Charters School Peter Kalmus March 2006 Professor Peter Kalmus Particles and the Universe Physics Department

Charters School Peter Kalmus March 2006

Professor Peter Kalmus

Particles and the Universe

Physics Department


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


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 1018

Time sinceBig Bang / s

LHC

Hot as Hell445oC = Boiling point of Brimstone


Primordial Soup CERN style 100 GeV / particle

Ingredients

56% 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


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


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)


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 !



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



Dis

tanc

e

(Mag

nitu

de)

Hubble Diagram (simplified)

Recent results show that expansion is accelerating !

Cosmic repulsion !“Dark energy”


Structure of the Atom

Atom

~ 10-10m

Nucleus

Early 20th Century electron, nucleus

electric forceelectromagnetism

1930s

bunch ofgrapes

Proton +

Neutron

strongforcetown

~ 10-15m


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


Today’s building blocks

Leptons(do not feel strong force)

electron e- -1

e-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


Today’s building blocks

Leptons(do not feel strong force)

electron e- -1

e-neutrino e 0

Quarks(feel strong force)

up u +2/3

down d -1/3

muon -1

-neutrino 0

tau -1

-neutrino 0

charm c +2/3

strange s -1/3

top t +2/3

bottom 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


Earth, Moon, X

Solar system X

Antistars in our Galaxy ?

Other (anti-) galaxies ?

Telescopes X

Cosmic rays ?

AMS (Space station)

AntimatterAnti-hydrogen : made in lab

Bulk antimatter ? Where ?

Difficult to detect

Annihilation ofAntigalaxy ?

Signal ?

e+ + e - +

0.511 MeV -ray “line” Alfven hypothesis

Radiation pressure


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 !


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 !


AcceleratorExtractbeam

Injector

Vacuum ring

RF cavitieselectric kick

~Bendingelectro-magnet

Focusingelectro-magnet


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


Forces by exchange

Analogy onlyUseful mental picture ?


Attraction


Unification of the fundamentalforces of nature

Electricity Magnetism Apples Planets

Electro-magnetic

Gravity

Faraday, Maxwell Newton


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 ?


Collider Injectanti-protons

Injectprotons

Collide 2 beamsInside vacuum

RF cavitieselectric kick

~Bendingelectro-magnet

Focusingelectro-magnet

Carlo RubbiaAntiprotons

Simon van der MeerStochastic cooling


UA1 ExperimentMuon

Neutrino

Electromagcalorimeter

Hadron calorim.and magnet

Proton Antiproton

Hadron

Electron

Wire

chamber

Vacuumpipe

Muon chambers



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


From

THE PRIME MINISTER10 Downing StreetTo

Professor 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


W and Z particles discoveredUA1 Collaboration at CERN

Included following members of Queen Mary

Peter 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 confirmed

Nature’s fundamental forcesreduced from 4 to 3

Nobel Prizes


[email protected]://www.ph.qmul.ac.uk

THE END

Documents

Charters School Peter Kalmus March 2006 Professor Peter Kalmus Particles and the Universe Physics Department