Particle physics

In the standard model, the particle considered to be an elementary particle is a(n)

• proton
• neutron
• electron
• alpha particle

These are light, elementary particles that are not made up of quarks.

• Gluons

• Electrons

• Leptons

• Baryon

These are the category of hadrons that contain three quarks. This distinguishes them from mesons, which contain two (1 quark and 1 antiquark).

• Gluons

• Electrons

• Leptons

• Baryons

There are three families of leptons;

• electron, muon, and pi.

• electron, muon, and tau.

• electron, pi and tau.

• electron, pi and neutrino.

Protons and neutrons are thought to consist of smaller particles called quarks.

The ‘up’ quark has a charge of +(2/3)e

the ‘down’ quark has a charge of –(1/3) e,

where e is the elementary charge (+1.6 x 10^–19C).

How many up quarks and down quarks must a proton contain?

• 0 up quark, 3 down quarks

• 1 up quark, 1 down quark

• 1 up quark, 2 down quarks

• 2 up quarks, 1 down quark

Which quarks form a neutron?

• up, up, down

• down, down, down

• up, up, up

• up, down, down

Why are protons in particle accelerated to close to the speed of light in particle accelerators?

• To conserve momentum

• To create mini black holes

• So extra energy is available to create new mass

• Because time slows down close to the speed of light

What is the job of the magnetic field in a cyclotron?

• Create a force perpendicular to the motion of the particle, which acts a centripetal force

• To accelerate the particle between the dees

• To apply a force parallel to the direction of motion of the particle, which acts as the centripetal force.

• So the direction of the force can be alternated every half turn

In a particle decay, new particles move off in opposite directions to conserve...

• charge and kinetic energy

• momentum and charge

• momentum and quark number

• momentum and strangeness

a hadron with one quark and one antiquark

• neutron

• baryon

• hadron

• meson