1. Why LHC? Tara Shears, University of Liverpool

2. To understand the universe … Fundamental particles atoms stars and galaxies NOW Investigate with astrophysics, using telescopes BIG BANG Investigate with particle physics, using particle accelerators. LHC is key.

3. .. and what it is made of.

4. nice … BUT

5. ? Mass up down e e charm strange top bottom quarks leptons

6. ? matter Big Bang: equal amounts of matter and antimatter created Now: we (matter) exist Why? anti

7. ? 96% of the universe?

8. How LHC helps LHC: creates fundamental particles in proton beam collisions Experiments: take 3D digital snapshots of particles produced in collisions Computers: reconstruct and identify particles detected in experiment Theory: infer which fundamental particles were originally created in collision Repeat ……….

9. Higgs; starting from this event… We look for this signature Selectivity: 1 in 10 13 Like looking for 1 person in 1000 world populations Or for a needle in 20 million haystacks! making sense of the data 40,000,000 proton-proton collisions/second ~100,000,000 electronic channels 0.0002 Higgs per second

10. HOW do we find anything? Distributed Computing Solution – Grid Concorde (15 Km) Balloon (30 Km) CD stack with 1 year LHC data! (~ 20 Km) Mt. Blanc (4.8 Km) …. a needle in 20 million haystacks! LHC produces enough data to fill 14 million cds / year (1,000,000 times world annual book production!!) Estimated we need 100,000 computers to analyse it all …..

11. grid! > 5000 computers at 17 sites in UK > 1 million computing jobs ran last year

12. Whats out there …. ? ……… wait and see what LHC tells us. Extra dimensions? Black holes? Higgs Particles? Strings?