What is the smallest thing in the world

What is the smallest thing in the world? Chris Bellamy and Max Howells

How small is small n A grain of sand - 0. 001 m – Size of Earth • Size of the sun n An atom - 0. 000 001 m – Size of this room n A Proton - 0. 000 000 01 m – Proton is 1 mm across • 5 cm across n A Quark - 0. 000 000 000 01 m – 0. 001 mm across • 5 mm across

The Quark The Skittle Different Types Up Down Strange Different Flavours Red Yellow Purple Mix together Hadrons Protons Neutrons Mix together Marshmallows Pink White

The Quark n 3 in a proton n Cannot exist on its own n Different Types n Mix in different combinations

Experiment n Proton Up = Red Down = Yellow Strange = Purple - Up Up Down n Neutron - Up Down n Harris-on - Strange

Unfortunately it can’t exist! n Properties must add up to whole values Charge Number Strangeness Up 2/3 1/3 0 Down -1/3 0 Strange -1/3 -1 The harris-on had a charge of -2/3, Number of 2/3 and strangeness of -2 Any whole number combination can exist Only protons and neutrons are stable

Max Quark Anti Max Anti Quark The ‘anti photo’ has exactly the same size, but every single other colour is opposite The ‘particle’ and the ‘anti particle’ have the same mass, but all other properties e. g. charge are opposite

If they Collide…. n Annihilation, turn into energy

The Up Quark The Anti Up Quark Mass - 2/3 Charge - 2/3 Nucleon Number - 1/3 Mass - 1/3 n Charge - -2/3 n Nucleon Number - -1/3 n

What about the Electron? n Lepton n Does not contain quarks n It is fundamental n Like a teaser

Other Particles n Quarks mix in any combination, n Proton and Neutron stable n These both contain 3 quarks – The electron has no quarks and is stable – What if we had 3 anti quarks – Or a quark and an anti quark

Weird Names Fermions Quarks Hadrons Baryons Proton Λ 0 Σ- Quark and Anti Quark Electron Neutrino Anti Electron Neutron Lambda Sigma Leptons Meson 3 quarks or 3 anti quarks No Quarks Anti Neutrino uds dds

They don’t occur naturally n All of those particles except – Proton – Neutron – Electron • Don’t occur naturally an are unstable n So how do we make them? ? ?

How do we make them? n Particles traveling at nearly 300000 m/s – Nearly speed of light n Collide n Quarks Fly out n Recombine as new particles

How do we know this? CERN in Switzerland n Large Hadron Collider - 16 miles long n

The Large Hadron Collider n Particles accelerated by electromagnets – protons are steered in a circle by magnets. – Faster protons speed, more super conducting magnets required – Particles collided in the ATLAS Detector

What is ATLAS?

What is ATLAS? n n n The size of a five story building. Full of Detectors detecting different properties Located around collision a billion collision events per second twenty simultaneous telephone conversations by every person on the earth. 1 in 10 million collisions is interesting

Why is ATLAS so good? n Before: Bubble Chamber n After: Computer analysis for a billion 3 D collisions every second

How does it all work? ? The RGS Human Accelerator magnets n Protons n. A Detector

What’s The Point n 1900 - Marie Curie - Nuclear Radiation – Playing around in a shed • Cure for cancer • Could solve worlds energy crisis

Find Out More n http: //atlasexperiment. org/

Is this information useful? n For us - No n For the World - No n For the world in 100 years time - Probably n Satisfy our curiosity