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## Particle Physics: Learn With Fun : Part III – Quarks

In last two episodes, we learnt about What is Particle Physics?, Standard Model & Antimatters. Now Our aim is to learn about next step- Quarks. So are you ready?

# Quarks?

What are these?

In our earlier classes, we read about charge in such a way that it can’t be rationalised. That meant any charge can only be an integer multiple of electron’s charge i.e., 1.6 x 10-19 Coloumbs. But Quarks deny this concept.
There are six types of quarks, in three pairs:

•The Up quarks & • Down quarks
• The Charm quarks & • Strange quarks
• The Top quarks  & • Bottom quarks

## Extras

1. Kindly note that there are also six – antiquarks:

• Anti Up & Anti Down Quarks
• Anti Charm & Anti Strange
• Anti Top & Anti Bottom

2. Top- Bottom are sometimes called Truth- Beauty.
3. You should know that there is no existence possible of a single Quark. Quark extists as Quarks. These form composite particles after combining, called Hadrons.
4. As mentioned, Quarks, like protons and electrons, have electric charge. However, their electric charges are fractional charges, either +2/3 or -1/3 (-2/3 and +1/3 for antiquarks), and they always arrange to form particles with an integer charge (ie. -1, 0, 1, 2…).

Flavour Electric Charge
(e)
u up +2/3
d down -1/3
c charm +2/3
s strange -1/3
t top +2/3
b bottom -1/3

Because quarks join with each other to form particles with integer charge, (i.e. HADRON, what earlier mentioned) not every kind of combination of quarks is possible.

There are two basic types of Hadrons:
Baryons:

These are composed of three quarks

Mesons:

These are made up of a quark and an antiquark.

# Baryons

Examples of baryon are the neutron and the proton.

The proton is composed of two up quarks and one down quark. As you can see, in the image, when the charges from the individual quarks are added up, you arrive at the familiar charge of +1 for the proton.

The neutron is made up of two down quarks and one up quark.

Adding the charges from the quarks up, we arrive at zero.

# Mesons

An example of a meson is the pion.

The Pion is composed of an up quark and a down antiquark. Because mesons are a combination of particle and antiparticle, they tend to be very unstable and decay very quickly.

So this was about Quarks!! Next article will be about counter friend of quarks- called Leptons. Enjoy, Share & Comment.

## Particle Physics- Learn With Fun – Part II- The Standard Model and The Antimatter Concept

We left previously on The Standard Model. So let Start!!

# The Standard Model

The Standard Model is a standard in particle physics. It’s a theoretical picture that describes how the different fundamental particles are organized and how they interact with each other along with the different forces.

# What is in it?

Briefly it states that: The elementary particles are split up into two families, namely the quarks and the leptons. Both of these families consist of six particles, split into three generations, with the first generation being the lightest, and the third the heaviest. Furthermore, there are four different force carrying particles which lead to the interactions between particles.

# Not Clear?

The table below shows this all a little bit more clearly.

Standard Model

All particles come under these two categories: Quarks & Leptons.

# So, is everything in the world made up of quarks and leptons?

Well, not quite. Let we learn about AntiMatter!!

# What’s Antimatter?

An interesting thing that has been discovered about matter particles, is that each one has a corresponding antiparticle.
The term “anti” may be a bit decieving, as it is still real matter. The only difference between a particle and it’s antiparticle is that an antiparticle has the opposite electrical charge.

Think of it as a mirror image. In our experience left and right are the only things to reverse when looking in the mirror. Similarly, in the particle world, charge is what reverses when looking in the “mirror”. This has mass, spin, and most other (quarks have something called colour charge which is also changed in the “mirror”) properties the same.

In general, an antiparticle is the particles name with “anti” in front of it. For example, the antiparticle of the proton is the antiproton. An exception to this rule is the electron, whose antiparticle is known as the positron, not anti-electron.

# At the End

An interesting fact about antimatter is that All of the universe is made up of matter as opposed to antimatter. This is somewhat of a mystery.

Now We’re ready to go for Quarks in a few days.