It would appear to a layman such as myself that these heavier unstable particles are just transient interplay of the stable forms
![unstable lepton muon unstable lepton muon](http://www7b.biglobe.ne.jp/~kcy05t/zu/coll/lar7.gif)
It's similar for some other particles: "Experiments don’t detect the Higgs boson directly – instead, its existence is inferred by looking at the particles left behind when it decays". Nobody has actually seen a Z-boson, or a track. Still, even a resonance is more stable that the inverse of its mass, $ t_$ seconds. So even if W, Z or the top decay faster than any resonance, they decay slow enough compared with its mass. The "resonances" and "excited states" are in the huge clud with very small lifetimes, or wide decay widths. The neutron is a lot more stable, so it is not pictured here, it is down in the plot then.
![unstable lepton muon unstable lepton muon](http://article.sapub.org/image/10.5923.j.fs.20170701.01_001.gif)
Horizontal is mass, vertical is decay width, which is about the inverse of halflife. Most of the particles decaying via beta have a half-live about inverse the fifth power of its mass, time a constant.
![unstable lepton muon unstable lepton muon](https://cerncourier.com/wp-content/uploads/2019/05/CCMayJun19_meg-boxpic-1024x581.jpg)
Most of the particles decaying via photons have a half-live about inverse the cube of its mass, times a constant. Let me first consider all the "particles" listed in the particle data group file. But they will fit the general pattern, you will see. Sorry I am not answering directly about "the standard model", this is quarks and leptons. Inmediately is not really true, there is some proportionality. It is interesting to note though, that string theories, which can embed the standard model of particle physics, posit one kind of "particle", instead of a point, a one dimensional string where the particles are vibrational levels of the string which display the standard model group representations. It is the different quantum numbers, conserved by different interactions, that give the particular group structures observed and finally the particle table. When I started in 1963, different models,( four fermi interactions, vector meson dominance, Regge poles,eightfold way) were in fashion, which due to the accumulation of data slowly morphed into the standard model. The standard model took years to develop. The standard model says that the unstable particles are an artifact of the low energy in which one observes them, at high enough energies they are no longer unstable because they have zero mass. It would appear to a layman such as myself that these heavier unstable particles are just transient interplay of the stable forms. They have a separate existence in the group symmetries due to the quantum numbers which give a unique niche for each particle.Īfter the electroweak symmetry is broken at about 246 GeV and below, the Higgs vacuum expectation value, the particles acquire the masses we have measured in the laboratory and the composites display the beautiful group representations that gave rise to the standard model to begin with. that there exists no Higgs field to give masses to the particles entering in the table, and thus at those energies all these particles are stable, since there cannot be a lower energy state to which they can decay. The basic hypothesis is that at large energies the symmetry is unbroken, i.e. This model incorporates a group symmetry ( SU(3)xSU(2)xU(1) ) which identifies it. The Standard Model of elementary particles (more schematic depiction), with the three generations of matter, gauge bosons in the fourth column, and the Higgs boson in the fifth. The standard model of particle physics has a relatively small number of elementary point (0 dimensional) particles and is a model of a large number of observations encapsulated in their simplest form. All the hadronic resonances are composite particles of quark antiquark combinations as well as the neutron. Here I will only consider elementary, non composite particles. I’d love to learn some math to supplement and inform this intuitive view.How can the unstable particles of the standard model be considered particles in their own right if they immediately decay into stable particles? Not saying that in a literal sense, but just in the sense that electrons are things which seem to have a certain intrinsic tangledness or vortexness to them. The way I imagine this intuitively is something along the lines of Lord Kelvin’s old knots-in-the-ether picture. Do you know where I can read more about how this decay via weak interaction works? I understand that electrons don’t decay on their own since they have charge, and no lower mass negatively charged particle to decay into (but bring a positron around and you can make photons since the net charge becomes zero).