Download - Particle Physics : Now and the Future
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Particle Physics : Now and the Future
David MilsteadStockholms Universitet
The most important questions in modern physics
The most important experiment in modern physics
Physics as a career
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Open questions for the curious physicist
What are the fundamental building blocksof matter and what are the forces whichact on them ?
Why do particles have masses ?
Why does nature seem to dislike anti-matter ?
What is dark matter and dark energy ?
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Nature’s building blocks (so far)
proton
W,Z,g, force
Standard Model of Particle Physics
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Forces between particles
e- e-
e+e-
q q
Z
g
Looking for a single super force !
Electromagnetism
Weak
Strong
Gravity ?
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Anti-matter is rare (<<1%). Why ?
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How do particles get mass ?
t
bcs
ude
e
Massa
Peter Higgs theory explains why particles get mass.
To prove the theory we must find a new particle: Higgs boson
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Energy in the Universe
Atoms
Dark matter 25% Dark energy
70%
We can’t understand 95% of the energyin the universe
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Supersymmetry
A new family of particles
Predicted to appear at the LHCOne of them could be dark matter
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Story so far• Protons are made up of quarks.
What are quarks made up of ?• Are there more quarks ?• Can we find a single super force ?• We can’t understand 95% of the
universe’s energy – what is dark matter?
• Where did the anti-matter go ?
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Go back to the start
First mammalsFirst DNA
Nu (15 billion years)Solar system
10-36 10-6 10-2
Matter-antimatter asymmetry
The electromagnetic weak forces separate, Higgs
Quarks become bound in protons
sekunder
Big bang
+ dark matter, dark energy.
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microscope
Accelerator Naked eye
binoculars
Telescope
Measuring large and small objects
Accelerators collide high energy particles to recreate the early universe and look inside a proton!
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Collide a particle with a proton and study quarks
We can also produce newparticles via E=mc2 -Higgs, SUSY etc..... The second most useful
relation in physics
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LHCLarge Hadron Collider collides protons with energy 7 TeVIt starts in 2007
Each proton beam has energy = aircraft carrier at 10 knots
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LHC vs Stockholm’s underground
LHC Blue line
Length 27km 16 km
Depth 100m 20-30m
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ATLAS experiment
Five levels high7,000,000 kg 42m length 22m wide 22m high2,000 physicists 150 universities 34 countriesThe goal is to discover new particles!
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How can we find the Higgs
boson/SUSY ?
We are developing the WWWs successor: the Grid
Concorde(15 Km)
Balloon(30 Km)
CD stack with1 year LHC data!(~ 20 Km)
Mt. Blanc(4.8 Km)
Search through 20,000,000 collisions for one Higgs boson or several SUSY particles
LHCs data corresponds to 14 million cds every year We will need 100,000 computers to analyse the data
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We start with this
And look for this signature in the mess
Finding the Higgs boson
• 800,000,000 proton-proton interactions per second
• ~100,000,000 channels
• 0.0002 Higgs per second
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Nature’s mirror doesn’t work
Process B is a mirror image of process A. Process B uses the anti-particles of process A.
We can measure a difference between them.Could explain why the early universe lost its anti-matter!
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Summary of the physics LHC is one of the world’s most ambitious
scientific projects
It will address many of the most important questions in modern physics
- What is mass ? - Matter anti-matter - Dark matter + much more.. Particle physics looks forward to a bright future
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Research Physics as a career
• 3-4 years undergraduate (BSc/MSc) + 3-4 post-graduate (Ph.D.)
• 2:2 upwards required• Be prepared to travel• Be prepared for several short term post-
doctoral jobs• Can jump off at any point to a far more
lucrative career
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The best and worst aspects of my job
Cutting edge physicsTravel, new languages and culturesFree to do what I find interestingNobody asks what I’m doing
Applying for new grants/fundingTravel – impossible to stay put for a monthNobody asks what I’m doing