I LABORATORI

The muon (/ˈmjuːɒn/; from the Greek letter mu (μ) used to represent it) is an elementary particle similar to the electron, with unitary negative electric charge of −1 and a spin of 1⁄2, but with a much greater mass (105.7 MeV/c2). It is classified as a lepton, together with the electron (mass 0.511 MeV/c2), the tau (mass 1777.8 MeV/c2), and the three neutrinos. As is the case with other leptons, the muon is not believed to have any sub-structure; namely, it is not thought to be composed of any simpler particles. The muon is an unstable subatomic particle with a mean lifetime of 2.2 µs. Among all known subatomic particles, only the neutron and some atomic nuclei have a longer decay lifetime; others decay significantly faster. The decay of the muon (as well as of the neutron, the longest-lived unstable baryon), is mediated by the weak interaction exclusively. Muon decay always produces at least three particles, which must include an electron of the same charge as the muon and two neutrinos of different types.

To try to figure out why a moving muon is decimating about 12 times later, I would like to try to analyze the experimental fact, let's deliberately leave the chance that time may slow down with speed, since we did not find a logical reason , let’s try to understand the true mechanical functioning of this particle. We know that muon is a particle with a negative charge and a mass of 105.6 MeV / c rest, about 207 times the mass of the electron; Since their interactions are similar to those of the electron, a muon can also be thought of as a heavy electron, we also know that its velocity is close to that of light, because it is a product of very energetic cosmic rays; the muon as I have already said is an unstable particle and its duration has been measured in 2.10 seconds "stopped", but the muons arriving on Earth are not firm, what happens to a massive particle if it is carried at a speed close to that of light? Here, too, the theory of relativity could help us, in fact, it tells us that the rest mass increases with the speed increase, just below the Fig. 9.1 shows the formula explaining the phenomenon.

Do you remember the chapter on mass growth? Now we know that there is no mass increase in reality, here can only be an increase in inertia of the mass that gives the possibility to accumulate so much kinetic energy in the mass and this inertia tends to infinity at the speed of light. Here relativistic physicists argue that muon decay is an experimental fact that certifies relativity, perhaps they were too hurried, they did not look at what really happened inside the muon. It is important to keep in mind that muon is a particle generated by the pure energy of very energetic cosmic rays that impacting the high atmosphere touch other particles, protons with mass and trigger the "creation" of the muon, probably more than the slowdown of time the solution is right in the mass of the particle, in fact, if we read the relativistic formula figure 9.1 we understand that the mass of the muon is subjected to a scary force in 'Cross our atmosphere. So why should we use this relativistic formula to justify the slowdown of time for the muon?

The speed as kinetic energy can be very vital for unstable particles with mass, this can stretch much their decay, do note that we are talking about decay, then the muon consumed their energy decade transforming into an electron and two neutrinos, what can invalidate a particle dying faster if its not the lack of bike? I.e. removing the kinetic energy given by its velocity of the particle with mass of the muon. Here the problem is not the experimental facts verified, is their correct interpretation. In Figure 9.2 this formula applied to the experiment does not certify the slowing of time confirming Einstein's theory of relativity, but only certifies a muon decay different given time in seconds from his inertia of mass undergoes a great speed. These two topics were already covered in chapter inertia increases with the speed and behavior of mass with velocity. Are the two topics that explain well the high accumulation of kinetic energy and the retarded muon decay. Understand that the muon at that speed undergoes stress that lead to change the composition of matter itself, because the stresses in play at that speed with the addition of air friction can be substantial. We speak of a particle with rest mass of 105.6 MeV/c, about 207 times electron mass, for a particle at those speeds in the atmosphere be 207 times greater is anyway an enormity. That's why a muon in motion has a delay in its decay unlike a muon still. The formula in Figure 9.2 can be considered a non-relativistic formula, this computes only the muon decay time delayed when subjected to a speed close to the speed of light.  

Translation : Francesca Carannante, Federica Iannuzzi.