New attempts to measure the size of the proton put scientists in a deadlock. The results were again different from the previous ones, obtained using other methods, and the reasons for these differences, the scientists can not find.
This time, physicists have measured the size of a proton by the method of laser spectroscopy. They irradiated hydrogen-1 formed of two particles (protons and electrons), the muon flux, which are, like neutrinos, electrons close relatives. During irradiation in some atoms muon held the seat of the electron, resulting in a muonic hydrogen. According to the emission spectrum of the hydrogen physicists have been able to estimate the size of the proton.
It is not clear why, but the radius of the proton was found to be 0.84 femtometra (10 -15 degrees meters), which is less than the previously calculated size of 4%. The results of the new measurements coincide with the previously obtained using the same values of the muon method, but is not coordinated with the measurements of the radius of the proton, made the other way.
According to one version of scientists, in theory, such a discrepancy in results may be due to the fact that the interaction between the proton and the muon is not subject to the laws of modern physics. Most experts believe this explanation is unlikely, but so far, and another can not offer.