Large Hadron Collider:
Computing and its Hungarian Contribution
Dezs˝o Horváth
KFKI Research Institute for Particle and Nuclear Physics (RMKI), Budapest
and Institute of Nuclear Research (ATOMKI), Debrecen
Accelerators at CERN past and present
Where is the Higgs boson?
By-product
of spontaneous symmetry breaking
Most wanted particle of physics as
the only missing piece of the Standard Model.
Experimentally not
(yet?)
observed,
LEP:
M
(H) > 114.4 GeV
Theory: it
must
exist
as creates mass and removes divergences.
It was in 1972 ... that my life as a boson really began
Peter Higgs:
My Life as a Boson: The Story of „The Higgs”
,
Int. J. Mod. Phys. A
17
Suppl. (2002) 86-88.
LHC physics: Large Hadron Rap
Kate
McAlpine’s
song in
YouTube
explains
physics of
LHC
LHC: the dipole magnets
1232 superconducting dipoles (before installation)
(L
=
15
m,
M
=
35
t,
T
=
1
.
9
K,
B
=
8
.
3
T)
CMS at LHC
12500 ton digital camera:
100 M pixel, 40 M picture/s, 1000 GB/s data
Yield of colliding beams: luminosity
L
=
f n
N
1
N
2
A
f
: circulation frequency;
n
: number of bunches
N
1
,
N
2
protons/bunch;
A
: beam overlap
Rate of reaction with
σ
cross-section at
ε
efficiency
R
=
εσ
L
Integral luminosity: [fb
−
1
]
Accelerator collision
time
R
Ldt
energy
(fb
−
1
)
Tevatron
2 TeV
2001-2006
2.5
LHC
10 TeV
first few days
0.1
LHC
10 TeV
first few months
1
LHC: the Good, the Bad and the Ugly
Good
Enormous discovery potential:
Various reactions at very high
energies,
huge luminosity.
Bad
Terrible background,
interesting events happen
at probability
10
−
6
−
10
−
3
Ugly
Any interesting event is
accompanied by 10–20 p-p
collisions giving high combinatorial
backgrounds.
Worldwide LHC Computing Grid (WLCG)
At full luminosity the LHC experiments will produce
cca. 15 petabytes of data per year
Plus the same amount of simulations
Cannot be stored, handled and analyzed at CERN
Distributed by Worldwide LHC Computing Grid (WLCG)
Primary source: Tier-0, CERN
Storage, handling: Tier-1 centers
WLCG file transfer activity, 25.10.2008
Others:
Alice, BaBar, Biomed, DTeam, Dzero, ESR, Embrace, Gilda, Grid-IT,
GridPP, Hone, Inaf, LHCb, NGS, OPS, SEE, UKQCD, Zeus, aegis, ams, apesci,
argo, astro.vo.eu-egee.org, astron, astrop, auger, auvergrid, baikal, balticgrid, belle,
bg, bio, biowur, calice, camont.gridpp.ac.uk, cdf, cesga, compass, compchem,
cosmo, cppm, crypto.swing-grid.ch, cyclops, d4science.research-infrastructures.eu,
dca.euro-vo.org, dcms, dech, des, desy, diligent,
Other VO’s in WLCG (cont’d)
edteam, eearth, eela, egeode, egrid, eirevo.ie, enea, enmr.eu, euasia.euasiagrid.org,
euchina, euindia, eumed, fkppl.kisti.re.kr, fusion,fusion-rdig, gaussian, geant4, geclipse,
geclipsetutor, gene, ghep, glast.org, grid.uniovi.es, gridcc, gridmosi.ici.ro, herab,
her-mes,
hungrid
, icecube, ific, ilc, ildg, imath.cesga.es, infngrid, ingv, libi, lights.infn.it,
lo-far, magic, marine, minos, minos.vo.gridpp.ac.uk, na4.vo.eu-egee.org, na48, ncf, ndgf,
nordugrid.org, nw_ru, oper.vo.eu-eela.eu, osgedu, pamela, pheno, photon, planck,
pro-active, prod.vo.eu-eela.eu, pvier, rdteam, rfusion, rgstest, rhone-alpes-grid.fr, scier,
se-egrid, sixt, solovo, supernemo.vo.eu-egee.org, swetest, theophys, tps.infn.it, trgrida,
trgridb,
trgridc,
trgridd,
trgride,
trgridf,
trgridg,
twgrid,
uscms,
virgo,
vo.agata.org,
vo.apc.univ-paris7.fr, vo.cta.in2p3.fr, vo.dapnia.cea.fr, vo.deploymenttest.cea.fr, vo.e-ca.es,
vo.formation.idgrilles.fr, vo.gear.cern.ch, vo.grid.auth.gr, vo.grif.fr, vo.hess-experiment.eu,
vo.ipno.in2p3.fr,
vo.irfu.cea.fr,
vo.iscpif.fr,
vo.lal.in2p3.fr,
vo.lapp.in2p3.fr,
vo.llr.in2p3.fr,
vo.londongrid.ac.uk, vo.lpnhe.in2p3.fr, vo.lpsc.in2p3.fr, vo.northgrid.ac.uk, vo.pau.pic.es,
vo.paus.pic.es, vo.pic.es, vo.plgrid.pl, vo.renabi.fr, vo.rhone-alpes.idgrilles.fr, vo.sbg.in2p3.fr,
vo.scotgrid.ac.uk, vo.sixt.cern.ch, vo.southgrid.ac.uk, vo.testvo.cc.in2p3.fr, vo.ucad.sn, voce,
webcom, xfel.eu, xray.vo.eu-egee.org
WLCG: Hungarian Contribution
Four small Tier-2 sites in Hungary:
Eötvös Loránd University of Budapest
(ELTE): 40 CPU
Budapest University of Technology and Economy
(BMEGrid): 14 CPU
National Information Infrastructure Development
Institute (egee.grid.niif.hu): 12 CPU
KFKI Research Institute for Particle and Nuclear
Physics (BUDAPEST): 320 CPU
WLCG: Hungarian Contribution
RMKI started its grid site and joined LCG in 2003 as
BUDAPEST
Together with SZTAKI we develope and operate HunGrid for
Hungarian non-HEP academic users
Resource allocation of the capacity of BUDAPEST:
ALICE/CMS = 1/2, HunGrid by demand
CPU in kSI2000
ALICE: 115, CMS: 230, HunGrid: 20
Total CPU now 365 kSI2000,
by the end of 2008: 470 kSI2000
To be multiplied by 1.5 to get official LCG numbers.
Creating black holes?
Do we threaten the Earth, the Solar System, the Milky Way
or the whole Universe?
In the centers of galaxies black holes, BH:
M
BH
>
3
solar mass,
R
BH
few km
Some theoretical models predict production of short-lived,
microscopic black holes which evaporate immediately
Cosmic rays bombard everything with 1 000 000 000 times
the LHC energy since
10
10
years
Thus it is unprobable in LHC.
Preparing the LHC
Design starts in 1984
(5 years before the LEP start!)
Digging new caves from 1998
tunnel relaxes during
LEP use
⇒
compensate by correcting magnet
positions
LEP stop (stiff resistance): end of 2000.
Removal of LEP and its detectors: 2001
Testing (repairing!), lowering, installing 9300 magnets:
2002-2007.
Cooling to 1.9 K-re (cooler than the Cosmos): Jan-Aug
2008
Preparations for acceleration: the failure
Gradual increase of magnet currents to cca. 9000 A
sector by sector
Success in 7 sectors out of 8
19 Sep: At Sector 3-4 a faulty contact between two
magnets caused an arc which punched a cooling pipe.
Several tons of helium blew out displacing a few
magnets.
About 20 magnets have to be uninstalled, brought up
to the surface for reparation and replaced by spare
ones.
The LHC starts next spring
It does not work this year, but it may start 1 or 2
months earlier next year than originally planned
Of course, the experiments are not happy:
No p-p collisions at 900 GeV for testing and
calibrating detector elements.
The LHC tunnel will be closed earlier next year,
some additionally ordered detector components
may not arrive by then for installation.
Such failures may always happen, they do not threaten
the whole project...
21 Oct: Big LHC celebration with ministers, presidents
from all member states
Acknowledgements
National Science Foundation and National Bureau
Science and Development
OTKA NK67974, K72172, H07C-74153 and TéT
JAP-21/2006
EU FP6 MC-ToK 509252 and FP7 III 031688
Hungarian and Austrian Academies of Sciences
