillate "180°out of phase," or in quadrature, i.e., the maxima of one pattern coincides with the minima of the other and vice versa. To verify that this phase rule also holds in heavy-ion scattering, we begin with the expression of the elastic amplitude f͑͒, separated as in Eq.…”

“…Figures 2 and 3 ing for the occurrence of surface effects in the forward direction, one should have in mind that for ӷ 1 these effects will be hidden by Coulomb scattering. However, a simple method [11] allows us to extract ͉f n ͉͑͒ from the measured scattering cross section d / d⍀, providing sufficiently accurate experimental data are available at very small angles. It has been shown [11] that if ӷ 1 and Ӷ g , the following relation holds:…”

“…with [11] ͉f n ͑0͉͒ = 43 fm for 16 O+ 28 Si and ͉f n ͑0͉͒ = 28 fm for 12 C+ 28 Si. Figure 8 displays the experimental data shown in Figs.…”