Free Beyond the God Particle by Leon M. Lederman, Christopher T. Hill Page B

powerful new accelerators and various national laboratories came along. At one time there was a new energy frontier particle accelerator every few years or so, and a plethora of new “particles” and particle phenomena were discovered. Yes, we could stroll down memory lane and recount all of the history and structure of the Standard Model. Your eyes might glaze over, your eyelids becoming heavy. Rather, we'd like to veer off that traditional litany and do something a little different. We want to hop, skip, and jump to the Higgs boson as quickly as we can, to actually delve in and try to explain it to you in a way that is as close as we can get to how physicists understand it.
    Indeed, by the time physicists understood the details of the forces of nature, in particular the “radioactive” transmutations between these particles that involve the “weak force,” it was soon realized that some kind of “Higgs boson” was a necessity. This realization mainly came from the work of one of the architects of the Standard Model, 4 a theorist named Steven Weinberg (see chap. 1, note 14 ). There was no other way to make particles behave the way they do, and simultaneously to have mass, without something like a “Higgs mechanism.” Remarkably, one of the key ingredients to this revelation, the ingredient that mandated the theoretical existence of a Higgs boson, was revealed by the lowly muon (in concert with the charged pion, which also decays through the weak force into a muon and a neutrino). The pion and muon decays provided the major clue about the weak forces of elementary particles that would lead directly to the Higgs boson. It was in an almost incidental way that the muon revealed the essential aspect of the weak force that ultimately legislates the Higgs boson into existence. The unexpected and uninvited guest at our table, the muon, was actually a gift—perhaps this is the answer to Rabi's question as to why the muon was “ordered.”
    We also think that in the not-too-distant future humans will use the muon as a powerful practical tool, much like we use everything we discover in nature. In fact, muons are already providing themselves as new diagnostic tools that scientists use to study nuclear and atomic processes. In some quarters there is a fervent albeit long-shot hope that the muon might ultimately provide the catalyst needed to unleash the ultimate energy source—nuclearfusion—through a process known as “muon-catalyzed fusion.” 5 And we believe our favorite laboratory, Fermilab (or some other laboratory in another country, if the US government doesn't get its act together), will someday build a new type of high-energy particle collider—one that will literally rank as the most sophisticated thing humans ever built—a machine that collides muons— the Muon Collider . 6 There are many reasons why this is very good ideas—so let's now pop open some champagne and celebrate…
    THE LOWLY MUON
    As we've seen, people were expecting to observe the pion, with a mass of about 100 MeV, to confirm Yukawa's theory that explained the strong force between the neutron and proton and that holds together the atomic nucleus. Instead, Carl Anderson and Seth Neddermeyer, at Caltech in 1936, found the muon in the debris of cosmic rays that bombard the surface of the earth. 7 Muons are produced in the upper atmosphere when primary, very energetic cosmic rays from outer space collide with nuclei of atoms in the thin air. But even that story has a peculiar twist.
    How are muons produced in these collisions? Remarkably, we know today that pions are, indeed, immediately produced by the cosmic rays hitting atomic nuclei in atoms of nitrogen and oxygen in the earth's upper atmosphere. This happens because the pions are strongly coupled to nuclei (they are the glue that holds nuclei together, after all), and the cosmic rays are essentially protons colliding with other protons and neutrons in the nuclei of atoms in the