Compact Muon Solenoid Experiment - CERNcds.cern.ch/record/2205195/files/CMS Brochure 2003.pdf · temperature is too high for quarks to remain clumped to form neutrons or protons and

http://cmsinfo.cern.ch/

CMS Collaboration

Compact Muon Solenoid Experiment

CMS Collaboration. June 2003http://cmsinfo.cern.ch/Brochures/IntroToCMS.pdf

e-mail : [email protected]

Table of contents

The story of the Universe

Particles and forces

CERN & LHC

The Compact Muon Solenoid

01.05.03v2 The story of the Universe

The story of the Universe

5

Quantum gravity era

Grand unification era

Electroweak era

Protons and neutrons form

Nuclei are formed

Atoms and light era

Galaxy formation

Today

The size of things

Particle Physics

From the Big Bang to today's Universe


Quantum gravity era

6

10-43 s

?

t < 10-43 s : The Big BangThe universe is considered to have expanded from a single point with an infinitely high energy density (infinite temperature). Is there a meaning to the question what existed before the big bang?

t ≈ 10-43 s, 1032 K (1019 GeV, 10-34 m) : Gravity “freezes” out All particle types (quarks, leptons, gauge bosons, and undiscovered particles e.g.Higgs, sparticles, gravitons) and their anti-particles are in a thermal equilibrium (being created and annihilated at equal rate). These coexist with photons (radiation).Through a phase transition gravity "froze" out and became distinct in its action from the weak, electromagnetic and strong forces. The other three forces could not be distinguished from one another in their action on quarks and leptons. This is the first instance of the breaking of symmetry amongst the forces.

Gravity separates as a force, the other forces remain as one (Grand Unification)


Grand unification era

7

10-35 s

t ≈ 10-35 s, 1027 K (1016 GeV, 10-32 m) : Inflation The rate of expansion increases exponentially for a short period. The universe doubled in size every 10-34 s. Inflation stopped at around 10-32 s. The universe increased in size by a factor of 1050. This is equivalent to an object the size of a proton swelling to 1019 light years across. The whole universe is estimated to have had a size of ~1023 m at the end of the period of inflation. However the presently visible universe was only 3 m in size after inflation. This solves the problems of ‘horizon’ (how is it possible for two opposing parts of the present universe to be at the same temperature when they cannot have interacted with each other before recombination) and ‘flatness’ (density of matter is close to the critical density).

t ≈ 10-32 s : Strong forces freezes outThrough another phase transition the strong force "freezes" out and a slight excess of matter over anti-matter develops. This excess, at a level of 1 part in a billion, is sufficient to give the presently observed predominance of matter over anti-matter. The temperature is too high for quarks to remain clumped to form neutrons or protons and so exist in the form of a quark gluon plasma. The LHC can study this by colliding together high energy nuclei.

Inflation ceases, expansion continues Grand Unification breaks. Strong and electroweak

forces become distinguishable


Electroweak era

8

10-10 s

t ≈ 10-10 s, 1015 K (100 GeV, 10-18 m) : Electromagnetic and Weak Forces separate The energy density corresponds to that at LEP. As the temperature fell the weak force "freezes" out and all four forces become distinct in their actions. The antiquarks annihilate with the quarks leaving a residual excess of matter. W and Z bosons decay. In general unstable massive particles disappear when the temperture falls to a value at which photons from the black-body radiation do not have sufficient energy to create a particle-antiparticle pair.

Electroweak force splits


Protons and neutrons form

9

10-4 s

t ≈ 10-4 s, 1013 K (1 GeV, 10-16 m) : Protons and Neutrons form The universe has grown to the size of our solar system. As the temperature drops quark-antiquark annihilation stops and the remaining quarks combine to make protons and neutrons.

t = 1 s, 1010 K (1 MeV, 10-15 m) : Neutrinos decouple The neutrinos become inactive (essentially do not participate further in interactions). The electrons and positrons annihilate and are not recreated. An excess of electrons is left. The neutron-proton ratio shifts from 50:50 to 25:75.

Quarks combine to make protons and neutrons


Nuclei are formed

10

100 s

t = 3 minutes, 109 K (0.1 MeV, 10-12 m) : Nuclei are formed The temperature is low enough to allow nuclei to be formed. Conditions are similar to those that exist in stars today or in thermonuclear bombs. Heavier nuclei such as deuterium, helium and lithium soak up the neutrons that are present. Any remaining neutrons decay with a time constant of ~ 1000 seconds. The neutron-proton ratio is now 13:87. The bulk constitution of the universe is now in place consisting essentially of protons (75%) and helium nuclei. The temperature is still too high to form any atoms and electrons form a gas of free particles.

Protons and neutrons combine to form helium nuclei

01.05.03v2 The story of the Universe 11

Atoms and light era300000 years

t = 300 000 years, 6000 K (0.5 eV, 10-10 m) : Atoms are created Electrons begin to stick to nuclei. Atoms of hydrogen, helium and lithium are created. Radiation is no longer energetic enough to break atoms. The universe becomes transparent. Matter density dominates. Astronomy can study the evolution of the Universe back to this time.

The Universe becomes transparent and fills with light


Galaxy formation1000 million years

t = 109 years, 18 K : Galaxy Formation Local mass density fluctuations act as seeds for stellar and galaxy formation. The exact mechanism is still not understood. Nucleosynthesis, synthesis of heavier nuclei such as carbon up to iron, starts occurring in the thermonuclear reactors that are stars. Even heavier elements are synthesized and dispersed in the brief moment during which stellar collapse and supernovae explosions occur.

Galaxies begin to form


Today15000 million years

t = 15 x 109 years, 3 K : Humans The present day. Chemical processes have linked atoms to form molecules. From the dust of stars and through coded messages (DNA) humans emerge to observe the universe around them.

Man begins to wonder where it all came from

01.05.03v2 Particles and forces 14

10-34

10-30

10-26

10-22

10-18

10-14

10-10

10-6

1m

106

1010

1014

1018

1022

1026

Earth radiusEarth to Sun

Galaxies

ObservablesInstruments

ProtonNuclei

Microscope

Telescope

RadioTelescope

VirusCell

Atom

SUSY particle?Higgs?Z/W (range of

weak force) (range of nuclear force)

(Particle beams)

ElectronMicroscope

Radius of observable Universe

Big Bang

Universe

LHCLEP

taAccelerators

The size of things


Particle Physics

15

Aim to answer the two following questions

- What are the elementary constituents of matter?

- What are the fundamental forces that control their behavior at the most basic level?

01.05.03v2 Particles and forces

Particles and forces

Particles

Forces

Interactions: coupling of forces to matter

Short history and new frontiers

Unification of forces

Summary

17


Tau

Muon

Electron

TauNeutrino

MuonNeutrino

ElectronNeutrino

Bottom

Strange

Down

Top

Charm

Up

Particles

Leptons

-1

-1

-1

0

0

0

2/3

2/3

2/3

-1/3

-1/3

-1/3

Electric Charge

Electric Charge

Electric Charge

Electric Charge

Quarks

each quark: R, B, G 3 colorsThe particle drawings are simple artistic representations


Forces

Gluons (8)

Quarks

MesonsBaryons Nuclei

Graviton ? Bosons (W,Z)

AtomsLightChemistryElectronics

Solar systemGalaxiesBlack holes

Neutron decayBeta radioactivityNeutrino interactionsBurning of the sun

Strong

Photon

Electromagnetic

Gravitational Weak

The particle drawings are simple artistic representations

01.05.03v2 Particles and forces

Interactions: coupling of forces to matter

20

u

Wd

e-

νe

Zo

e- e-

e+ e+

Strong

q

q

q'

q'

q q

q' q'

e- e-

g

gg

W

u d

e- νe

e- Zo

e+

e-

e+

Charged Neutral

g

g

g

Weak

Electroweak

qγ

q

e+

e-

γ

e+ e+

Electromagnetic

Range ∞, relative strength ≤ 10-2 Range ~10-18 m, relative strength 10-14

Range ~ 10-15 m, relative strength = 1

g

g g

g g


ud

cs

tb

eνe

µνµ ντ

τ

6 Quarks

6 Leptons

3 "Colors" each quark R G B

u e+Z

10-10 m ≤ 10 eV Quantum MechanicsAtomic Physics

>300000 Y

10-15 m MeV - GeV Nuclei, HadronsSymmetriesField theories

Quantum Electro Dynamics

10-16 m >> GeV QuarksGauge theories

≈ 10-6 sec

10-18 m ≈ 100 GeV ElectroWeak Unification, QCD

≈ 10-10 sec

1900....

1940-50

1950-65

1965-75

LEP 1990

3 families

10-19 m ≈ 103 GeVOrigin of massesThe next step...

≈ 10-12 sec

LHC 2005

SPS, pp 1970-83

λ = h / p T ≈ t -1/2

≈ 3 min

Higgs ? Supersymmetry ?

10-32 m ≈ 1016 GeV ≈ 10-32 secProton Decay ? GRAND Unified Theories ?

Underground Labs

10-35 m ≈ 1019 GeV(Planck scale)

≈ 10-43 secQuantum Gravity? Superstrings ?

??The Origin of the Universe

Top quark

Tevatron 1994

e-u

Short history and new frontiers

γe+

e-

γ


Terrestrial mechanics

Universal GravitationInertial vs. Gravitational mass(I. Newton, 1687 )

Electricity

Magnetism

ElectromagnetismElectromagnetic waves (photon)(J.C. Maxwell, 1860 )

Electromagnetism

Weak force

Electroweak Intermediate bosons W, Z(1970-83 )

Probing shorter distances reveals

deeper regularities

UNIFIED DESCRIPTIONS

?

Unification of forces

Celestial mechanics

γγ

n

p

e-

νe

+ −−−−

N S


10-43 sec 10-32 sec 10-10 sec 10-4 sec 100 sec 300000 years

10-35 m 10-32 m 10-18 m 10-16 m 10-15 m 10-10 m1019 GeV 1016 GeV 102 GeV 1 GeV 1 Mev 10 eV

Theories:

STRINGS? RELATIVISTIC/QUANTUM CLASSICAL

Summary

Quantum Gravity

Super Unification

Grand

Unification

Electroweak

Model

QED

Weak Force

Nuclear Force

Electricity

Magnetism

Maxwell

Short range

Fermi

QCD

Long range

Short range

Terrestrial

Gravity

Celestial Gravity

Einstein, Newton

Galilei

Kepler

Long range

?

Universal Gravitation

Electro

Magnetism

Weak TheoryStandard

model

SU

SY

?

01.05.03v2 CERN & LHC 25

CERN & LHC

CERN: The Laboratory

The Large Hadron Collider (LHC)

Collisions at LHC

Detectors at LHC

01.05.03v2 CERN & LHC

• International organization established in 1954

• 19 member states + observers • Today about half of the world's high-energy

physics experiments are performed at CERN

• Dedicated to basic research on

elementary constituents of matter and their

fundamental interactions

26

CERN: The Laboratory

If you want to know more about CERN, find out through the Laboratory's invention the World-Wide Web: http://www.cern.ch/

01.05.03v2 CERN & LHC 27

Superconducting magnets

SPS

PS

CMSCompact Muon Solenoid

The Large Hadron Collider (LHC)

LHC-B

ALICE

From LEP to LHC

ATLAS

Beams Energy Luminosity

e+ e- 200 GeV 1032 cm-2s-1

p p 14 TeV 1034

Pb Pb 1312 TeV 1027

LEP

LHC

01.05.03v2 CERN & LHC 28

Selection of 1 in 10,000,000,000,000

Collisions at LHC

01.05.03v2 CERN & LHC

Detectors at LHC

29

Each layer identifies and enables the measurement of the momentum or energy of

the particles produced in a collision

Central detector• Tracking, p

T, MIP

• Em. shower position• Topology• Vertex

Electromagnetic and Hadron calorimeters• Particle identification (e, γ Jets, Missing E

T)

• Energy measurement

µµnn

pp

γγγγγγγγ

Heavy materials

νννννννν

Heavy materials(Iron or Copper + Active material)

ee

Materials with high number of protons + Active material

Light materials

Muon detector• µ identification

Hermetic calorimetry• Missing Et measurements

01.05.03v2 The Compact Muon Solenoid 31

The Compact Muon Solenoid

CMS experiment

CMS layout and detectors

CMS trigger and data acquisition

CMS physics : Higgs

CMS physics : CP violation

CMS physics : Supersymmetry


CMS experiment

CMS detector longitudinal view

CMS is a general purpose proton-proton detector designed to run at

the highest luminosity at the LHC. It is also well adapted for studies at

the initially lower luminosities. The main design goals of CMS are:

1) a highly performant muon system

2) the best possible electromagnetic calorimeter

3) a high quality central tracking

4) a hermetic hadron calorimeter

01.05.03v2 The Compact Muon Solenoid

MUON BARREL

CALORIMETERS

Silicon MicrostripsPixels

HCAL Plastic scintillator brass

sandwich

ECAL Scintillating PbWO4

Crystals

Cathode Strip Chambers (CSC)Resistive Plate Chambers (RPC)

Drift Tube Chambers (DT)

Resistive Plate Chambers (RPC)

strips

wire

sµ

43

21

Total weight : 12,500 tOverall diameter : 15 mOverall length : 21.6 mMagnetic field : 4 Tesla

SUPERCONDUCTING COIL

IRON YOKE

TRACKER

MUON ENDCAPS

CMS layout and detectors

33


CMS trigger and data acquisition

34

16 Million channels

40 MHz COLLISION RATE

100 kHz LEVEL-1 TRIGGER

1 Megabyte EVENT DATA

200 Gigabyte BUFFERS 500 Readout memories

3 Gigacell buffers

500 Gigabit/s

5 TeraFLOP

Gigabit/s SERVICE LAN

Petabyte ARCHIVE

Energy Tracks

100 HzFILTERED EVENT

EVENT BUILDER. A large switching network (512+512 ports) with a total throughput of approximately 500 Gbit/s forms the interconnection between the sources (Readout Dual Port Memory) and the destinations (switch to Farm Interface). The Event Manager collects the status and request of event filters and distributes event building commands (read/clear) to RDPMs

EVENT FILTER. It consists of a set of high performance commercial processors organized into many farms convenient for on-line and off-line applications. The farm architecture is such that a single CPU processes one event

SWITCH NETWORK

1 Terabit/s (50000 DATA CHANNELS)

COMMUNICATION

PROCESSING

Tera : 1012; Peta 1015; LAN : Local Area Network


CMS physics : Higgs

Higgs to 2 photons (MH < 140 GeV)

Higgs to 4 leptons (140 < MH< 700 GeV)

Higgs to 2 leptons+2 jets (MH > 500 GeV)

35

The Standard Model (SM) of Particle Physics has unified the electromagnetic interaction (carrier: γ) and the weak interaction (carriers: W+, W-, Z0). Yet these four bosons are very different: the γ is massless whereas the W± and Z0 are quite massive (80 and 90 GeV respectively). In the framework of the SM particles acquire mass through their interaction with the Higgs field. This implies the existence of a new particle: the Higgs boson H0. The theory only provides a general upper mass limit of about 1 TeV, but it does predict its production rate and decay modes for each possible mass. CMS has been optimized to discover the Higgs up to a mass of 1 TeV. Examples of decay modes are:


36

p p

γγγγ

γγγγ

H

MHiggs

= 100 GeV

H0 → γγ is the most promising channel if M

H is in the range 80 – 140 GeV.

The high performance PbWO4 crystal

electromagnetic calorimeter in CMS has been optimized for this search. The γγ mass resolution at Mγγ ~ 100 GeV is better than 1%, resulting in a S/B of ≈1/20

4000

5000

6000

7000

8000

110 120 130 140

Eve

nts/

500

MeV

for

100

fb–1

Higgs signal

H → γγ

Mγγ (GeV)

Higgs to 2 photons (MH < 140 GeV)


Higgs to 4 leptons (140 < MH< 700 GeV)

37

p pH

µ+

µ-

µ+

µ-

Z

Z

In the MH range 130 - 700 GeV the most

promising channel is H0 → ZZ*→ 2,+ 2,– or H0 → ZZ → 2,+ 2,– . The detection relies on the excellent performance of the muon chambers, the tracker and the electromagnetic calorimeter. For M

H ≤ 170 GeV a mass resolution of

~1 GeV should be achieved with the combination of the 4 Tesla magnetic field and the high resolution of the crystal calorimeter

6080

2040

120 140 160 180

M4 ± (GeV)

Eve

nts

/ 2 G

eV

H→ZZ*→ 4 ±

MHiggs

= 150 GeV


yyyyyyyyyyyyyyyyyyyyyyyyyyy

yyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyy

yyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyy

yyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyy

38

Higgs to 2 leptons+2 jets (MH > 500 GeV)

5

4

3

2

1

200 600 1000 1400 1800

MIIjj (GeV)

Eve

nts

/ 20

0GeV

for

105 p

b-1

SignalBkgd

H→ ZZ → jj

p pH

jet jet

e+

e-

Z

Z

For the highest MH, in the range

0.5 - 1 TeV, the promising channels for one year at high luminosity are H0 → ZZ → ,+ ,– νν, H0 → ZZ → ,+ ,– jj and H0 → W+ W- → ,± ν jj . Detection relies on leptons, jets and missing transverse energy (E

tmiss),

for which the hadronic calorimeter (HCAL) performance is very important

MHiggs

= 800 GeV


The strength of the four known forces (electromagnetic, weak, strong and gravity) does not depend on whether the particles that experience them are made of matter or antimatter. Yet, the universe we live in is completely dominated by matter. How did the universe evolve into this very asymmetric state when the underlying forces do not know the difference between matter and antimatter? A clue into this question may be provided by the phenomenon of Charge-Parity (CP) violation, discovered over three decades ago in decays of neutral kaons (K0); these are mesons containing a strange (s) quark.

CP violation implies that there is a small difference in the decay rates of K0 and K0 mesons. One possible explanation is that there exists yet another, undiscovered, force in nature, that is not matter-antimatter symmetric. Another, more popular explanation is that the weak interaction, through which kaons decay, can actually distinguish between matter and antimatter particles. If this is true, one should be able to observe a large asymmetry in the decay rates of matter vs antimatter mesons that are made of quarks heavier than the s. The best candidate is the b quark which forms B mesons.

CMS physics : CP violation

B physics


0

4.8 5.0 5.2 5.4 5.6

Eve

nts

/ 10

MeV

1500

2000

1000

500

(GeV) π–π+Mµ+µ–

pp→bb → µtag + B o + Xd

s J/ψ Ko

π–π+µ+µ–

40

B physics

The decay B0 or B0 → J/ψ K0S

presents a very clean experimental signature. The particle content (B0

or B0 meson) that gave the decay can be determined from a muon from the second b-flavored hadron in the event. An asymmetry in the two rates (B0 vs B0) would signal CP violation. This would be the first time that CP violation is observed outside the neutral kaon system

—

+

p p

µ—

B0Z

b

µ— µ+

jet

b


CMS physics : Supersymmetry

SUSY Higgs bosons

SUSY Higgs: discovery ranges

Sparticles

Sparticles: discovery ranges

41

Supersymmetry (SUSY) postulates a relationship between matter particles (spin-1/2 or "fermions") and force carriers (integer spin or "bosons") which is not present in the Standard Model (SM). In SUSY, each fermion has a "superpartner" of spin-0 while each boson has a spin-1/2 superpartner. The Higgs sector is also extended to at least five Higgs bosons in the Minimal Supersymmetric Standard Model (MSSM). To this day, no superpartners have been observed: SUSY must be a broken symmetry, i.e. the superpartners (sparticles) must have masses different than those of their partner particles. Despite the doubling of the spectrum of particles, SUSY has many merits: it is elegant; assuming the existence of superpartners with TeV-scale masses, the Strong, Weak and Electromagnetic force strengths become equal at the same energy of ~ 1016 GeV (the "GUT scale"); it also provides a natural explanation of why the Higgs mass can be low (< 1 TeV). In SUSY theories, there is even room for explaining the dark matter in the Universe as "neutralinos" (the lightest SUSY particles LSP). If SUSY is a true symmetry of Nature and it is realized at the TeV scale, it will almost certainly be discovered in CMS


SUSY Higgs bosons

42

In the MSSM there are 5 Higgs bosons: h0, H0, A0 and H± decaying through a variety of decay modes to γ, e±, µ±, τ± and jets in final states. Below left: an example of a SUSY Higgs decay to τ τ in CMS. On the right is the reconstructed ττ mass spectrum

H → ττ → e + τjet

("3-prong")0 100 200 300 400 500

m ττ (GeV)

mA = 300 GeV, tan β = 40with b - tagging

Total background

40

60

80

100

120

140

20

Eve

nts

for

3x10

4 pb

- 1 /

20 G

eV

A0, H0, h0 → τ+τ− → e/µ + τjet + Etmiss

in bbHSUSY final states

3 * 104 pb-1

Signal

τjet

e

p pH

e+

τ−

τ+

νe

ντ

ντ

π−

π+π−


SUSY Higgs: discovery ranges

43

Higgs bosons in MSSM

→A,H,h µµ

LEP IIs= 192 GeV

mtop = 175 GeV, mSUSY = 1 TeV5 σ significance contours

50

0 100 200 300 400 500

20

10

5

2

10 100 200

tan

β

3.104 pb-1→→A,H,h ττ ±+ h± + X

→H± τν, 104 pb-1

mA (GeV)

105 pb-1

→h γγ inclusive

A0 = 0, tanβ = 30, µ > 0

TH

EX

h(116)

h(120)

100 fb-1

800

700

600

500

400

300

200

100

0 200 400 600 800 1000 1200 1400m0 (GeV)

m1/

2 (

GeV

)

10 fb-1

Mbb

S / B > 5

The search for the various MSSM Higgs bosons in different decay modes allows the exploration of most of the parameter region (tanβ,m

A)

Example of the domain of parameter space of mSUGRA-MSSM where the h0 can be discoveredvia its decay in bb


Eve

nts

/ 2G

eV

SUSY + SM

SM

250

200

150

100

50

0 50 100 150 200 250

Emiss > 100 GeVt

p 1,2 > 15 GeVt

Lint = 103 pb-1

M ( + -), GeV

Inclusive e+e–+ Emiss final states t

m0 = 200 GeV, m1/2 = 160 GeV,tanβ = 2, A0 = 0, µ<0

mSUGRA parameters

Sparticles

44

Production of sparticles may reveal itself though some spectacular kinematical spectra, with a pronounced "edge" in the ,+, – mass spectrum reflecting χ

20 → ,+, – χ

1o

production and decay. An example of such a spectrum in inclusive ,+, – + E

tmiss and of a 3 ,±

production event are shown below

SUSY event with 3 leptons + 2 Jets signature

p p

e- νe

µ+

µ−

q

q

q

qχ

1

-

g~

~

χ2

0~

q~

χ1

0~

χ1

0~

Jet1Jet2

µ+µ

-

χ01

~

e-

χ01

~

-


Domains of mSUGRA parameter space (m0,m1/2) where various sparticles can be identified

1000

800

600

400

200

0 400 800 1200 1600 2000m0 GeV

m1/

2, G

eV

q (2000)

~

g (2000)~

tan β = 2, A0 = 0, µ < 0

(40

0)

Ω h2= 0.4

Ω h2= 0.15

~

L

105pb-1

g,q → n + X~~

45

Sparticles cannot escape discovery at the LHC

Gluinos and squarks can be searched for in various channels with leptons + E

tmiss

+ jets and discovered for masses up to ~ 2.2 TeV. Sleptons can be discovered for masses up to ~ 350 GeV. The region of parameter space 0.15 < Ω h2 < 0.4 — where LSP would be the Cold Dark Matter particle — is contained well within the explorable region

Sparticles: discovery ranges


In total CMS will have 15,000,000 individual detector channels, all of which will be controlled by powerful computers. These will synchronize the detector with the LHC accelerator, making sure that CMS is ready to record any interesting collisions.

CMS

At the LHC, bunches of protons will pass through each other 40 million times a second, and with each bunch crossing, 20 protons-proton collisions will occur on average, making 800 million collisions per second. Not all of these will produce interesting results. Most of the time, protons will just graze past each other. Head-on collisions will be quite rare, and the processes which produce new particles rarer still. The Higgs boson, for example, is expected to appear in just one of every 1013 (10,000,000,000,000) collisions. That means that even with 800 million collisions a second, a Higgs boson would only appear about once every day. Needles in haystacks seem like child’s play in comparison.

CER

N L

HC

CMS collaboration(152 Institutions with about 1900 scientists)

23.0

7.9

8

Slovak Republic

CERN

France

Italy

UK

Switzerland

USA

Austria

Finland

Greece

Hungary

Poland

Portugal

SpainPakistan

Georgia

Armenia

Ukraine

Uzbekistan

Cyprus

Croatia

China, PR

Turkey

Belarus

Estonia

India

Germany

Korea

Russia

BulgariaBelgium

China (Taiwan)

Iran

Serbia

New-Zealand

Brazil

Ireland

•Yerevan Physics Inst., Yerevan

•HEPHY, Wien

• Institute of Nuclear Problems, Minsk

•National Centre of Part. and HEP, Minsk

•Res. Inst. of Applied Physical Probl., Minsk

•Byelorussian State Univ., Minsk

•Univ. Instelling Antwerpen, Wilrijk

•Univ. Libre de Bruxelles, Brussels

•Vrije Universiteit Brussel, Brussels

•Univ. Catholique de Louvain, Louvain-la-Neuve

•Univ. de Mons-Hainaut, Mons

• Inst. for Nucl. Res. and Nucl. Energy, Sofia

•Univ. of Sofia, Sofia

• Inst. of High Energy Physics, Beijing

•Peking Univ., Beijing

•Univ. for Science & Tech. of China, Hefei, Anhui

•Tech. Univ. of Split, Split

•Univ. of Split, Split

•Univ. of Cyprus, Nicosia

• Inst. of Chemical Phys. and Biophys., Tallinn

•Helsinki Institute of Physics , Helsinki

•Dpt. of Phys., Univ. of Helsinki, Helsinki

•Univ. of Oulu, Oulu

•Tampere Univ. of Tech., Tampere

ARMENIA

AUSTRIA

BELARUS

BELGIUM

BULGARIA

CHINA, PR

CROATIA

CYPRUS

ESTONIA

FINLAND

FRANCE

•LAPP, IN2P3-CNRS, Annecy-le-Vieux

• IPN, IN2P3-CNRS, Univ. Lyon I, Villeurbanne

•LPNHE, Ecole Polytech., IN2P3-CNRS, Palaiseau

•DSM/DAPNIA, CEA/Saclay, Gif-sur-Yvette

• IRES, IN2P3-CNRS - ULP, UHA, LEPSI, Strasbourg

• High Energy Phys. Inst., Tbilisi State Univ., Tbilisi

• Inst. of Physics Academy of Science, Tbilisi

• RWTH, I. Physik. Inst., Aachen

• RWTH, III. Physik. Inst. A, Aachen

• RWTH, III. Physik. Inst. B, Aachen

• Inst. für Exp. Kernphysik, Karlsruhe

GEORGIA

GERMANY

•

• Quaid-I-Azam Ghulam Ishaq Khan Institute, Swabi

Univ., Islamabad

PAKISTAN

• Inst. of Exp. Phys., Warsaw

• Soltan Inst. for Nucl. Studies, Warsaw

• LIP, Lisboa

• JINR, Dubna

• Inst. for Nucl. Res., Moscow

• Inst. for Theoretical and Exp. Phys., Moscow

• P.N. Lebedev Phys. Inst., Moscow

• Moscow State Univ., Moscow

• Inst. for High Energy Phys., Protvino

• Petersburg Nucl. Phys. Inst., Gatchina (St Petersburg)

• Slovak University of Technology, Bratislava

• CIEMAT, Madrid

• Univ. Autónoma de Madrid, Madrid

• Bogazici University, Dep. of Physics, Instambul (Bebek)

• Univ. de Oviedo, Oviedo

• IFCA, CSIC-Univ. de Cantabria, Santander

• Univ. Basel, Basel

• CERN, Geneva

• Paul Scherrer Inst., Villigen

• Inst. für Teilchenphysik, ETH, Zurich

• Univ. Zürich, Zurich

• Cukurova Univ., Adana

• Middle East Technical Univ., Ankara

• Inst. of Single Crystals of Nat. Acad. of Science, Kharkov

• Kharkov Inst. of Phys. and Tech., Kharkov

• Kharkov State Univ., Kharkov

POLAND

PORTUGAL

RUSSIA

SLOVAK REPUBLIC

SPAIN

SWITZERLAND

TURKEY

• National Central University, Chung-Li, Taipei

• National Taiwan University, Taipei

TAIPEI

UKRAINE

UNITED KINGDOM

• Univ. of Bristol, Bristol

• Brunel Univ., Uxbridge

• Imperial College, Univ. of London, London

• RAL, Didcot

• Univ. of Alabama, Tuscaloosa

• Iowa State Univ., Ames

• Boston Univ., Boston

• California Inst. of Tech., Pasadena

• Carnegie Mellon Univ., Pittsburgh

• Univ. of Illinois at Chicago, Chicago

• Fairfield Univ., Fairfield

• Fermi National Accelerator Lab., Batavia

• Florida State Univ. - HEPG, Tallahassee

• Florida State Univ. - SCRI, Tallahassee

• Univ. of Florida, Gainesville

• The Univ. of Iowa, Iowa City

• Johns Hopkins Univ., Baltimore

• LLNL, Livermore

• Los Alamos Nat. Lab., Los Alamos

• Univ. of Maryland, College Park

• Univ. of Minnesota, Minneapolis

• Univ. of Mississippi, Oxford

• Massachusetts Inst. of Tech., Cambridge

• Univ. of Nebraska-Lincoln, Lincoln

• Northeastern Univ., Boston

• Northwestern Univ., Evanston

• Univ. of Notre Dame, Notre Dame

• The Ohio State Univ., Columbus

• Princeton Univ., Princeton

• Purdue Univ. , West Lafayette

• Rice Univ., Houston

• Univ. of California, Riverside

• Univ. of Rochester, Rochester

• Rutgers, the State Univ. of New Jersey, Piscataway

• Texas Tech Univ., Lubbock

• Univ. of Texas at Dallas, Richardson

• Univ. of California at Davis, Davis

• UCLA, Los Angeles

• Univ. of California San Diego, La Jolla

• Virginia Polytech. Inst. and State Univ., Blacksburg

• Univ. of Wisconsin, Madison

USA

UZBEKISTAN

• Inst. of Nucl. Phys. of the Uzbekistan Acad. of Sciences, Tashkent

• Univ. of Athens, Athens

• Inst. of Nucl. Phys. "Demokritos", Attiki

• Univ. of Ioánnina, Ioánnina

• KFKI Res. Inst. for Part. & Nucl. Phys., Budapest

• Kossuth Lajos Univ., Debrecen

• Institute of Nuclear Research ATOMKI, Debrecen

• Panjab Univ., Chandigarh

• Bhabha Atomic Res. Centre, Mumbai

• Univ. of Delhi South Campus, New Delhi

• TIFR - EHEP, Mumbai

• TIFR - HECR, Mumbai

• Univ. di Bari e Sez. dell' INFN, Bari

• Univ. di Bologna e Sez. dell' INFN, Bologna

• Univ. di Catania e Sez. dell' INFN, Catania

• Univ. di Firenze e Sez. dell' INFN, Firenze

• Genova e Sez. dell' INFN, Genova

• Univ. di Padova e Sez. dell' INFN, Padova

• Univ. di Pavia e Sez. dell' INFN, Pavia

• Univ. di Perugia e Sez. dell' INFN, Perugia

• Univ. di Pisa e Sez. dell' INFN, Pisa

• Univ. di Roma I e Sez. dell' INFN, Roma

• Torino e Sez. dell'INFN, Torino

GREECE

HUNGARY

INDIA

ITALY

KOREA• Cheju National University, Cheju

• Chonnam National University, Kwangju

• Choongbuk National University, Chongju

• Dongshin University, Naju

• Kangnung National University, Kangnung

• Kangwon National University, Chunchon

• Kon-Kuk University, Seoul

• Korea University, Seoul

• Kyungpook National University, Taegu

• Seoul National University, Seoul

• Seonam University, Namwon

• Seoul National Univ. of Education, Seoul

• Wonkwang University, Iri

Univ. di

Univ. di

• Gyeongsang National University, Jinju

• Institute for Studies in Theoretical Phy. and Math., Teheran

IRAN

Documents

Compact Muon Solenoid Experiment - CERNcds.cern.ch/record/2205195/files/CMS Brochure 2003.pdf · temperature is too high for quarks to remain clumped to form neutrons or protons and