1. ATLAS physics – an introduction Alan Barr, University of Oxford

3. Where do the particles get their mass from? Where has all the anti-matter gone? What is dark matter made of? What else is out there?

4. The Standard Model

5. 22nd June 2011LHC physics Forces Matter particles Masses & potentials (Untested)

7. ATLAS Segment of detector

9. P The reconstruction of an early collision event

11. Higgs production and decays…

13. How many collisions? Cross section for Higgs ~ 20 pb Cross section for inelastic pp collision ~ 20 mb Data taken before discovery ~13 fb -1

15. A collision producing 2 high-energy photons Higgs   +  ?

16. Higgs  2 photons Bump at mass of new particle

17. What we know about the new particle Mass close to 125 GeV Spin = 0 Couples to Fermions Couples to Bosons Couples according to Mass? so is a Higgs Boson

18. Couplings

20. Except…

21. Symmetries of nature Gauge symmetry (EM, Strong, Weak forces) Space-time symmetry See: http://www.superstringtheory.com/experm/exper4a.htmlhttp://www.superstringtheory.com/experm/exper4a.html

22. Extended higgs sector 2 cplx doublets  8-3 = 5 Higgs bosons! (S)Particles Standard Model Supersymmetric partners quarks (L&R) leptons (L&R) neutrinos (L&?) squarks (L&R) sleptons (L&R) sneutrinos (L&?)  Z 0 W ± gluon BW0BW0 h0H0A0H±h0H0A0H± H0H±H0H± 4 x neutralino 2 x chargino After Mixing gluino Spin-1/2 Spin-1 Spin-0 Spin-1/2 Spin-0 Bino Wino 0 Wino ± gluino ~ ~ (Higgsinos)

24. The Standard Model