Future in Particle Future in Particle Physics!Physics!

ECFA:Future of Accelerator-Based Particle Physics in

Europe

HEPAP:Long Range Planning for U.S. High-Energy Physics

ACFA:coming up soon? F. Linde, 14-December-2001, Amsterdam

Input to ECFA Input to ECFA reportreportLaboratories:

• L. Maiani: “CERN: views for the future”• A. Wagner: “Views on the future of DESY”• J. Bagger: “HEPAP sub-panel on long range planning for U.S. High energy

physics”• F. Gilman: “The U.S. high energy physics advisory panel white paper”• A. Skrinsky: “Russian HEP activity: status and perspectives”• S. Komamiya: “Report on ACFA activities”

Projects:• F. Gianotti: “Physics perspectives with the LHC within Standard Model” • P. Sphicas: “Physics perspectives with the LHC: SuSy and other physics beyond

SM”• K. Hubner: “New acceleration methods and plans for high intensity proton

machines”• R. Klanner: “Future perspectives for ep physics”• D. Miller: “Physics potential and concrete perspectives for <1 TeV linear

colliders”• P. Zerwas: “Muti-TeV lepton colliders: the physics potential”• J.P. Delahaye: “CLIC, a two beam multi-TeV e linear collider”• A. de Roeck: “CLIC, a compact linear collider: experimentation and physics

potential”• M. Tigner: “Perspectives and experimental environment of a muon collider”• P. Janot: “What physics at muon colliders”• K. Peach: “Neutrino factories”

Physics challengesPhysics challengesmany questions, e.g.:

• matter anti-matter?• dark matter?• three families?• generation of mass?• proton decay?• charge quantization?• unification?

“recent” discoveries:• three families (LEP)• t-quark discovered (Tevatron)• indirect Higgs mass (LEP/Tevatron) -oscillations (Kamiokande)• CP violation in B system (BaBar/Belle)

ProgressProgress within the Standard within the Standard ModelModel

Outstanding issues:• Higgs mechanism• quark-gluon plasma• CP violation quark sector• neutrino sector

Improvements:

• masses: mW, mt, …

• couplings: s, G, …

• other: sin2w, CKM, g-2, ...

Approaches:• Rare/forbidden decays• New particles• New interactions• Unification• Unknown: look into the

sky!

Progress beyond the Standard Progress beyond the Standard ModelModel

~~~~ 0

1

0

2

qqqqqqg

eeG

Experimental opportunitiesExperimental opportunities

Hadron-hadron (CERN & Fermilab)

– LHC upgrades: • Luminosity upgrade 1034 1035 cm-2s-1 “easy” (you want it?)• Energy upgrade difficult (we might want it!)

– Very large hadron colliders: VLHC

Lepton-lepton (CERN, DESY, US, Japan)

– ee linear colliders: TESLA, NLC, JLC, CLIC collider

Intense neutrino beams (CERN, FermiLab, Japan)

, , e, e

Future “G$” projectsFuture “G$” projects

Very large hadron colliderVery large hadron collider FermilabVLHC phased project (240 km circumference tunnel)

Issue: cost, cost and cost 10351034Lumi (cm-2s-1)

10-122B-field (T)

17530-40s (TeV)

VLHC-2VLHC-1

dipole magnets interesting

(transmission line)

PhysicsPhysics

• The unknown, new, The unknown, new, exciting!exciting!• Continuation of LHCContinuation of LHC

But also clear you only But also clear you only embark on this well after embark on this well after the LHC has cleared the the LHC has cleared the

TeV energy rangeTeV energy range

pee ee

Intense neutrino beams Intense neutrino beams (( collider?)collider?)

1. SPL: Ep 2-15 GeV, 1016 p/s

2. target: p

-decay:

-cooling: reduce E, E50 GeV

-decay: decay in “ring” -collider: future music

neutrino beam neutrino

beam

PhysicsPhysics“Near” (<1 km, high rate)

• structure functions• CKM matrix• new physics

“Far” (102-104 km, low rate)

• oscillations• CP

Japan, CERN & FermiLab

collidercolliderEverything ee linear collider offers with as advantages:

– Far less Beamstrahlung (negligible)– Far better calibration (E5 keV, energy spread &

polarization)

– Much larger couplings to Higgs bosons (/ee4104)

Higgs lineshape!

Linear eLinear eee collider: cartoons collider: cartoons

DESY

Japan

SLAC

Linear eLinear eee collider: real work collider: real work

Lepton colliders: eLepton colliders: eee

4012002.5500510001000xy (nm2)

30-4025335Length (km)

5-10

2-3

50

0.5-1.0

NLC/JLC

3-4

3-5

25-35

0.1-0.8

TESLA

?

0.0003

(10?)

0.1

SLC

10Lumi (1034 cm-2s-1)

30-40Beamstrahlung (%)

150-170Gradient (MV/m)

0.5-5.0s (TeV)

CLIC

eeee

• Higgs• Supersymmetry• lots more (QCD, …)

X-ray FEL option:• biology• material

ee and and options

Making choices!Making choices!$$$$$$$$$$$$$$$$$$$$$$

• HEP creativity exceeds available finances must be selective

• allow orginal, excellent, new, ... proposals be flexible• limit (expensive) duplications operate globally• sufficient R&D before technology decision be

economicalrealistic time schedules!accelerator non-accelerator

• links to astro-physics, cosmology and nuclear physics• “plan” for the unexpected• fill “no-physics” between large accelerator projects

Fairly well covered already• B-physics: HeraB/Tevatron - BaBar/Belle - LHCb• Heavy-ion physics: RHIC - ALICE

ECFA recommendationsECFA recommendations

• Make the LHC a success i.e. get it running timely!• Exploit ongoing facilities optimally in pre-LHC era• Stimulate accelerator R&D @ home institutes• Next project: a sub-TeV (s 400 GeV) ee linear collider

(irrespective of the findings of the LHC i.e. justification exists today)

• Coordinated R&D effort to study -storage ring(SPL intense -beam)

• VLHC, CLIC & -collider: far future i.e. beyond 2020(coordinate R&D efforts)

HEPAP additionHEPAP additionImportance of non-accelerator based

experiments

Linear eLinear eee colliders colliderspp ee colliders:

• complementary (SppS LEP Tevatron)• Z, W discovery Z factory

• mt prediction top discovery

• mH prediction Higgs discovery?

• pp: discovery physics ( Nobel exp.)• ee: precision physics ( Nobel th.)

c.m. energy s:• facts:

• “Giga Z”: smZ90 GeV

• “top factory”: s2mt350 GeV

• speculation:• “SM Higgs factory”: smH+mZ350 GeV

• new physics: super-symmetry, extra dimensions, …..

s 400 GeV

eeee linear collider: physics linear collider: physics• Precision Higgs study (mH, spin, H, HHH, Hff, …)

• Super-symmetry spectroscopy (threshold scans)• Precision measurements thereby probing higher energies• Anything new and unexpected (unlikely to escape LHC though)

eeee linear collider: Higgs linear collider: Higgs

ZHl+l-bbZHqqbb

Higgs signals

Higgs selfcoupling

HHZ

(fb)

mH

e+e- HHZ

Higgs spin

s

HZ

(fb)

e+e- HZ

Higgs decay width

Exciting non-accelerator program– proton decay, neutrino, satellite-based & gravitational wave

experiments

Develop -superbeam/factory facility– SPL: intense p source -cooling R&D – ?

Get the e+e- linear collider on track– sort out technology (cold warm)– agree upon one site (FermiLab?) & get it funded!– do the experiment(s): 2013

– better insight into …. (Higgs, supersymmetry, higher energy scales)

Prospects Prospects (limit duplications: BTeV, … !)(limit duplications: BTeV, … !)

Resolve CERN/LHC situation– management & finances– realise machine & experiments– do the experiments:

– find Higgs, supersymmetry, quark-gluon plasma, CKM & CP

?

?

NIKHEF