Relativistic Heavy IonsALICE/CERN

Kristjan GulbrandsenNiels Bohr Institute - Discovery

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QCD Phase Diagram

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CERN – The Large Hadron Collider

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Creating the Early Universe

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Nucleus Collisions

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Detecting a Collision

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A Large Ion Collider Experiment

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Time Projection Chamber (TPC)

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Measure position and momentumParticle Identification

TPC Laser

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Beam split into 336 laser tracks

Unaffected by magnetic field

Crucial for knowledge of drift time

Exact positions known

TPC PbPb Event

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Strong Hydrodynamics Asymmetry region of interaction Produces asymmetric distribution of particles

Requires interactions Can measure this final asymmetry (v2)

Related to viscosity of the medium Higher order correlations indicate hydrodynamical

behavior

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Duke – Jetlab – Cold Atomshttp://www.phy.duke.edu/research/photon/qoptics/news/stronginter/index.html

Forward Multiplicity Detector

Only detector in ALICE with high segmentation at high |η|51200 silicon strips - radial and azimuthal segmentationposition and energy informationHit information can be used in p+p for particles detectionEnergy information used in Pb+Pb (high occupancy)

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Interaction Point

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dN/dh versus hCan measure distribution of produced particlesHigh h appears to show universal behaviorMost energy goes into production of particles at midrapidity

~ 18000 particles produced in central collision, 15 GeV/fm3 energy densityFirst order measurement

higher orders can give more information

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Long Range Correlations (LRC)How much does each side of the interaction communicate?Not calculable from theoryMuch information contained about the internal dynamics

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Proton Collision Processes

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SummaryActive analysis crucial to understanding the QGPBulk properties and correlations are key topicsp-p data analyzed to gain deeper understanding of baseline

interactionsAnalyses will feed back into modelsGives understanding of initial state of Pb-Pb collisions

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Divide outinitial state

Do we understandthe initial state?

Future

p-Pb run November this year! New opportunities to study

nuclear matter in novel state(gluon saturation)

Shed light on possiblecomplication to understandingthe initial state of these collisions

Current measurement methods ready to be applied to p-Pb

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HEHI Group in 2012

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Perm. Staff:Ian BeardenHans BøggildJens Jørgen GaardhøjeBørge Svane Nielsen

Temp. Staff: Christian Holm ChristensenKris Gulbrandsen

PostDocs: Ante Bilandzic (from 2/2) Marek Chojnacki (from 7/5)Hans Hjersing DalsgaardCasper Nygaard (to 30/6)

Ph. D. students: Alexander HansenCarsten Søgaard (to 30/6)Valentina Zaccolo

Undergradstudents: Leire ArriolaPeter JochumzsenBastian PoulsenThomas Schwanberger

Techn.& Eng.:Henrik BertelsenAksel BoiesenJimmy K. HansenJørn Westergaard

Funded By:-Danish Natural Science Research Council(FNU)-Danish Basic Research Foundation (GF)-Carlsberg Foundation

Backup Slides

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TPC Momentum Resolution

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