1. Searching for the Higgs – spearheading grid Tara Shears University of Liverpool

2. Particle physics up down e e charm strange   top bottom   quarks leptons WEAKELECTROMAGNETICSTRONG

3. What is mass? …property mediated by “Higgs Particle”

4. Analogy Interaction with Higgs field ( mass) ~ movement of body through medium Light particles do not interact much (move fast) More interaction – slower movement – more mass conferred Heaviest particles …. most interaction

5. What is mass? …property mediated by “Higgs Particle” nb …… we haven’t seen it yet ….. ??????

6. Looking for Higgs - LHC World’s most powerful particle accelerator 2 beams of protons collide 40 million x a second 4 large experiments Due to start in 2007 27 km ? ? ?

7. aside: LHC vs. circle line LHC Circle line Length 27km 22.5km Depth 100m 15m Diameter 3.8m 3.4m

8. Looking for Higgs - experiment eg. …the ATLAS experiment: 5 storey building 7,000 tonnes 42m long 22m wide 22m high 2,000 Physicists 150 Institutes 34 Countries

9. Starting from this event… We look for this “signature” Selectivity: 1 in 10 13 Like looking for 1 person in a thousand world populations Or for a needle in 20 million haystacks! Finding Higgs 800,000,000 proton- proton interactions per second ~100,000,000 electronic channels 0.0002 Higgs per second

10. HOW do we find the Higgs? 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!

12. summary Search for origin of mass and Higgs major unanswered question Hope for discovery at LHC Immense technological and computing challenge: grid!