# Particle Physics

## What is Particle Physics?

• It is a branch of physics that studies the basic elements of matter and radiation and the interaction between them. The word particle can refer to various types of very small objects, but this branch usually investigates the irreducibly smallest detectable particles.
• It is also called as “high energy physics” as many elementary particles don’t come under normal circumstances in nature. But, it can be identified during the energetic collision of other particles.

## Modern Particle Physics

The modern particle physics research is focused on subatomic particles with less structure than atoms. These atomic constituents, like particles of protons, electrons and neutrons, are produced by radioactive and scattering processes.

## Standard Model

• The standard model of particle physics is a theory related to the electromagnetic, nuclear interactions and also classifying the subatomic particles.
• This model was developed in the latter half of the 20th century, as a collaborative effort of scientists around the world. The development of the Standard Model was driven by a theoretical and experimental particle.

Standard Model of Particle Physics

• As currently formulated the Standard Model has 61 elementary particles. The standard model contains 24 fundamental fermions, includes 12 particles and their associated antiparticles, which are the constituents of mater. Back in 2012, the standard model predicts the existence of Higgs Boson, which was known as the last piece.
• However, recently a particle named as God’s particle is found that is consistent with the Higgs Boson particle and has stepped forward in the completion of the standard model of particle physics.

## Theoretical Particle Physics

Theoretical physics is a branch of physics which employs mathematical models and abstractions of physical objects and systems to rationalize, explain and predict natural phenomena. While, there are several efforts being made in theoretical particle physics, in an attempt to develop the models, theoretical framework, and mathematical tools to understand current experiments and make predictions for future experiments.

### Uses

• Particle physics is used to produce medical isotopes which are used in the PET imaging and external beam radiotherapy.
• Helps to achieve the concept of a superconductor.
• Touchscreen technologies and the World Wide Web were developed at CERN institute for particle physics.
• Some other fields that use particle physics are workforce development, medicine, industries, science, and national security etc.

### Particle Physics Formulas

Following is the table explaining the formulas used in particle physics with their symbols:

 Quantity Defining equation Symbols used Number of atoms N0=N+ND N is the number of atoms remaining at time t N0 is the initial number of atoms at time t ND is the number atoms decayed at time t Mass number A=Z+N A=atomic mass=mass number=sum of protons and neutrons N is the number of neutrons Z=atomic number=number of protons=number of neutrons Radioactive decay $$\frac{dN}{dt}=-\lambda N$$$$N=N_{0}e^{-\lambda t}$$ N0 is the initial number of atoms N is the number of atoms at time t 𝝀 is the decay constant t is the time