34
s School Peter Kalmus March 2006 Professor Peter Kalmus articles and the Universe Physics Department
Charters School Peter Kalmus March 2006
Professor Peter Kalmus
Particles and the Universe
Physics Department
Charters School Peter Kalmus March 2006
Supernova 1987A Neutrino numbers
Emitted ~ 1058
Hit Earth ~ 1029
Hit tank ~ 1017
Interact ~ 10SN
1987A Earth
170,000light years
Energy release ~ 1046 J
SN~ 1046 J
10,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000
8 arc min
Large Magellanic Cloud
Sanduleak - 69o 202
Charters School Peter Kalmus March 2006
1016 1 TeV
1013 1 GeV
1010 1 MeV
107 1 keV
104 1 eV
10 1 meV
T/K Energy
ParticleEra
NuclearEra
AtomicEra
PrimordialSoup
Sun forms
Todayps ns s ms s
1 day
1 year
Time
Era ofAstronomy
TevatronLEP
History of theUniverse
10-12 10-6 100 1013 1018Time sinceBig Bang / s
LHC
Hot as Hell445oC = Boiling point of Brimstone
Charters School Peter Kalmus March 2006
Primordial Soup CERN style 100 GeV / particle
Ingredients56% quarks16% gluons 9% charged leptons 9% W & Z particles 5% neutrinos 2% photons 2% gravitons 1% Higgs bosonsRecipe by Rocky Kolb
Hot 3 x 1015KCondensed
Missingingredients
Dark matterDark energy
Charters School Peter Kalmus March 2006
Sun
Inverse square law
a
Rotation in spiral galaxiesStars move too fast(measured by Doppler shift)
96 % of universe is undetected~4% Baryonic; ~24% “Dark Matter”~72% “Dark Energy”
Kepler, Newton
T2 = 4 2 a3 /G Mo
v2 = G Mo/a (circular orbit)
Mo
v
Charters School Peter Kalmus March 2006
Expect from detected stars etc.
Measured velocities from Doppler shifts
Galaxy rotation curve
Hence there is more gravitationally attractive material than has been detected Dark matter
Distance from centre
velo
city
Dark energy
Slowest v
2 v
3 v
Fastest 4 v
After some time the fastest particles will be furthest away
Explosion in empty space (forget about gravity)
Charters School Peter Kalmus March 2006
Recession velocity (Doppler Redshift z)
Dis
tanc
e (
Mag
nitu
de)
Hubble Diagram
Plot distance againstrecession velocity for many galaxies Get straight line Big Bang
nearest galaxy
furthest galaxyhighest recession velocity
The Universe is like this !
Charters School Peter Kalmus March 2006
Recession velocity (Doppler Redshift z)
Dis
tanc
e (
Mag
nitu
de)
Hubble Diagram But cannot ignore gravity which slows down the flow
Expect this line to curve downwards for very distant galaxies. Expansion would decelerate
Charters School Peter Kalmus March 2006
Recession velocity (Doppler Redshift z)
Dis
tanc
e (
Mag
nitu
de)
Hubble Diagram (simplified)
Recent results show that expansion is accelerating !
Cosmic repulsion !“Dark energy”
Charters School Peter Kalmus March 2006
Structure of the Atom
Atom
~ 10-10m
Nucleus
Early 20th Century electron, nucleus
electric forceelectromagnetism
1930s
bunch ofgrapes
Proton +Neutron
strongforcetown
~ 10-15m
Charters School Peter Kalmus March 2006
Neutrinos
Antiparticles
1950s, 1960s
> 200 new “elementary” (?) particles
Feel weak force“predicted” later discovered 100,000,000,000,000 per second pass through each person from the Sun
Equal and opposite properties “predicted” later discoveredAnnihilate with normal particlesNow used in PET scans
Many new particles created in high energy collisions
Convert energy to mass. Einstein E = mc2
Charters School Peter Kalmus March 2006
Today’s building blocks
Leptons(do not feel strong force)
electron e- -1e-neutrino e 0
Quarks(feel strong force)
up u +2/3down d -1/3
proton = u u d+2/3 +2/3 -1/3 = +1
neutron = u d d+2/3 -1/3 -1/3 = 0
4 particles very simple
multiply by 3 (generations)multiply by 2 (antiparticles)
First generation
Charters School Peter Kalmus March 2006
Today’s building blocks
Leptons(do not feel strong force)
electron e- -1e-neutrino e 0
Quarks(feel strong force)
up u +2/3down d -1/3
muon -1
-neutrino 0
tau -1
-neutrino 0
charm c +2/3strange s -1/3
top t +2/3bottom b -1/3
Also antileptonsantiquarks
6 leptons6 antileptons
6 quarks6 antiquarks
baryons q q q
antibary. q q q
mesons q q
Recent news:pentaquarks
Charters School Peter Kalmus March 2006
Earth, Moon, X Solar system XAntistars in our Galaxy ?Other (anti-) galaxies ?
Telescopes XCosmic rays ?AMS (Space station)
AntimatterAnti-hydrogen : made in labBulk antimatter ? Where ?Difficult to detect
Annihilation ofAntigalaxy ?
Signal ?
e+ + e - + 0.511 MeV -ray “line” Alfven hypothesis
Radiation pressure
Charters School Peter Kalmus March 2006
Constituents How can we find internal structure?
Insect 1 lens2 lenses3 lenses
: Magnifying glass: Microscope : No improvement
Resolution limited by wavelength of light =
Visible light wavelength ~ 5 x 10-7 mThis is 5,000 times size of atom500 million times size of nucleus
To “probe” elementary particles need wavelengths lower by factor more than a billion !
Charters School Peter Kalmus March 2006
Quantum physics to the rescue
hp
Planckconstant
momentumwavelength
Particles have wave properties
“See” small objects small wavelength high momentum high energy large accelerator
Non-relativistic p = m vmass x velocity
Relativistic p = m v = 1/ (1 - v2/c2)1/2
To observe the smallest objects we need the largest machines !
Charters School Peter Kalmus March 2006
AcceleratorExtractbeam
Injector
Vacuum ring
RF cavitieselectric kick
~Bendingelectro-magnet
Focusingelectro-magnet
Charters School Peter Kalmus March 2006
Forces
Gravity
falling objectsplanet orbitsstarsgalaxies
inversesquare law
graviton
inversesquare law
photon
shortrange
W±, Z0
Electro-magnetic
atomsmoleculesopticselectronicstelecom.
Weak
betadecay
solarfusion
Strong
nuclei
particles
shortrange
gluon
Charters School Peter Kalmus March 2006
Forces by exchange
Analogy onlyUseful mental picture ?
Charters School Peter Kalmus March 2006
Attraction
Charters School Peter Kalmus March 2006
Unification of the fundamentalforces of nature
Electricity Magnetism Apples Planets
Electro-magnetic
Gravity
Faraday, Maxwell Newton
Charters School Peter Kalmus March 2006
Unification of the fundamentalforces of nature
Electricity Magnetism Apples Planets
Electro-magnetic
Weak Strong Gravity
Faraday, Maxwell Newton
Electroweakunified force
Salam, Weinberg, Glashow
, W +, W -, Z 0 0 80 80 90 GeV
Do the W and Z particles really exist ?
Charters School Peter Kalmus March 2006
Collider Injectanti-protons
Injectprotons
Collide 2 beamsInside vacuum
RF cavitieselectric kick
~Bendingelectro-magnet
Focusingelectro-magnet
Carlo RubbiaAntiprotons
Simon van der MeerStochastic cooling
Charters School Peter Kalmus March 2006
UA1 Experiment Muon
Neutrino
Electromagcalorimeter
Hadron calorim.and magnet
Proton Antiproton
Hadron
Electron
Wire
chamber
Vacuumpipe
Muon chambers
Charters School Peter Kalmus March 2006
Charters School Peter Kalmus March 2006
Carriers of Weak ForceFound at CERNThe W boson the hypo
carries the weak force whichcontrols the production ofenergy in the Sun and some
The Discovery of the W Boson
The observation of the W intermediate vector boson, the particle that
carries the weak nuclear force, is the most outstanding achievement
of the CERN laboratory in Geneva and one of the most important
advances in physics of this century. It is the successful conclusion of
The Role of UK ScientistsTwenty-five British scientists played an important part inthe remarkable discovery of the W boson. They were ledby Professor J D Dowell of Birmingham University,Professor P I P Kalmus of Queen Mary College and Dr AAstbury of Rutherford Appleton Laboratory. The W boson
Charters School Peter Kalmus March 2006
FromTHE PRIME MINISTER10 Downing StreetToProfessor P. I. P. Kalmus
It is very encouraging that so many British scientists were in the team that discovered the “W boson”, and I would like to congratulate you and your colleagues from Queen Mary College on your success. I am sure that British physicists will be among the first to unify all the four basic forces
Charters School Peter Kalmus March 2006
W and Z particles discoveredUA1 Collaboration at CERNIncluded following members of Queen MaryPeter KalmusAlan Honma
Eric EisenhandlerRichard Keeler
Reg GibsonGiordi Salvi
Graham ThompsonThemis Bowcock
Results confirmed by another CERN collaboration,and few years later at Fermilab USA
Electroweak unification confirmedNature’s fundamental forcesreduced from 4 to 3Nobel Prizes
