The LHC: Search for Elementary Building Blocks in Nature

Niels Tuning (Nikhef) 13 Nov 2012

Particle Physics

Study Nature at distances < 10-15 m

atom nucleus

Quantum theory describes measurements down to 10-18 m

(Compare: 10+18 m = 100 lightyears)

10-15 m

Powers of ten…

Universe 1026 m

Galaxy1021 m

Solar system 1013 m

Earth107 m

Spider10-2 m

Atom 10-10 m

Nucleus10-15 m

Collisions10-18 m

Particle Physics

Questions that were asked for over 2000 years… What are the elementary building blocks of matter? What are the forces that act on matter ?

Demokritosatom

Newtonforces

Maxwellelectromagnetism

EinsteinAll…

400 400 v.Chr.v.Chr. 16871687 18641864 19051905

Why fundamental research?

Fundamental research

– Can lead to surprises,

• Sometimes even useful…

“Without general relativity, the GPS would be wrong by 10km/day !”

Why fundamental research?

Fundamental research

– Leads to useful spin-off

• Medical

• Internet

• Educating scientists for society

(Philips, ASML, etc, etc)

PET scan www

Our knowledge in 2012

http:// pdg.lbl.gov

up

down

electron

Elementary particles

Proton

up

up

down

Neutrondown

down

up

What can you make out of 3 building blocks?

periodiek systeemvan Mendeleev

Everything!Everything!

Elementary particlesq

uark

s

Not 1 generation, but 3!

lepto

ns

(1956)

u

d

I

e

e

(1895)

t

b

III

(1973)

(2000)

(1978)

(1995)

c

s

II

(1936)

(1963)

(1947)

(1976)

•Fundamentele deeltjes en deeltjesversnellers

Is this everything?

Charge

+2/3 e

-1/3 e

-1 e

0 e

quark

s

Generation:

lepto

ns

Matter

(1956)

u

d

I

e

e

(1895)

t

b

III

(1973)

(2000)

(1978)

(1995)

c

s

II

(1936)

(1963)

(1947)

(1976)

Anti-matter

Revolutions early 1900:– Theory of relativity

– Quantum Mechanics

Paul Dirac (1928): relativistic quantum theory!

For every matter particle there is an anti-matter particle!

Anti-matter particle:• Same mass• Opposite electric

charge

Elementary particles

Charge

+2/3 e

-1/3 e

-1 e

0 e

quark

sle

pto

ns

Matter

(1956)

u

d

I

e

e

(1895)

t

b

III

(1973)

(2000)

(1978)

(1995)

c

s

II

(1936)

(1963)

(1947)

(1976)

Elementary particles

-2/3 e

+1/3 e

+1 e

0 e

u

d

c

s

t

b

e

e

Anti-matter

Lading IIII IILading

+2/3 e

-1/3 e

-1 e

0 e

quark

sle

pto

ns

Materie

(1956)

u

d

I

e

e

(1895)

t

b

III

(1973)

(2000)

(1978)

(1995)

c

s

II

(1936)

(1963)

(1947)

(1976)

How do you make anti-matter??

e+ e-

Albert Einstein: E=mc2

Matter + anti-matter= light !

(and vice versa)

e+ e-

Anti-matter in hospitals:the PET-scan

ee++ee

What are the big questions?

I. What are the big questions? “Anti-matter”

Where did the anti-matter disappear?

No anti-matter found with satellites

No anti-matter galaxies

II. What are the big questions? “Higgs”

Mass of particlesNeutrino’s

Electron

Muon

Tau

up,down, strange

Top quark

bottom

charm

The Higgs boson:provides the ‘formula’ to give particles mass!

Amazing prediction:

We only studied 4% of the universe!

Temperature fluctuationsstructure formation of galaxies

Rotation-curves Gravitational lens

What isdark materie ?

III. What are the big questions? “Dark matter”

What are the big questions?

Anti-matter??(where did it go??)

Dark matter??(what clustered the galaxies??)

Higgs??(what makes particles heavy?)

•Waar is de Anti-materie heen?

AstronomyAstronomy ParticleParticle

PhysicsPhysics

FundamentalFundamental(curiosity driven)(curiosity driven)

researchresearch

The biggest microscope on earththe Large Hadron Collider (LHC)

at CERN in Genève

The LHC accelerator

Geneve

The Large Hadron Collider

Geneve Amsterdam

LHC: 27 km A10: 32 km

The LHC machine

Energy is limited by power of 1232 dipole magnets: B= 8.4 TEnergy is limited by power of 1232 dipole magnets: B= 8.4 T

40 million collisions per second

Beam 1

Beam 2

25 ns = 7.5 m

100.000.000.000 protonen

Classical collisions

Quantum mechanical collissionsproton proton

•Niels Tuning Open Dag 2008

Colliding protons

What do we expect?

Since 30 years there are very precise predictions!

Our language

Standaard Model Lagrangiaan Bladmuziek (J.S. Bach)

SU(2)L U(1)Y SU(3)C

At the LHC at Cern:

1) Transform energy into matter Create new particles!

How do we discover new particles?

At the LHC at Cern:

1) Transform energy into matter 2) New particles change accurate predictions

How do we discover new particles?

ATLAS

LHCb

ALICECMS

ATLAS

LHCb

1) Transform energy into matter

2) New particles change accurate predictions

23 sep 2010 19:49:24Run 79646 Event 143858637

The LHCb DetectorThe LHCb Detector

LHCb: study B decays1) Find differences between matter and anti-matter

2) Find new particles

b

s

s

b

b s

μ

μ

LHCb: study B decays

2) Find new particles

b s

μ

μ

B0s→μμ

B0s→μμ?

LHCb: study B decays

b s

μ

μ

B0s→μμ!

Only 3 out of 109 B particles decay to two muons

Prefect prediction!

Do new particles exist?

ATLAS: What does a collision look like ?

proton

proton

quark

neutrino

elektron

quark quark

quark

Simulation top quark production

human

Biggest camera on earth

energy electrons and photons

energy of “quarks”

position and momentum of charged particles

magnetmuon detector

magnet

80 MegaPixel camera 40.000.000 foto’s per seconde

The Atlas pixel detector

The Atlas Muon Detector

mens

NikhefCERN

Down stairs in the Nikhef hal

Normal

How is a discovery made?

New ?

?

muon

muon

muon

muon

proton proton

How many Higgs bosons were produced at the LHC up to now

0

If the Higgs does not exist

proton proton

How many Higgs bosons were produced at the LHC up to now

If the Higgs does exist

mh = 120 GeV: 120.000

mh = 200 GeV: 60.000

Higgs ZZ 4 muonsvery few…Higgs ZZ 4 muonsvery few…

120.000 Higgs bosons

• Only 1 in 1000 Higgs bosons decays to 4 muons

• 50% chance that ATLAS detector detects them

60 Higgs 4 lepton events

higgs

Z

Z

hZZ l+l-l+l-

l+

l-

l-

l-

peak !?

peak!

Higgs Higgs 2 photons 2 photons

higgs

foton

foton

hγγ verval

Presentation CMS en ATLAS experiment: Higgs boson discovery4th July 2012

What is dark matter?

Where did the anti-matter disappear?

What makes particles heavy?

Big questions

Niels.Tuning@nikhef.nl

Search for elementary building blocks of Nature

END