WHAT’S IN AN ATOM?. MATTER Atom ~10 -10 mNucleus ~10 -15 mQuarks
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Transcript of 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