Binding Energy of 4He by Mass Defect?

RealQM gives using this code the following binding energy E per nucleon (in MeV) of atomic nuclei with charge Z=1,2,...,8, assuming a change of spatial scale from atom to nucleus with a factor $10^6$:

• Z=1  E = -0.5   2H
• Z=2  E =  -1.0  4He
• Z=3  E = -2.2   6Li
• Z=4  E = -3.2   8Be
• Z=5  E =  -5.0  10B
• Z=6  E = -5.5   12C
• Z=7  E = -6.5    14N
• Z=8  E = -6.6    16O

We see a nearly linear increase from Z=1 to Z=5 followed by much slower increase into constant value. 

We compare with the following list values (in MeV):

• Z=1  E = -0.86   2H
• Z=2  E =  -6.82  4He
• Z=3  E = -5.08
• Z=4  E = -6.81
• Z=5  E =  -6.22
• Z=6  E = -7.42
• Z=7  E = -7.22
• Z=8  E = -7.72

We see a very quick jump from 2H with Z=1 to 4He into nearly constant value, thus without the gradual increase suggested by RealQM. The explanation by StdQM for the surprisingly large jump is very complicated. A fusion process with two 2H being combined into one 4He would thus deliver about 25 MeV, to be compared with 2 MeV for RealQM. 

In this situation, it is natural to ask how the large binding energy for 4He is determined in StdQM. We recall that the fusion of two 2H into one 4He is the fusion process fueling the Sun. It is impossible to directly measure the energy release in a fusion process and so it is instead determined according to a certain standard, where mass is traded for energy according to Einstein's $E=mc^2$. But because of the factor $c^2$ is very large, the mass lost or mass defect in a fusion process is too small to be directly measured. The mass defect is instead computed according to a certain standard, from which the binding energy is computed using $E=mc^2$. 

We are thus led to ask if the large computed large binding energy of 4He is the real one? Is it possible that the smaller jump by RealQM is closer to reality? Which value is relevant for the Sun: 25 or 2? How can this question be answered?

 

We meet here a a situation where a certain standard procedure replaces direct measurement and the question is if the procedure captures reality.