What is a quark in science
Pro Research Analysisby 
Searched over 200M research papers
Understanding Quarks in Science
Introduction to Quarks: Fundamental Particles
Quarks are fundamental particles that form the building blocks of matter. They are considered elementary particles, similar to electrons and neutrinos, and are integral to the structure of hadrons, which include protons and neutrons 12. The concept of quarks was introduced in the 1960s to explain the properties and behaviors of hadrons, which were observed to follow a specific pattern known as the "eightfold way" 25.
Discovery and Evidence of Quarks
The existence of quarks was first suggested by Murray Gell-Mann and George Zweig in 1964. They proposed that hadrons were not elementary particles but were composed of three subparticles, which Gell-Mann named "quarks" . The key experimental evidence for quarks came from inelastic electron-nucleon scattering experiments conducted at the Stanford Linear Accelerator Center between 1967 and 1973 . These experiments, along with subsequent theoretical and experimental advances, confirmed the existence of quarks and solidified their role in the Standard Model of particle physics 12.
Types of Quarks and Their Properties
There are six types of quarks, known as flavors: up, down, charm, strange, top, and bottom. Each quark carries a fractional electric charge, either +2/3 or -1/3 of the electron's charge 47. The up, charm, and top quarks have a charge of +2/3, while the down, strange, and bottom quarks have a charge of -1/3. Quarks combine in specific ways to form hadrons: baryons (such as protons and neutrons) are made of three quarks, while mesons are made of a quark-antiquark pair .
Quarks in the Standard Model and Beyond
Quarks are a central component of the Standard Model of particle physics, which describes the fundamental particles and their interactions. The strong interaction between quarks is described by Quantum Chromodynamics (QCD), a theory that explains how quarks are held together by gluons, the carriers of the strong force . One of the unique features of QCD is "color confinement," which means that quarks cannot be isolated and observed as free particles; they are always found within hadrons .
The Top Quark: A Special Case
The top quark, discovered in 1995 at Fermilab, is the heaviest of all quarks and plays a crucial role in high-energy physics research. Its large mass makes it a key subject of study for understanding physics beyond the Standard Model 28. Researchers hope that studying the top quark will provide insights into new physics and help answer fundamental questions about the universe .
Conclusion
Quarks are fundamental particles that form the basis of hadrons and are essential to our understanding of matter. Their discovery and the subsequent development of the Standard Model have revolutionized particle physics. Ongoing research, particularly into the properties of the top quark, continues to push the boundaries of our knowledge and may lead to new discoveries beyond the current theoretical framework.
Sources and full results
Most relevant research papers on this topic