1. Manfred Jeitler The Physics of LHC Baikal Physics School 2011 1 LHC/LEP SPS CMS ATLAS ALICE LHCb THE PHYSICS OF LHC Manfred Jeitler

2. Manfred Jeitler The Physics of LHC Baikal Physics School 2011 2 БАК (Большой Адронный Коллайдер)

3. Manfred Jeitler The Physics of LHC Baikal Physics School 2011 3 THE PHYSICS CASE

4. Manfred Jeitler The Physics of LHC Baikal Physics School 2011 4 aims of accelerators n energy frontier –find new particles –learn about basics of interactions »“unification” at higher energies: electroweak interactions, grand unification –cosmology: what the universe looked like soon after the Big Bang n intensity frontier –high-precision experiments

5. Manfred Jeitler The Physics of LHC Baikal Physics School 2011 5 Vom Urknall bis zum...?

6. Manfred Jeitler The Physics of LHC Baikal Physics School 2011 6 fermions (spin ½) charge 0 +2/3 -1/3 d u u d u d leptonsquarks the Standard Model +1 0 proton neutron baryons interactions strong weak gravitation ? weak W, Z electromagnetic  strong g force carriers = bosons (spin 1) e e     uct dsb

7. Manfred Jeitler The Physics of LHC Baikal Physics School 2011 7 completing the Standard Model: the W ± and Z 0 bosons (1983) CERN SPS

8. Manfred Jeitler The Physics of LHC Baikal Physics School 2011 8 completing the Standard Model: the top quark (1995) Tevatron (Fermilab, Chicago)

9. Manfred Jeitler The Physics of LHC Baikal Physics School 2011 9 fermions (spin ½) charge 0 +2/3 -1/3 leptonsquarks the Standard Model interactions strong weak gravitation ? weak W, Z electromagnetic  strong g e e     uct dsb Astro Accelerator

10. Manfred Jeitler The Physics of LHC Baikal Physics School 2011 10 The Higgs boson For the Standard Model to be consistent, there has to exist one more particle: the Higgs boson. It has not been found yet. However, many other high- precision measurement have confirmed the Standard Model in an impressive way.

11. Manfred Jeitler The Physics of LHC Baikal Physics School 2011 11 Peter Higgs in front of LHC-experiment ATLAS

12. Manfred Jeitler The Physics of LHC Baikal Physics School 2011 12

13. Manfred Jeitler The Physics of LHC Baikal Physics School 2011 13 the Standard Model works only with particles which are originally massless! mass is created through interaction with a (hypothetical) Higgs field due to spontaneous symmetry breaking this field is present everywhere in the universe “oscillations” in the Higgs field manifest themselves as Higgs particles, which should be observed at LHC / CERN over the next few years spontaneous symmetry breaking energy Higgs field hot universe (soon after big bang) cold universe (condensates in an asymmetric state with Higgs field) 0 v particles are massless particles acquire mass the Higgs boson

14. Manfred Jeitler The Physics of LHC Baikal Physics School 2011 14 The Higgs boson n cannot be lighter than 114.4 GeV/c2 – excluded by direct searches (LEP, “Large Electron-Positron collider, CERN) – some people thought they caught a glimpse of it at LEP (but then LEP was turned off) n should not be too heavy – else problems arise with the physics it’s supposed to explain n maybe “just around the corner” ? – not so good for LHC (“Large Hadron Collider”, CERN): hard to disentangle from background – have to study lots of possible decay channels ! – Fermilab (“Tevatron” collider, Chicago) has been trying hard to find it

15. Manfred Jeitler The Physics of LHC Baikal Physics School 2011 15 Supersymmetry (“SUSY”) n another 2 open problems in Standard Model: n “running coupling constants” of electromagnetic, weak and strong interactions meet almost but not completely at the same point n to avoid quadratic divergences in Higgs mass, “fine-tuning” is needed n both problems can be solved by introducing a symmetry between bosons and fermions

16. Manfred Jeitler The Physics of LHC Baikal Physics School 2011 16 bosons SUSY SUSY particles. green: known particles of the Standard Model red: hypothetical new particles for each known elementary particle there should exist a supersymmetric partner fermions Supersymmetry

17. Manfred Jeitler The Physics of LHC Baikal Physics School 2011 17 massive astrophysical cosmic halo objects? weakly interacting massive particles? questions of cosmology to particle physics: Why is there more matter than anti-matter in the universe? What is the universe made of? What is dark matter? What is dark energy?  answers to these questions concerning the largest scales might come from the physics of the smallest scales - elementary particle physics dark matter: MACHOS vs WIMPS

18. Manfred Jeitler The Physics of LHC Baikal Physics School 2011 18 experimental observation of SUSY particles ? Looking for these new supersymmetric particles was/is one of the most important tasks of the major experiments at the Tevatron in Chicago, USA, at the LHC at CERN (Geneva, Switzerland) and at the planned e + e - linear collider. SUSY particles may show very clear signatures due to cascade decays

19. Manfred Jeitler The Physics of LHC Baikal Physics School 2011 19 important questions of today’s particle physics (ongoing experiments) Where do particles get their mass from? (by interaction with the Higgs particle?) Why are these masses so different? Is there an overall (hidden) symmetry such as supersymmetry (SUSY)  “mirror world” of all known particles?. What is the nature of “dark matter” and “dark energy” in the universe? Why is there more matter than anti-matter? Why have neutrinos such small mass? Is there a Grand Unification which combines all interactions, including gravitation? Are there extra dimensions, D > 4 ? (  string theory, …)

20. Manfred Jeitler The Physics of LHC Baikal Physics School 2011 20 ACCELERATORS

21. Manfred Jeitler The Physics of LHC Baikal Physics School 2011 21 21 Cockroft-Walton accelerator at CERN

22. Manfred Jeitler The Physics of LHC Baikal Physics School 2011 22 inside of an Alvarez-type accelerating structure

23. Manfred Jeitler The Physics of LHC Baikal Physics School 2011 23 Synchrotron elements of a synchrotron quadrupole magnet: focussing dipole magnet: to keep particles on track high-frequency accelerating cavity

24. Manfred Jeitler The Physics of LHC Baikal Physics School 2011 24 24 SPS Tunnel Super-Proton-Synchrotron (Geneva)

25. Manfred Jeitler The Physics of LHC Baikal Physics School 2011 25

26. Manfred Jeitler The Physics of LHC Baikal Physics School 2011 26 Professor BaikalixProfessor Cernix Astroparticles with 10 19 eV !! Collisions at 7 TeV !! Summer student in Bolshie Koty

27. Manfred Jeitler The Physics of LHC Baikal Physics School 2011 27 quadrupole dipole resonator reaction products interaction zone layout of a circular collider

28. Manfred Jeitler The Physics of LHC Baikal Physics School 2011 28 first electron-electron collider: Novosibirsk / Russia VEP-1 130+130 MeV

29. Manfred Jeitler The Physics of LHC Baikal Physics School 2011 29 superconducting RF cavity from LEP

30. Manfred Jeitler The Physics of LHC Baikal Physics School 2011 30 electrons vs. protons +30 MinBias

31. Manfred Jeitler The Physics of LHC Baikal Physics School 2011 31 n electrons (or other leptons): elementary –no substructure –few tracks –sharp energy n protons (hadrons): compounds made up of quarks –what collides is one quark or gluon with another quark or gluon –lots of other “spectators” »mess up the picture –never know collision energy of interacting constituents »only maximum elementary particle or not?

32. Manfred Jeitler The Physics of LHC Baikal Physics School 2011 32 n scales with 4 th power of Lorentz factor n energy loss per turn: n or synchrotron radiation

33. Manfred Jeitler The Physics of LHC Baikal Physics School 2011 33 velocity

34. Manfred Jeitler The Physics of LHC Baikal Physics School 2011 34 n to lose less energy you may –make particles heavier (4 th power!) –make accelerator bigger (only linear) n electron synchrotron with same losses as LHC : –LHC circumference: 27 km n 27 * 2000 4 ~ 4 * 10 14 km ~ 40 lightyears synchrotron radiation

35. Manfred Jeitler The Physics of LHC Baikal Physics School 2011 35 35

36. Manfred Jeitler The Physics of LHC Baikal Physics School 2011 36 Collisions at the TeV scale

37. Manfred Jeitler The Physics of LHC Baikal Physics School 2011 37 LHCILC e – e +  Z H Z  e – e +, H  b b … Example: simulated Higgs event –

38. Manfred Jeitler The Physics of LHC Baikal Physics School 2011 38 n electron colliders: accelerating RF-cavities to make up for synchrotron losses n proton colliders: dipole magnets to keep protons on a circular track –conventional (“warm”) magnets: ohmic losses –superconducting magnets: cryogenics »LHC cryogenics: ~30 MW out of total of 180 MW for all of CERN –“there is no such thing as a free lunch” what do you spend your money on (electricity bill)?

39. Manfred Jeitler The Physics of LHC Baikal Physics School 2011 39 n proton colliders are “discovery” machines –proton-antiproton or proton-proton –SPS: W, Z bosons »Super Proton Synchrotron, CERN –Tevatron: top quark »Fermilab, Chicago –LHC, CERN: ??? »Large Hadron Collider n electron-positron colliders allow for precision measurements –LEP: precision measurments of Z mass »Large Electron-Positron Collider, CERN “discovery” vs. “precision” machine

40. Manfred Jeitler The Physics of LHC Baikal Physics School 2011 40 question (homework) n a text in a Cern exhibition states: “the force of the LHC beam is comparable to that of a herd of running elephants” n is this correct? help: n what could be meant by “force”? –momentum? –kinetic energy? n remember the energy and number of particles in LHC –3.5 TeV, 10 11 protons per bunch, ~3000 bunches n how heavy and fast is an elephant? –which kind? Indian / African / Siberian?

41. Manfred Jeitler The Physics of LHC Baikal Physics School 2011 41 another question (more homework) n another text says: “the energy of a particle in LHC is the same as that of a flying mosquito” n is this correct? n is there a contradiction to the statement about elephants? help: n how heavy and fast is a mosquito? –Siberian mosquito compared to Indian elephant

42. Manfred Jeitler The Physics of LHC Baikal Physics School 2011 42 yet another question (still more homework) n the frequency of the LHC clock at “flat top” (3.5 TeV) is roughly 40 MHz n does the clock frequency at injection (450 GeV) have to be different? –why? n if yes, what is the change of clock frequency during the “ramp” ? –acceleration period, when particle energy and magnetic field rise n could this be a problem?