what’s in an atom?. matter atom ~10 -10 mnucleus ~10 -15 mquarks

WHAT’S IN AN ATOM?

MATTER

Atom ~10-10m Nucleus ~10-15 m Quarks <10-18 m

MATTER

Atom ~10-10m Nucleus ~10-15 m Quarks <10-18 m

Fundamental Particles:ElectronQuarks: Up (u) & Down (d)

Force Carriers:Photon: carries EM forceGluon: binds quarks in nuclei

3 Generations of Matter:

Heavier

Same properties and interactions.

3 Generations of Matter:

Heavier

Same properties and interactions.

Felt only by Quarks

Force increases with distance – binds quarks into proton/neutrons

3 Generations of Matter:

Heavier

Same properties and interactions.

Affects only Quarks

Force increases with distance – binds quarks into proton/neutrons

Affects all particles

Responsible for nuclear/radioactive decay

Massive bosons?

3 Generations of Matter:

Heavier

Same properties and interactions.

Felt only by Quarks

Force increases with distance – binds quarks into proton/neutrons

Affects all particles

Responsible for nuclear/radioactive decay

Affects all charged particles

Causes lightning, magnetic fields

3 Generations of Matter:

Heavier

Same properties and interactions.

Felt only by Quarks

Force increases with distance – binds quarks into proton/neutrons

Affects all particles

Responsible for nuclear/radioactive decay

Massive bosons?

Affects all charged particles

Causes lightning, magnetic fields

Explains Chemistry???

Tiny effects on individual particles

Not included in the Standard Model

THE HIGGS BOSONOne particle predicted by the Standard Model has yet to be discovered: The HIGGS particle

THE HIGGS BOSONOne particle predicted by the Standard Model has yet to be discovered: The HIGGS particle

Needed to explain how the other particles gain masses

LEP at CERN excluded masses below 114 GeV

Must have a mass less than 1000 GeV for the model to be correct

Major motivation for building the LHC at CERN

THE HIGGS BOSONOne particle predicted by the Standard Model has yet to be discovered: The HIGGS particle

Needed to explain how the other particles gain masses

LEP at CERN excluded masses below 114 GeV

Must have a mass less than 1000 GeV for the model to be correct

Major motivation for building the LHC at CERN

WILL DISCOVER THE HIGGS PARTICLE OR, IF THE MODEL IS WRONG, SOMETHING ELSE !

UNANSWERED QUESTIONSWhy 3 generations?

Why 4 forces – can they be unified?

Many parameters, masses, etc. must be put in by hand

Difficult to keep the Higgs mass small

Dark Matter – what is it?

Gravity – how do we include it?

UNANSWERED QUESTIONSWhy 3 generations?

Why 4 forces – can they be unified?

Many parameters, masses, etc. must be put in by hand

Difficult to keep the Higgs mass small

Dark Matter – what is it?

Gravity – how do we include it?

Theorists have hypothesised many models to explain these, eg.

Supersymmetry – predicts a heavier partner for each particle in the SM

Extra dimensions – possibility of producing minute black holes that decay in the detector after 10-26s

Backups

The Standard Model

Lightest Heaviest

3 Generations of Particles