1. Vincent Hedberg - Lund University1 LHC & ATLAS The largest particle physics experiment in the world

2. Vincent Hedberg - Lund University 2 CERN – A laboratory for the world There were 12 member states in the beginning. CERN was founded in 1954

3. Vincent Hedberg - Lund University 3 The 20 member countries OBSERVERS: UNESCO EU Israel Turkey SPECIAL OBSERVERS (for the LHC): USA Japan Russia India

4. Vincent Hedberg - Lund University 4 4 CERN in numbers  The CERN budget is about 1 billion AUD.  Half of the budget is used to pay the salaries for the 2500 employees.  The cost of the LHC accelerator has been about 5 billion AUD.  CERN is responsible for the accelerators.  The 560 universities and institutes that do research at CERN are responsible for the experiments.  In total, 9000 physicists from all over the world are doing research at CERN.

5. Vincent Hedberg - Lund University 55 Particle physics  The study of the fundamental building blocks of nature and their interactions.  Small = High Energy

6. 6 Vincent Hedberg - Lunds Universitet 6 The building blocks ~1 m ~10 -10 m~10 -14 m~10 -18 m We now know that the smallest constituents of matter are three generations of quarks and leptons.

7. Vincent Hedberg - Lund University 7 GRAVITY GRAVITY Force carrier: The Graviton Make things fall to the ground. Make planets go around the sun. THE ELECTROMAGNETIC FORCE THE ELECTROMAGNETIC FORCE Force carrier: The Photon Keep electrons in the atoms. Electricity, light, radiowaves …. The forces in nature THE STRONG FORCE THE STRONG FORCE Force carrier: The Gluon Make protons and neutrons stick together. Make quarks stick together. THE WEAK FORCE THE WEAK FORCE Force carrier: The W & Z Cause some radioactive decays. Important for the processes in the sun. Nucleus Proton

8. 8 Vincent Hedberg - Lund University 8 The Large Hadron Collider (LHC)  The 27 km long Large Hadron Collider accelerates protons to 99,999999991% of the speed of light.  In four places the proton beams are made to collide and the collisions are studied by experiments. There are up to one billion collisions per second.  The stored energy in one beam is 360 MJ. ( 360MJ ~ energy of a train travelling at 150 km/h or of an explosion of 77 kg of TNT).

9. 9 Vincent Hedberg - Lund University 9 In the LHC accelerator tunnel

10. Vincent Hedberg - Lund University 10 The magnets that bend the proton beams. Magnetic field: 8.3 Tesla 1232 dipole magnets 15 m long 35 ton heavy 120 tonnes of liquid helium (1.9 K) Current: 11800 Ampere

11. Vincent Hedberg - Lund University 11 The building of the LHC

12. Vincent Hedberg - Lund University 12 10 September 2008 – Champagne !

13. Vincent Hedberg - Lund University 13 19 September 2008 – Hangover ! A shortcut burned a hole in the helium enclosure and a pressure wave damaged about 50 magnets. Several tonnes of liquid helium leaked out.

14. Vincent Hedberg - Lund University 14 Same procedure as last year ! So far no explosions….. And a new world record in collision energy ( 7 TeV). However, only half of the designed collision energy in 2010 and a collision rate (luminosity) that is 17,000 times lower than the design target. First collisions in ATLAS on the 23rd of November 2009.

15. Vincent Hedberg - Lund University 15 Experiments at the LHC ATLAS CMS LHCb ALICE CERN Experiments ATLAS: Proton-proton collisions CMS: Proton-proton collisions ALICE: Atom-atom collisions LHCb: Proton-proton collisions giving b quarks CERN

16. 16 Vincent Hedberg - Lund University 16 Detection of particles Tracking Detector Electromagnetic calorimeter Hadronic calorimeter Muon Detector Photons Electrons Muons Protons Pions Neutrons Inner layer Outer layer

17. Vincent Hedberg - Lund University 17 The ATLAS experiment The ATLAS Experiment Size: 44 by 22 m Weight: 6000 tonnes The collaboration 2900 physicists (173 Univ., 37 Countries) (Melbourne & Sydney)  Muon detector  Hadron calorimeter  Electromagnetic calorimeter  Tracking detector

18. Vincent Hedberg - Lund University 18 Vincent Hedberg - Lund University 18 ATLAS in the movies 18

19. Vincent Hedberg - Lund University 19 A simulated collision in ATLAS LHC Proton bunch LHC Proton bunch

20. 20 Vincent Hedberg - Lund University 20 A real collision in ATLAS

21. 21 Vincent Hedberg - Lund University 21 Physics studies: The Higgs particle H ZZ e+e- ++ -- p p Short lifetime Long lifetime

22. Vincent Hedberg - Lund University 22 Black Hole Signature: Many particles and particles with a high energy and with a large angle with respect to the proton direction. The holes will disappear after 10 -26 s according to the theory (if they are produced). Physics studies: Black holes

23. Vincent Hedberg - Lund University 23 Black holes = The end of the world ? Energy spectrum Cosmic radiation LHC There are protons in the cosmic radiations with a higher energy than what can be produced by LHC. The number of collisions at LHC during one year corresponds to about 1000-10,000 years of collisions in the atmosphere.

24. Vincent Hedberg - Lund University 24  The rotational speed of stars in some galaxies are too high to be explained by the known matter.  This unknown matter could consist of new particles that can be discovered in ATLAS. Dark Matter Dark Energy The universe is not expanding with a constant speed. It seems that there is an unknown repulsive force between the galaxies. This force is thought to be caused by a mysterious dark energy. What other problems remain to be solved ?

25. Vincent Hedberg - Lund University 25  What is dark energy ?  What is dark matter?  What happened with the anti-matter ?  How does particles obtain their mass ? (Higgs ?)  Why is the gravitation so weak ? (Extra dimensions ? Black holes ?)  Are the different forces the same thing ? LHC can perhaps give the answer What problems remain to be solved ?

26. Vincent Hedberg - Lund University 26 Spin off technology …. oComputer technology oThe World Wide Web oThe Computer Grid oDetector technology oRadiation treatments oMedical instrumentation oNuclear waste disposal oTransmutation oSuperconducting magnets oElectronics o......

27. Vincent Hedberg - Lund University 27 The World Wide Web The worlds first web-server.Tim Berners-Lee, the inventor of the World Wide Web. The most important spin-off from particle physics is the World Wide Web. It was invented at CERN as a way for physicists to share information on computers in different countries.

28. Vincent Hedberg - Lund University 28 The next large computer project is the grid. The Worldwide LHC Computing Grid has been developed in order for physicist around the world to have sufficient computer power and in order for them to get hold of the 15 million Gigabytes of data that the LHC will produce each year.

29. Vincent Hedberg - Lund University 29 Vincent Hedberg - Lund University 29 Finally, the most common question… All this sounds very complicated and expensive, but what is the purpose of the whole thing ? Of what practical use is this research ? There are two main answers to this question: 1.Michael Faraday in 1830 to Queen Victoria: Madam, of what use is a baby (30 years later: Maxwell, 70 years later: Marconi) 2. We will (probably) never have any practical use of this basic research ! The main purpose is to understand the world we live in in the same way as the pictures from the Hubble telescope give us new knowledge that has no practical applications. The Sombrero galaxy (Hubble telescope)