Nuclear responses of the fluorine (a) and the iodine (b) targets considering two completely different types of interactions. On a more specific level, we show, in red, the nuclear responses for the “standard” SI contact interaction, while in blue those for another kind of interaction described in the nonrelativistic limit by the operator . The different hatching refers instead to the possible choices of nucleon pairs in the nucleus. In particular, the solid, dashed, and dotted lines are for , , and pairs, while the thick ones are obtained by summing over all of them (total nuclear responses). Notice that the total nuclear responses for the “standard” SI contact interaction (thick red lines) reduce to , where is the customary Helm form factor [33].
