Nuclear form factor, the graph F2(q) vs. q (fm-1)

[Yuen]

TL;DR

How to obtain the graph F2(q) vs. q (fm-1) from the graph F2(q2) vs. q2 (fm-2)?

In the article J. R. Ficence, ,,,, I. Sick, Phys. Lett. B 32, 460 (1970), Fig. 1, there is graph F(q) vs. q (fm-1).
In the article J. S. McCarthy, I. Sick, …, Phys. Rev. Lett. 25, 884 (1970), Fig. 1, there is graph F2(q2) vs. q2 (fm-2).
How to obtain the graph F2(q) vs. q (fm-1) from the graph F2(q2) vs. q2 (fm-2)?

In the book Subatomic Physics (E. M Henley, A. Garcia, 3rd ed. (2007)), p. 137, it is spherically symmetric, Eq. (6.6). Since f no longer depends 0n the direction of q but only on its magnitude, it is now written as f(q2).
In the book Particles and Nuclei (P. Povh et al., 5th ed. (2006), p. 62, spherical symmetric …, the form factor only depends on the momentum transfer q. We symbolise this fact by writing the form factor as F(q2).
How to obtain the graph F2(q) vs. q (fm-1) from the graph F2(q2) vs. q2 (fm-2)?

I think in the graph F2(q2) vs. q2 (fm-2), q2 is a dummy variable. We can just replace F2(q2) by F2(q), and q2 (fm-2) by q (fm-1).
In the book Subatomic Physics, p. 137, ‘it is now written as f(q2)’ , and the book Particles and Nuclei, p. 62, ‘We symbolize
this fact by writing the form actor as F(q2)’ are unnecessary.

Could someone please give me the answer? Thanks.

 

[Yuen]

In fact, In the book Subatomic Physics, p. 137, Eq. (6.6), we can just use f(q) where q is a scalar.