searching for the higgs – spearheading grid tara shears university of liverpool
Post on 23-Jan-2016
217 views
TRANSCRIPT
Searching for the Higgs – spearheading grid
Tara Shears
University of Liverpool
Particle physics
up
down
e
e
charm
strange
top
bottom
qu
ark
sle
pto
ns
WEAKELECTROMAGNETICSTRONG
What is mass?
…property mediated by “Higgs Particle”
AnalogyInteraction 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
What is mass?
…property mediated by “Higgs Particle”
nb …… we haven’t seen it yet …..
???
Looking for Higgs - LHCWorld’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
?
?
?
aside: LHC vs. circle line
LHC Circle line
Length 27km 22.5km
Depth 100m 15m
Diameter 3.8m 3.4m
Looking for Higgs - experiment
eg. …the ATLAS experiment:
5 storey building 7,000 tonnes 42m long 22m wide 22m high2,000 Physicists 150 Institutes 34 Countries
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!
Finding Higgs• 800,000,000 proton-
proton interactions per second
• ~100,000,000 electronic channels
• 0.0002 Higgs per second
HOW do we find the Higgs?
Distributed Computing Solution – Grid
Concorde(15 Km)
Balloon(30 Km)
CD stack with1 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 …..
grid!
summarySearch for origin of mass and Higgs major unanswered question
Hope for discovery at LHC
Immense technological and computing challenge: grid!