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Some predictions and experiment prospects of the

heavy ion physics at LHCC. Kobdaj, Y. Yan and K. Khosonthongkee

School of Physics, Institute of Science

Suranaree University of Technology

28 July 2009

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Outline

Accelerators Collider types Physics quantities LHC Heavy Ion Physics Acknowledgement References

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Accelerators

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Collider typesFixed TargetColliding Beam

Electron and Positron CollidersHadron Colliders

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Fixed Target

Colliding Beam

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Advantages zero charge system, suitable for creating new particles well-understood beam properties symmetric beams between the electrons and positrons backgrounds low and well-undercontrol good precision

Disadvantages large beam radiation difficult to get a high luminosity

Electron and Positron Colliders

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Advantages high c.m. energy high luminoscity Multiple (strong, electroweak) channels

Disadvantages initial state unknown final state is difficult to read not good precision

Hadron Colliders

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Physics quantitiesThe energyThe luminosity

Cross sectionKinematic Variables

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The energy

21 2 1 22

1 2 2 21 2 1 2 1 2

( ) 0( )

2( )

E E p ps p p

m m E E p p

in the c.m. frame

1 2 1 2

1 2 2

2 2 0

2 0cm

E E p pE s

E m p

in the c.m. frame

in the fixed target frame

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a bN N and are the number of particles in each bunch.

a bN Nf n

AL

The luminosity

The luminosity is the number of particles per unit area per unit time times

n is the number of bunches in either beam around the ring

A is the cross-sectionl area of the beamf is the frequency.

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The number of interactions per unit time/ per target divided by incident flux

( ) Cross Section

d

d

Scattered fluxunit surface

Incident fluxunit of solid angle

dd

d

Differential Cross Section

The number of interactions per unit second/ per target into small solid angle  divided by incident flux

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Transverse momentum

Longitudinal momentum

Transverse mass

2 2 2x yp p p

Kinematic Variables

zp

2 2 2m p m

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Rapidity

Pseudorapidity

1ln

2z

z

E py

E p

1ln

2z

z

p p

p p

2 2 2, ,p m E p m E p

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Mandelstam variables

2 21 2 3 4

2 21 3 2 4

2 21 4 2 3

2 2 2 21 2 3 4

( ) ( )

( ) ( )

( ) ( )

s p p p p

t p p p p

u p p p p

s t u m m m m

s, t and u are Lorentz invariant quantities

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multiplicity Multiplicity is the total number of particles produce

d in a collision is the multiplicity of the collision.

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LHC

The Large Hadron Collider (LHC) is the the world's largest particle accelerator.

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LHC facts

Circumference 26.7 km Luminosity Magnet 8.33 T current 11,700A superconducting cable 7600 km superconducting magnets

1,232 dipole magnets 392 quadrupole magnets

3410 -2 -1cm s

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Temperature of 1.9 K 99.9999991% of the speed of light Period for a proton to travel once around the

main ring 90 microseconds Frequency 11,000 Hz Photon bunches 2,808 bunches The collision rate is one billion per second

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Six Detectors

A Large Ion Collider Experiment (ALICE) A Toroidal LHC ApparatuS (ATLAS) Compact Muon Solenoid (CMS) Large Hadron Collider beauty (LHCb) Large Hadron Collider forward (LHCf) Total Cross Section, Elastic Scattering and

Diffraction Dissociation(TOTEM)

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1) ALICE

Heavy Ion experiment Looks for a state called

quark-gluon plasma that existed shortly after the Big Bang.

Quark-gluon plasma is a state of matter wherein quarks and gluons are deconfined

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2) ATLAS

a general purpose detector

to look for evidence of physics beyond the standard model, such as supersymmetry, or extra dimensions

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3) CMS

a general purpose detectors

to investigate a missing piece of the Standard Model, the Higgs boson

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4) LHCb

measuring the parameters of CP violation in the interactions of b-hadrons (heavy particles containing a bottom quark)

B physics search for evidence of

antimatter

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5) LHCf

astroparticle (cosmic ray) physics simulates cosmic rays within a controlled

environment to study naturally occurring cosmic ray

collisions

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6) TOTEM

measure the size of protons the LHC's luminosity

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How to detect particles

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Detecting method

Tracking is the method to measure the direction and magnitude of charged particles momenta

Calorimeters measure particle’s energy hadron-shower calorimeters electromagnetic calorimeter

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Heavy-Ion Physics

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ALICE

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Collision Systems

pp PbPb* ArAr pPb

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muon chamber records muon tracks muons are the only charged particles that

penetrate outside the calorimeter.

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Hard Probes

hot nuclear matter open charm open beauty inclusive jet tagged jet

jet Z jet jet gamma jet

direct photon J/Psi suppression ratios of leading particles Uppsilon suppression

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References

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Papers Armesto, N et al, J. Phys. G: Nucl. Part. Phys. 35(2008)

054001. Borghini,N and Wiedemann, U.A., J. Phys. G Nucl. Part.

Phys. 35(2008) 023001. Presentations

Wyslouch, Heavy Ion Physics at the LHC:experimental prospects.

Giubellino, Heavy Ion physics at the LHC Hadron Collider Physics Symposium(HCP2008), Galena, Illinois,USA .

Han, T Collider Phenomenology Summer School on Particle Physics in the LHC Era.

Lester, C.G., Frontiers of Particle Physics. Walet, N , Nuclear and Particle Physics. Varvell, K, High Energy Physics. Thomson, M, Particle Physics.

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Books Wong, CY , Introduction to High-Energy Heavy-Ion

Collisions (World Scientific, Singapore, 1994) Kane, G, Perspectives Of LHC Physics (World

Scientific, Singapore, 2008) Vogt,R, Ultrarelativistic Heavy-Ion Collisions (Elsevier,

The Netherlands, 2007) Web

Wiki CERN HowStuffWorks LHCf CMS

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Acknowledgement

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Suranaree University of Technology The Commision on Higher Education of

Thailand CHE-RES-RG Theoretical Physics

Thailand Center of Excellence in Physics (ThEP)

National Research Council of Thailand Thai National Grid Center