why lhc? tara shears, university of liverpool. to understand the universe … fundamental particles...
TRANSCRIPT
Why LHC?
Tara Shears, University of Liverpool
To understand the universe …
Fundamental particles → atoms → stars and galaxies
NOWInvestigate with astrophysics,
using telescopes
BIG BANGInvestigate with
particle physics, usingparticle accelerators.
LHC is key.
.. and what it is made of.
nice …
BUT
? Massup
down
e
e
charm
strange
top
bottom
qu
ark
sle
pto
ns
? matterBig Bang: equal amounts of matter and antimatter created
Now: we (matter) exist
Why?
anti
? 96% of the universe?
How LHC helpsLHC: creates fundamental particles in
proton beam collisions Experiments: take 3D digital snapshots
of particles produced in collisionsComputers: reconstruct and identify
particles detected in experimentTheory: infer which fundamental
particles were originally created in collision
Repeat ……….
Higgs; starting from this event…
We look for this “signature”Selectivity: 1 in 1013
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
HOW do we find anything?
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!
> 5000 computers at 17 sites in UK
> 1 million computing jobs ran last year
What’s out there ….
?……… wait and see what LHC tells us.
Extra dimensions?
Black holes?Higgs
Particles?
Strings?