Searching for the Higgs

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Searching for the Higgs spearheading grid
Tara Shears University of Liverpool
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Particle physics
WEAK
ELECTROMAGNETIC
STRONG
quarks
leptons
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What is mass?
property mediated by Higgs Particle
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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
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What is mass?
???
property mediated by Higgs Particle
nb we havent seen it yet ..
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Looking for Higgs - LHC
Worlds most powerful particle accelerator 2
beams of protons collide 40 million x a second 4
large experiments Due to start in 2007
27 km
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aside LHC vs. circle line
LHC Circle line Length
27km 22.5km Depth 100m
15m Diameter 3.8m 3.4m
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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
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Finding Higgs

• 800,000,000 proton-proton interactions per second
• 100,000,000 electronic channels
• 0.0002 Higgs per second

Starting from this event
We look for this signature
Selectivity 1 in 1013 Like looking for 1
person in a thousand world populations Or for a
needle in 20 million haystacks!
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HOW do we find the Higgs?
. 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 ..
Distributed Computing Solution Grid
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grid!
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summary
Search for origin of mass and Higgs major
unanswered question Hope for discovery at
LHC Immense technological and computing
challenge grid!