Dean Karlen University of Victoria & TRIUMF IPP Town Hall ...karlen/talks/lc/ipplrp05_karlen.pdf ·...

Dean KarlenUniversity of Victoria & TRIUMF

IPP Town Hall MeetingJune 4, 2005, TRIUMF

June 4, 2005June 4, 2005 The International Linear Collider / IPP Town Hall MeetingThe International Linear Collider / IPP Town Hall Meeting 33

The International Linear ColliderThe International Linear Collider

Next in the line of Next in the line of ee++ee-- colliderscolliders at the high at the high energy frontier of particle physicsenergy frontier of particle physics

SLAC/SLC

CERN/LEP


year

1980 1990 2000 2010 2020 2030

Cen

tre-o

f-mas

s en

ergy

(GeV

)

100

1000PETRAPEPTRISTANSLCLEP - ILEP - IIILCILC - II

ee++ee−− colliderscolliders at the frontierat the frontier

Z0 threshold

W+W− threshold

tt thresholdHZ0 threshold?

dark matter threshold?


Why Linear?Why Linear?

Centre-of-mass Energy (GeV)

0 100 200 300 400 500 600

Circ

umfe

renc

e / L

engt

h (k

m)

0

10

20

30

40

50

60

$

circular colliders

linear colliders

2ER ∝

EL ∝

A circular 500 GeVmachine would be170 km around andconsume 45 GW


““Energy FrontierEnergy Frontier”” Particle PhysicsParticle Physics

Increasing the collision energy allows for new Increasing the collision energy allows for new fundamental processes to be observed and probes fundamental processes to be observed and probes matter and space at smaller distance scalesmatter and space at smaller distance scales

precision measurements sensitive to mass scales well above precision measurements sensitive to mass scales well above √√ss

The two main energy frontier tools in the past three The two main energy frontier tools in the past three decades: proton decades: proton colliderscolliders and electron and electron colliderscolliders

protons are more easily accelerated to high energies because protons are more easily accelerated to high energies because they radiate less synchrotron radiation in a circular acceleratothey radiate less synchrotron radiation in a circular acceleratorrelectron interactions are more easily studied because the initiaelectron interactions are more easily studied because the initial l state is simplerstate is simplerboth tools have been essential to advance our knowledge of both tools have been essential to advance our knowledge of fundamental physics:fundamental physics:

discoveries of new phenomenadiscoveries of new phenomenatesting models that account for these phenomenatesting models that account for these phenomena


Interplay of proton and electron Interplay of proton and electron colliderscolliders

proton proton colliderscolliders electron electron colliderscolliders1980’s: SppS• discovery of the Z0, W+, W−

1990’s: LEP/SLC• detailed investigation

of Z0, W+, W− production• indirect influence of top

quark – definitive predictionof its mass

• indirect influence of Higgsboson – mass estimated

2010’s: ILC• detailed study of the Higgs• detailed study of dark matter

2000’s: LHC• discovery of the Higgs boson?• discovery of the dark matter

particle?

1990’s: Tevatron• discovery of the top quark


Linear Collider Physics: ILinear Collider Physics: IThe electromagnetic and weak forces are now known to The electromagnetic and weak forces are now known to arise from a unifying symmetry in naturearise from a unifying symmetry in nature

most precisely demonstrated by the LEP/SLC experimentsmost precisely demonstrated by the LEP/SLC experiments

The symmetry between the electromagnetic and weak The symmetry between the electromagnetic and weak forces is broken (weak bosons are heavy)forces is broken (weak bosons are heavy)

The Higgs model is an ad hoc component of the Standard Model The Higgs model is an ad hoc component of the Standard Model that accounts for the broken symmetry that accounts for the broken symmetry –– does not explain whydoes not explain why

it works for low energy processes but falls apart at high it works for low energy processes but falls apart at high energiesenergies

the model predicts that a new particle exists (the Higgs the model predicts that a new particle exists (the Higgs boson) with definite propertiesboson) with definite properties

the ILC will be able to make a large variety of precision the ILC will be able to make a large variety of precision measurements that will provide critical data to understand measurements that will provide critical data to understand the real nature of electroweak symmetry breakingthe real nature of electroweak symmetry breaking


The golden processesThe golden processes

At LEP, the golden processes for studying the At LEP, the golden processes for studying the electroweak sector were:electroweak sector were:

At the ILC, the golden processes for At the ILC, the golden processes for studying the Higgs sector are:studying the Higgs sector are:

LEP beam energies were not sufficiently high enough LEP beam energies were not sufficiently high enough for these process to occurfor these process to occur

0Zee →−+ −+−+ → WWee

HZee 0→−+

νν→−+ Hee


Higgs production at a LCHiggs production at a LC


Linear Collider Physics: IILinear Collider Physics: II

From astrophysical observations, it appears that From astrophysical observations, it appears that ~25% of the Universe is ~25% of the Universe is ““Dark MatterDark Matter””

neutral, stable, cold (massive), nonneutral, stable, cold (massive), non--baryonicbaryonicnew physics new physics –– a new (conserved) quantum number?a new (conserved) quantum number?production and detection of dark matter particles at production and detection of dark matter particles at future future colliderscolliders would be very exciting!would be very exciting!

One possible explanation: One possible explanation: supersymmetrysupersymmetrynot developed specifically to solve the DM problem!not developed specifically to solve the DM problem!the LSP is an excellent candidate for DMthe LSP is an excellent candidate for DM


Dark Matter at the ILC?Dark Matter at the ILC?

There are strong hints that dark matter could be There are strong hints that dark matter could be produced at the ILCproduced at the ILC

SUSY favours SUSY favours sparticlesparticle masses below ~ 1 masses below ~ 1 TeVTeVThe dark matter density is consistent with a neutral The dark matter density is consistent with a neutral particle having particle having ““weakweak”” strength couplingsstrength couplings

The LHC has the best chance to discover The LHC has the best chance to discover strongly interacting strongly interacting sparticlessparticles ((gluinosgluinos, , squarkssquarks))

challenging study at LHC: initial state is not well challenging study at LHC: initial state is not well known, final state involves a cascade of known, final state involves a cascade of sparticlesparticledecays, with at least two massive invisible particlesdecays, with at least two massive invisible particles

ILC can study the weakly interacting ILC can study the weakly interacting sparticlessparticlesLHC+ILC data can LHC+ILC data can ““predictpredict”” DM relic density DM relic density


ILC/LHC ILC/LHC complementaritycomplementarity

Well documented study underway:Well documented study underway:LHC/ILC Study Group:LHC/ILC Study Group:

http://www.ippp.dur.ac.uk/~georg/lhclc/http://www.ippp.dur.ac.uk/~georg/lhclc/Recent document:Recent document:

““Physics Interplay of the LHC and the ILCPhysics Interplay of the LHC and the ILC””hephep--ph / 0410364ph / 0410364470 pages:470 pages:

all cases: ILC + LHC data complementaryall cases: ILC + LHC data complementary

• Higgs Physics• Strong Electroweak Symmetry Breaking• Supersymmetric Models• Electroweak and QCD Precision Physics• New Gauge Theories• Models with Extra Dimensions

http://www.ippp.dur.ac.uk/~georg/lhclc/


Consensus in the HEP communityConsensus in the HEP community

Given the broad range of fundamental physics Given the broad range of fundamental physics questions that it addresses, the HEP community questions that it addresses, the HEP community sees the ILC to be the next step that is needed sees the ILC to be the next step that is needed to advance the fieldto advance the field

over 2700 particle physicists have signed a document over 2700 particle physicists have signed a document supporting the physics potential of the ILCsupporting the physics potential of the ILCthe US DOE places the ILC as the top priority for midthe US DOE places the ILC as the top priority for mid--term new facilities term new facilities committees for future accelerators (ICFA,ACFA,ECFA) committees for future accelerators (ICFA,ACFA,ECFA) also put the ILC as their first priorityalso put the ILC as their first priority


Building the ILCBuilding the ILC

Over the past decade, significant effort has gone Over the past decade, significant effort has gone into the necessary R&D to design a linear into the necessary R&D to design a linear collider to reach the required specifications:collider to reach the required specifications:

Centre of mass energy: 500 Centre of mass energy: 500 GeVGeV –– 1000 1000 GeVGeVrequires RF cavities with a large accelerating requires RF cavities with a large accelerating gradient (>30 gradient (>30 MeV/mMeV/m))

Luminosity: > 10Luminosity: > 103434 cmcm−−2 2 ss−−11

requires large numbers of electrons (> 10requires large numbers of electrons (> 101010) ) packed into very small bunches (< 500 x 5 nmpacked into very small bunches (< 500 x 5 nm22) ) brought into collision at high rate (> 10brought into collision at high rate (> 1044 ss−−11))


Building the ILCBuilding the ILC

Two complete designs were prepared that met Two complete designs were prepared that met these requirementsthese requirements

the key feature distinguishing them was the nature of the key feature distinguishing them was the nature of the RF accelerating cavities:the RF accelerating cavities:

US + Japan US + Japan –– high frequency, room temperaturehigh frequency, room temperatureGermany Germany –– lower frequency, superconductinglower frequency, superconducting

international technical review found both suitableinternational technical review found both suitable

In 2004, the International Technical In 2004, the International Technical Recommendation Panel selected the Recommendation Panel selected the superconducting optionsuperconducting option

the worldthe world’’s labs now working towards a single designs labs now working towards a single design


Superconducting accelerator cavitiesSuperconducting accelerator cavities


Possible Tunnel LayoutPossible Tunnel Layout

Need a 30 km tunnel to reach energy goalNeed a 30 km tunnel to reach energy goal


Damping ring R&DDamping ring R&D

ATF facility in Japan hasATF facility in Japan hasdemonstrated necessarydemonstrated necessaryreduction in reduction in emittanceemittance


Final focus R&DFinal focus R&D


Linear collider detector conceptsLinear collider detector concepts

LDC

SiD

GLD

LDC: start from TESLA designCoordinators:• Ties Benke: Germany• Henri Videau: France• Marco Battaglia: USA• Dean Karlen: Canada• Bob Hsiung: Taiwan• Yasuhiro Sugimoto: JapanSee: www.ilcldc.org

http://www.tiscali.co.uk/reference/encyclopaedia/countryfacts/images/flags/large/c04973.gif


Linear collider detector challengesLinear collider detector challenges

Compared to the LHC, the ILC environment is Compared to the LHC, the ILC environment is much less severe, but the performance much less severe, but the performance requirements are much more demanding:requirements are much more demanding:

VertexingVertexing: : σσipip ~ 5 ~ 5 μμm m ⊕⊕ 5 5 μμm/(p sinm/(p sin3/23/2 θθ))1/5 1/5 rrbeampipebeampipe, 1/30 pixel area, 1/30 thickness c.f. LHC, 1/30 pixel area, 1/30 thickness c.f. LHC

Tracking: Tracking: σσ(1/p(1/ptt) ~ 5 ) ~ 5 ××1010--55 GeVGeV--11

1/10 of LHC. 1/6 material in tracking volume1/10 of LHC. 1/6 material in tracking volume

CalorimetryCalorimetry: : σσEE ~ 0.3 ~ 0.3 √√EE1/200 granularity of calorimeter c.f. LHC1/200 granularity of calorimeter c.f. LHC

1/3 SLD

1/10 LEP

1/2 LEP


Vertex detectorVertex detector

Precise Precise SiSi pixel detectors near the collision point pixel detectors near the collision point to detect the displaced vertex of particles coming to detect the displaced vertex of particles coming from the decay of a particle with a very short lifetime from the decay of a particle with a very short lifetime (less than 10(less than 10−−1212 s)s)

examples: charm, bottom quarks, examples: charm, bottom quarks, tautau leptonsleptons


Tracking detectorTracking detector


Tracking challengeTracking challenge

Example: Higgs recoil massExample: Higgs recoil mass

σ(1/pt) ~ 5 ×10-5 GeV-1

is necessary!


Tracking technologyTracking technology

Two technologies considered: Two technologies considered: SiSi (few precise (few precise measuring layers) or gas (continuous) measuring layers) or gas (continuous) Gas tracker: Time projection chamberGas tracker: Time projection chamber

to achieve resolution goal requires an advance to achieve resolution goal requires an advance in TPC technologyin TPC technologyCanadian groupsCanadian groupshave made bighave made bigadvances towardsadvances towardsthis goalthis goal……


LC TPC R&D in CanadaLC TPC R&D in Canada

Prototype Prototype TPCsTPCs built to use MPGD readout:built to use MPGD readout:Carleton/Montreal group has Carleton/Montreal group has pioneered the method of charge pioneered the method of charge dispersion with a resistive anode dispersion with a resistive anode for GEM and for GEM and MicromegasMicromegas TPC TPC readoutreadoutVictoria group has operated Victoria group has operated a GEMa GEM--TPC in magnetic TPC in magnetic fields up to 5 Tfields up to 5 Tboth prototypes have both prototypes have demonstrated significantly demonstrated significantly better resolution as compared to traditional better resolution as compared to traditional TPCsTPCssee presentations on Wednesday at CAP congresssee presentations on Wednesday at CAP congress


Future plans for LC TPC R&D in CanadaFuture plans for LC TPC R&D in Canada

The Canadian group plans to The Canadian group plans to participate in test beam studies at KEK and DESYparticipate in test beam studies at KEK and DESYparticipate in the design and construction of a large participate in the design and construction of a large scale prototype in collaboration with other groups scale prototype in collaboration with other groups from around the worldfrom around the world

how to segment and tile how to segment and tile MPGDsMPGDs on a large on a large endplate?endplate?

perform simulation studies to answer questions perform simulation studies to answer questions arising in the detector conceptsarising in the detector concepts

pattern recognition in jetspattern recognition in jetshow well can nonhow well can non--uniform magnetic fields be uniform magnetic fields be determined and corrected for? determined and corrected for?


CalorimeterCalorimeter


Jet Energy Resolution RequirementsJet Energy Resolution Requirements

Goal: distinguish W and Z when they decay into quarksGoal: distinguish W and Z when they decay into quarksrequires excellent jet energy resolution, requires excellent jet energy resolution, σσEE ~ 30% ~ 30% √√EE

, νννν ZZeeWWee →→ −+−+example:

E%30E%60


Calorimeter technologyCalorimeter technology

To reach goal requires narrow showers and fine To reach goal requires narrow showers and fine segmentation: ECAL: segmentation: ECAL: Si+WSi+W HCAL: HCAL: SS+ScintSS+Scint??

Iron Tungsten


LC LC CalorimetryCalorimetry R&D in CanadaR&D in Canada

Canadian group is just starting to join existing Canadian group is just starting to join existing LC calorimeter efforts:LC calorimeter efforts:

Regina group has experience with Regina group has experience with SiPMSiPM readout readout ––very attractive option for HCAL readoutvery attractive option for HCAL readoutMcGill group to participate in test beam studies of McGill group to participate in test beam studies of prototype calorimeter systems (CALICE collaboration) prototype calorimeter systems (CALICE collaboration)


Bringing the ILC into realityBringing the ILC into reality

An international structure has been set up to An international structure has been set up to complete the global design of the ILCcomplete the global design of the ILC

Leader of the Global Design Effort: Barry Leader of the Global Design Effort: Barry BarishBarish

ILCSC

GlobalDesignEffort

Asia Regional Team

N. American Regional Team

EuropeanRegional Team

Participating Labsand Universities




ILC timescaleILC timescale2005:2005:

GDE put togetherGDE put togetherDetector concept groups in formationDetector concept groups in formation

2006:2006:GDE to prepare the ILC Conceptual DesignGDE to prepare the ILC Conceptual DesignDetector concept groups to prepare Detector concept groups to prepare ““detector outlinesdetector outlines””

2007/8:2007/8:GDE to complete the ILC Technical DesignGDE to complete the ILC Technical DesignDetector concepts complete Conceptual DesignsDetector concepts complete Conceptual Designs

2008/9:2008/9:Site selection, government approvals, begin constructionSite selection, government approvals, begin constructionDetector collaborations formDetector collaborations form

2015?:2015?:earliest start of experimental programearliest start of experimental program


Next stepsNext steps

Later this summer, a twoLater this summer, a twoweek workshop is beingweek workshop is beingheld at Snowmassheld at Snowmass

finalize baseline accelerator parameters for CDRfinalize baseline accelerator parameters for CDRstrong focus on detector concept studiesstrong focus on detector concept studies450 registered already450 registered alreadya good opportunity for newcomers to join the efforta good opportunity for newcomers to join the effort


Canadian planningCanadian planning

Canadian ILC R&D funded through NSERC Canadian ILC R&D funded through NSERC discovery grantsdiscovery grants

egeg. 5 grantees on last TPC request (2004). 5 grantees on last TPC request (2004)

Travel to ILC workshops have been supported Travel to ILC workshops have been supported through IOF grantsthrough IOF grants

14 grantees on last request (2002)14 grantees on last request (2002)

Nucleus of Canadian group is meeting to plan Nucleus of Canadian group is meeting to plan for future ILC activity:for future ILC activity:

Montreal / McGill / Carleton / Toronto / Regina / Montreal / McGill / Carleton / Toronto / Regina / UBC / VictoriaUBC / VictoriaNext meeting: June 6, 5:15pm, room: CEME 1202Next meeting: June 6, 5:15pm, room: CEME 1202(follows PPD session) All are welcome(follows PPD session) All are welcome


SummarySummary

The physics case for a Linear Collider is very The physics case for a Linear Collider is very compellingcompellingThe technologies for the machine and the The technologies for the machine and the experiments are in handexperiments are in handThe international HEP community is solidly The international HEP community is solidly behind the project and is working together to behind the project and is working together to bring it to realitybring it to realityTo ensure a strong future for particle physics in To ensure a strong future for particle physics in Canada, it is important for us to participate in Canada, it is important for us to participate in this projectthis project

Please join us. For more information see:Please join us. For more information see:www.linearcollider.orgwww.linearcollider.org www.linearcollider.cawww.linearcollider.ca

Dean Karlen University of Victoria & TRIUMF IPP Town Hall ...karlen/talks/lc/ipplrp05_karlen.pdf ·...

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