short, due to Coulomb interactions, a shift of protons takes place from low to high incident energies. The effect of the Coulomb interactions can be checked by taking the double ratio, which is discussed in Fig. \[fig:7\]]{}.

-   [The contribution of pions from secondary-chance nucleon-nucleon collisions might increase with the beam energy. If a first-chance nucleon-nucleon collision converts a neutron to a proton by producing a $\pi^-$, then subsequent collisions of the energetic protons can convert them back to neutrons by producing a $\pi^+$. Therefore, at sufficiently high energy, the neutrons, which are produced due to symmetry energy, are changing into the protons and further producing $\pi$’s, which will lead to a decease in the neutron-to-proton ratio. This can be confirmed by using the double ratio concept. If the double ratio is still deceasing with incident energy, then it means that, in addition to the Coulomb interactions, the phenomenon of secondary nucleon-nucleon collisions is also very important.]{}

One more point of interest is that the difference between the soft and stiff symmetry energies at freeze-out time is found to decrease with incident energy for free nucleons, while it increases for LCPs. Of the above two reasons, the first one is 