How are baryons fundamentally different from leptons?

Understanding the distinction between baryons and leptons is central to comprehending the fundamental building blocks of the universe. Baryons, like the familiar protons and neutrons found in atomic nuclei, are composite particles made up of smaller entities known as quarks. There are always three quarks in a baryon, which interact with each other through the strong nuclear force.

In contrast, leptons are elementary particles, meaning they are not believed to be composed of anything simpler. The most well-known lepton is the electron, essential for chemical reactions and the conveyance of electricity. Unlike baryons, leptons do not participate in the strong nuclear force, which fundamentally differentiates them in terms of how they interact with other particles and forces in the universe.

Particle physics is the branch of physics that delves into the nature of elementary particles and their interactions. It is a field that has revolutionized our understanding of the universe at its smallest scale. Within this domain, baryons and leptons serve as two primary categories of particles that physicists study to demystify the fabric of reality. Particle physics encompasses the investigation of how these particles are structured, their behavior under various forces, and the roles they play in the cosmos.

Experiments in particle physics often take place in large accelerators that smash particles together at high speeds, allowing researchers to observe the resulting reactions and discover new particles or validate theoretical predictions. This field is central to answering fundamental questions about the universe and the very essence of matter.

Elementary particles are the smallest known building blocks of the universe. They include quarks, which combine to form baryons, and leptons like the electron, as well as particles that mediate forces such as photons for electromagnetic interactions. In the Standard Model of particle physics, these elementary particles are neither made of smaller components nor can they be divided into them.

Each elementary particle exhibits unique properties like mass, charge, and spin. Their interactions give rise to the complexity seen in the universe, from the formation of atoms to the creation of chemical compounds. Understanding elementary particles helps in solving the complex puzzles of how everything in the universe works, from the microscopic world to the cosmological scale.

The strong nuclear force is one of the four fundamental forces of nature and the most powerful of them all, albeit over short distances. It is the force responsible for holding the nucleus of an atom together, acting between the quarks within protons and neutrons, and consequently, between the protons and neutrons themselves. Without the strong force, atomic nuclei could not exist, as the electromagnetic force would push the positively charged protons apart.

This force is mediated by particles called gluons, which act as the 'glue' that binds quarks into baryons and keeps atomic nuclei intact. Because leptons do not contain quarks, they do not experience the strong nuclear force, which is a principle underlying their fundamental difference from baryons.

Electromagnetic interactions are one of the key types of fundamental forces in the universe, characterized by the interaction between charged particles. These forces are ubiquitous, governing everything from the attraction and repulsion between charged particles to the way light interacts with matter.

Both baryons and leptons can participate in electromagnetic interactions if they have a charge; for example, protons have a positive charge while electrons have a negative charge. When charged particles such as these move, they create electric currents and magnetic fields, which are the basis for the vast array of electromagnetic phenomena observed in the world. Unlike the strong nuclear force, the electromagnetic force has an infinite range but is many magnitudes weaker, allowing for various applications ranging from electromagnets to radio transmissions.