Particle physics: why do we need to do this, and why in this way

Who cares about particles? Why are physicists specializing in them so interested in them?

In fact, we are not interested in the particles themselves.

Here is an analogy: imagine that you were interested in the cities of the Roman Empire and how they functioned. Because of this, you can start learning Roman architecture. You might be interested in how they built their buildings and aqueducts. Then, you will probably move on to the reliability of their arches and foundations, and from them to the properties of bricks and mortar. But you are not interested in bricks and mortar - these are only the means to achieve the goal. You want to consider them as part of the more general questions of the design and construction of Roman buildings, their beauty and their reliability, which enabled them to survive the centuries.

Nature is the most fruitful and ancient architect. We live surrounded by beauty and mysteries - oaks and volcanoes, sunsets and storms, a beautiful moon and innumerable sand grains on the beach. A couple of centuries ago, scientists concluded that the diversity of this architecture can be better understood if we accept that matter consists of various atoms - "elements". So they began to be interested in atoms, the "elementary" building blocks of nature, as they were then thinking.

But, as it turned out, this was only the beginning, as it turned out that there are dozens of different types of atoms, seriously differing in chemical transformations and the ability to emit light. In an attempt to understand the diversity and behavior of atoms, scientists realized that they were architectural forms built from even smaller particles: electrons surrounding the atomic nucleus, held together by cementing them with electrical forces. And in the nuclei themselves there is also architecture, with protons and neutrons, held together by cementing them with strong interaction. Along the way, another force was discovered, weak interaction, often more destructive than creative power.
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The discovery of new levels of architecture not only provided explanations for elementary chemical processes, as well as the emission and absorption of light, but also gave access to the solution of other secrets - the principles of stars, radioactivity, and access to enormous danger hidden in the core energy. The approach of “bricks and cement” became the key to unlocking many secrets during the 20th century.

This, of course, is a quasi-historical sketch, not an exact narrative of the story. The real story is richer, more complex and beyond my reach.

By 1950, it was known that protons and neutrons of atomic nuclei have many cousins: other hadrons with such names as pions , kaons , delta-baryons , ro-mesons , and others. This complexity was a sign of a regular architecture. In the early 1970s, a new understanding of these particles appeared, as objects consisting of quarks , antiquarks, and gluons , fastened by strong interaction.

Particle physics specialists are scientists who are interested in the architecture of nature at the level of bricks and cement, reliability and destructibility. What are the fundamental building blocks that hold them together or separate them? How do they organize and form the basis of the huge variety of structures that we observe in the Universe?

From the beginning of the 1960s, it was gradually understood that the properties of the world we inhabited required the presence of some substance filling the Universe — a non-zero field, as we by definition call the Higgs field — affecting the properties of many particles in nature. Without the Higgs field, the surrounding architecture would have collapsed. Understanding what this field is and how it works is one of the central projects of today's specialists in particle physics, and the main justification for the construction of the Large Hadron Collider (BAC). What secrets will be revealed in the process of learning? No one knows yet.

Why, then, did physicists necessarily have to build giant atom smashers?

Oh, how I hate this term! We do not collide atoms, we collide subatomic particles: protons that are 100,000 times smaller than atoms (along the radius), or electrons that are 1000 times smaller than protons! This is how to confuse the collision of the planets with the collision of two oil tankers or two bullets.

Okay, okay, calm down already. So why do physicists have to push protons or other subatomic particles? Is it possible to do something less destructive?

An analogy is often given that using colliders (more precisely, colliders of subatomic particles) in physics is similar to breaking exact chronometers together in an attempt to study their work on details that depart from them. This analogy makes sense, but it does not take into account something important.

The collision of ultrahigh-energy subatomic particles is not just an act of destruction. This is, for the most part, an act of creation.

This is an amazing property of nature - if you put enough energy into a sufficiently small space, it can sometimes produce particles that were not there before. That is why we arrange the collisions of high-energy particles. The technology with energy compression is the only one known that allows obtaining new or extremely rare particles that people have never seen before. We, for example, have no other way to get Higgs particles.

So we are interested not in the collision of chronometers. We already know a lot about them - we already have a decent understanding of the protons colliding in the LHC. We hope to discover what was not in the clock - we have already studied quarks and gluons, bricks and proton cement in sufficient detail. We have to correct the analogy. Rather, we push the clock together in the hope that as a result of the energy of the collision a cell phone will appear.

Sounds pretty crazy. But nature is amazing and unusual, and rare heavy particles are produced daily at the LHC. Precisely in order to create Higgs particles, and possibly other unexpected phenomena, we sacrifice protons on the altars of the LHC.