Particle Physics: Learn about Standard Model, Theory, Formulas & Applications

We may have heard about protons, electrons, neutrons, neutrinos and even sometimes quarks as these particles are often featured in the news of scientific development and discoveries. All of these are referred to as subatomic particles and these are too small to be seen even in high-intensity microscopes. While molecules and atoms are considered to be the basic elements of familiar substances that we can observe in our surroundings and feel. We have to “look” within atoms in order to study the “elementary” subatomic particles and to understand the nature of our universe. The science of this study is referred to as Particle Physics, Elementary Particle Physics or sometimes High Energy Physics (HEP).

In this Physics article, we are going to study about Particle Physics and its application in understanding the Universe.

Particle Physics

Atoms were believed to be postulated long ago by the Greek philosopher Democritus. Until the beginning of the 20th century, atoms were thought to be the fundamental and indivisible building blocks of all forms of matter. As time passed and new scientific theories developed, Electrons, Protons and neutrons came to be regarded as the fundamental particles of nature. They were discovered through a series of experiments by Rutherford, Chadwick and Thomson. An atom consists of mostly empty space with electrons surrounding a dense central nucleus. The nucleus is composed of protons and neutrons.

Particle Physics is actually a branch of Physics that deals with the study of elementary constituents of matter like quarks and leptons and radiation and the interactions between them.

Standard Model of Particle Physics

Particle physicists can depict the behaviour of all the known subatomic particles inside a single theoretical structural setup called the Standard Model. It is considered to be the scientists’ current best theory that actually provides a description of the fundamental and building elements of the universe. It explains how particles called quarks and leptons make up all the matter in our surroundings. It also provides a description about how the forces carrying particles influence the quarks and leptons.

Three out of four fundamental forces in nature including strong force, weak force and electromagnetism except gravitational force are explained adequately using the Standard Model of particle Physics. The Standard Model is the fruit of many hard years of international effort through multiple experiments, theoretical ideas and intense discussions. We can summarize it this way:

All of the known matter in the Universe today is composed of quarks and leptons, held together by fundamental forces which are represented by the exchange of particles known as gauge bosons.

Theoretical Particle Physics

The objective of particle physics was to develop a deep understanding of the fundamental constituents of matter and the nature of their mutual interactions. Particle theorists attempt to achieve this goal in various ways. But, they depend on the outcomes of their experiments to actually test theoretical ideas. It is actually the study of how to describe nature with greater mathematical precision.

 

History of Particle Physics

As one begins to focus on increasingly small distances in physics, at a scale of around an Angstrom ( i.e. ) one comes to learn about atoms. At this scale, classical mechanics no longer finds its application and quantum mechanics comes into existence. This is also the scale at which particle physics generally began since electrons become clear at this stage and are considered to be fundamental particles.

As the distance scale keeps on contracting, then at around 1 fm (i.e. 10-15 m) one can easily track down the atomic nucleus. Superficially, the nucleus seems to be composed of protons and neutrons. In any case, as the scale gets much smaller it becomes apparent and is found that protons and neutrons themselves are composed of smaller particles called quarks. This is the domain of particle physics.

Particle Physics Formulas

Quantity	Defining Equation	Symbols Used
Number of Atoms		Here,   N : Number of atoms at time,t : initial number of atom : Number of atoms decayed in time t
Mass Number	A = Z + N	Here,   A = atomic mass number Z = Atomic number N = number of neutrons
Radioactive Decay		Here,   : Decay constant : initial number of atoms N : number of atoms at time, t. t: time

Application of Particle Physics

 

Particle Physics has actually revolutionised the way we observe the universe. It also made a significant amount of impact on other scientific areas like Quantum mechanics and also helped improve the lives of people around the world. It also trained the new generation of scientists for upcoming challenges in the field of subatomic particles. Here are some other day-to-day applications of Particles physics:

• Tools like complex accelerators, sensitive detectors, grid computing, high volume data storage and analysis are all based on Particle Physics. These tools are making a signature and long-lasting impact on the quality of life for people across the globe.
• The theories and tools developed based on particle physics found their application in other areas of science like biology, chemistry, material science and computer science that enabled advancement in these fields.

Let’s prepare, practice, score high and get top ranks in all the competitive examinations with the help of the Testbook App. This app is built to create a method of concept learning for students preparing for competitive exams. Just download it and get started. So download the Testbook App from here now and get started in your journey of preparation.