Physics Impact
of
The Linear Collider
Philip Burrows
John Adams Institute, Oxford University
Philip Burrows
1
SLAC Summer Institute 5/08/09
Outline
• General motivation
• Electron-positron collisions
• Linear Collider physics overview
• Accelerator issues
• Linear Collider status
• Outlook
Philip Burrows
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SLAC Summer Institute 5/08/09
Revealing the origin of the universe
Big Bang
now
Older ….. larger … colder ….less energetic
Philip Burrows
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SLAC Summer Institute 5/08/09
Telescopes to the early universe
Big Bang
now
Older ….. larger … colder ….less energetic
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SLAC Summer Institute 5/08/09
Particle Physics Periodic Table
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SLAC Summer Institute 5/08/09
Profound Questions
• Why do the particles all have different masses,
and where does the mass come from?
Philip Burrows
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SLAC Summer Institute 5/08/09
Profound Questions
• Why do the particles all have different masses,
and where does the mass come from?
• Why are the building blocks fermions and the
force carriers bosons?
Philip Burrows
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SLAC Summer Institute 5/08/09
Profound Questions
• Why do the particles all have different masses,
and where does the mass come from?
• Why are the building blocks fermions and the
force carriers bosons?
• Why are there 3 forces? (+ gravity!)
Philip Burrows
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SLAC Summer Institute 5/08/09
Profound Questions
• Why do the particles all have different masses,
and where does the mass come from?
• Why are the building blocks fermions and the
force carriers bosons?
• Why are there 3 forces? (+ gravity!)
• Why are there 3 generations of building blocks?
Philip Burrows
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SLAC Summer Institute 5/08/09
Profound Questions
• Why do the particles all have different masses,
and where does the mass come from?
• Why are the building blocks fermions and the
force carriers bosons?
• Why are there 3 forces? (+ gravity!)
• Why are there 3 generations of building blocks?
• Where did all the antimatter go?
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SLAC Summer Institute 5/08/09
Composition of the universe
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SLAC Summer Institute 5/08/09
Composition of the universe
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SLAC Summer Institute 5/08/09
More Profound Questions
• Why is only 4% of universe atomic matter?
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SLAC Summer Institute 5/08/09
More Profound Questions
• Why is only 4% of universe atomic matter?
• What is the 23% dark matter content made of?
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SLAC Summer Institute 5/08/09
Even More Profound Questions
• Why is only 4% of universe atomic matter?
• What is the 23% dark matter content made of?
• What is the 73% ‘dark energy’?
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SLAC Summer Institute 5/08/09
Large Hadron Collider (LHC)
collide
proton
beams
of 7 TeV
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SLAC Summer Institute 5/08/09
ICFA Statement on LC (1999)
‘To explore and characterize fully the new physics
that must exist will require the Large Hadron
Collider plus an electron-positron collider with
energy in the TeV range.
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SLAC Summer Institute 5/08/09
ICFA Statement on LC (1999)
‘To explore and characterize fully the new physics
that must exist will require the Large Hadron
Collider plus an electron-positron collider with
energy in the TeV range.
Just as our present understanding of the physics
at the highest energy depends critically on
combining results from LEP, SLC, and the
Tevatron, a full understanding of new physics
seen in the future will need both types of highenergy probes.’
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SLAC Summer Institute 5/08/09
e+e- colliders
• Produce annihilations of point-like particles under
controlled conditions:
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SLAC Summer Institute 5/08/09
e+e- annihilations
E
g/
E
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SLAC Summer Institute 5/08/09
e+e- colliders
• Produce annihilations of point-like particles under
controlled conditions:
well defined centre of mass energy: 2E
Philip Burrows
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SLAC Summer Institute 5/08/09
e+e- colliders
• Produce annihilations of point-like particles under
controlled conditions:
well defined centre of mass energy: 2E
complete control of event kinematics:
p = 0, M = 2E
Philip Burrows
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SLAC Summer Institute 5/08/09
e+e- colliders
• Produce annihilations of point-like particles under
controlled conditions:
well defined centre of mass energy: 2E
complete control of event kinematics:
p = 0, M = 2E
highly polarised beam(s)
Philip Burrows
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SLAC Summer Institute 5/08/09
e+e- annihilations
L or R
g/
L or R
Philip Burrows
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SLAC Summer Institute 5/08/09
e+e- colliders
• Produce annihilations of point-like particles under
controlled conditions:
well defined centre of mass energy: 2E
complete control of event kinematics:
p = 0, M = 2E
highly polarised beam(s)
clean experimental environment
Philip Burrows
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SLAC Summer Institute 5/08/09
e+e- colliders
• Produce annihilations of point-like particles under
controlled conditions:
well defined centre of mass energy: 2E
complete control of event kinematics: p = 0, M = 2E
highly polarised beam(s)
clean experimental environment
• Give us a precision microscope:
masses, decay-modes, couplings, spins,
handedness, CP properties … of new particles
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SLAC Summer Institute 5/08/09
e+e- annihilations
E
g/
E
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SLAC Summer Institute 5/08/09
e+e- annihilations
2E > 160 GeV
E
g/
E
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SLAC Summer Institute 5/08/09
e+e- annihilations
2E > 182 GeV
E
g/
E
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SLAC Summer Institute 5/08/09
e+e- annihilations
2E > 350 GeV
E
g/
E
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SLAC Summer Institute 5/08/09
e+e- annihilations
E
E
2E > 210 GeV
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SLAC Summer Institute 5/08/09
ZH event signatures
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SLAC Summer Institute 5/08/09
Higgs mass measurement
Recoil mass:
- independent of
Higgs decay
Discovery mode
for ‘H’ decay to
weakly-interacting
particles
(TESLA TDR)
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SLAC Summer Institute 5/08/09
The Higgs Boson: profile
Determine ‘Higgs profile’:
•
Mass
•
Width
•
Spin
•
CP nature
•
Coupling to fermions ~ m
•
Coupling to gauge bosons ~ M**2
•
Yukawa coupling to top quark
•
Self coupling  Higgs potential
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SLAC Summer Institute 5/08/09
Higgs spin determination
Rise of
cross-section
near threshold
(TESLA TDR)
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SLAC Summer Institute 5/08/09
Higgs branching ratios determination
High
precision
silicon
VXD
(TESLA TDR)
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SLAC Summer Institute 5/08/09
Higgs self-coupling determination
(Nomerotski)
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SLAC Summer Institute 5/08/09
Higgs Boson profile
•
•
Mass
Width
50 MeV
4-13%
•
Coupling to fermions: bottom
0.02
•
charm
0.10
tau
0.05
Coupling to gauge bosons: W
Z0
0.02
0.01
•
Yukawa coupling to top quark
0.06
•
Self coupling
<20%
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SLAC Summer Institute 5/08/09
Higgs coupling map
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SLAC Summer Institute 5/08/09
Determining the Higgs nature
2HDM/MSSM
Zivkovic et al
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SLAC Summer Institute 5/08/09
Supersymmetry
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SLAC Summer Institute 5/08/09
e+e- annihilations
E
g/
E
2E > 280 GeV
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SLAC Summer Institute 5/08/09
e+e- annihilations
E
g/
E
2E > 440 GeV
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SLAC Summer Institute 5/08/09
e+e- annihilations
E
g/
E
2E > 460 GeV
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SLAC Summer Institute 5/08/09
Is it really Supersymmetry? …
•
Does every SM particle have a superpartner?
•
If so, do their spins differ by 1/2?
•
Are their gauge quantum numbers the same?
•
Are their couplings identical?
•
Do they satisfy the SUSY mass relations?
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SLAC Summer Institute 5/08/09
…and if so, how is SUSY broken?
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SLAC Summer Institute 5/08/09
… and furthermore
•
what are the values of the 105 (or more)
parameters?
•
is the lightest SUSY particle the neutralino?
or the stau? the sneutrino? the gravitino?
•
does SUSY give the right amount of dark
matter?
Philip Burrows
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SLAC Summer Institute 5/08/09
SUSY Decay Chains
Reconstruction of heavier
particles depends on
knowledge of mass of LSP:
Cascade decay chains,
end with LSP, eg:
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SLAC Summer Institute 5/08/09
Neutralino production
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SLAC Summer Institute 5/08/09
Neutralino production
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SLAC Summer Institute 5/08/09
Chargino production
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SLAC Summer Institute 5/08/09
Precision on SUSY Mass Measurements
mSUGRA ‘SPS1a’ parameters:
particle
mass(GeV)
h0
109
A0
359
chi_1+
133
chi_1
73
snu_e
233
e_1
217
snu_tau
214
stau_1
154
u_1
466
t_1
377
gluino
470
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LHC
0.2
3
3
3
3
3
3
3
10
10
10
LHC + LC
0.05
1.5
0.11
0.15
0.1
0.15
0.8
0.7
3
3
10
SLAC Summer Institute 5/08/09
SUSY and dark matter
Would tell us not
just neutralinos!
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SLAC Summer Institute 5/08/09
Beam polarisation  handedness
-1
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0
54
1
SLAC Summer Institute 5/08/09
Importance of beam polarisation
-1
Philip Burrows
0
55
1
P
SLAC Summer Institute 5/08/09
Spins from angular distributions
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SLAC Summer Institute 5/08/09
International Linear Collider (ILC)
31 km
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SLAC Summer Institute 5/08/09
SLAC Linear Collider
Philip Burrows
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SLAC Summer Institute 5/08/09
ILC performance specifications
ICFA – ILCSC parameters study:
• 200 < E < 500 GeV
• Energy scan capability
• Energy stability, and precision measurement,
< 0.1%
• e- polarisation > 80%
• L ~ 500 fb-1 in 4 years
• Upgrade capability to 1 TeV
• (e+ polarisation desirable)
Philip Burrows
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SLAC Summer Institute 5/08/09
ILC superconducting RF cavity
- Achieve high gradient (35MV/m); develop multiple
vendors; make cost effective, etc
- Focus is on high gradient; production yields; cryogenic
losses; radiation; system performance
Philip Burrows
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SLAC Summer Institute 5/08/09
ILC Main Linac RF Overview
560 RF units each one composed of:
• 1 Bouncer type modulator
• 1 Multibeam klystron (10 MW, 1.6 ms)
• 3 Cryostats (9+8+9 = 26 cavities)
• 1 Quadrupole at the center
Total of 1680 cryomodules and 14 560 SC RF cavities
Delahaye
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SLAC Summer Institute 5/08/09
Global SCRF Technology
TRIUMF, Canada


Cornell
JLAB


FNAL, ANL
SLAC
STFC
DESY
IHEP, China
KEK, Japan


 INFN Milan

BARC, RRCAT India

LAL
Saclay
Emerging SRF
N. Walker - ILC08
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SLAC Summer Institute 5/08/09
62
European X-FEL at DESY
3.4km
Delahaye
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SLAC Summer Institute 5/08/09
ILC beam parameters
ILC
Electrons/bunch
0.75
Bunches/train
2820
Train repetition rate
10**10
5
Hz
Bunch separation
308
ns
Train length
868
us
Horizontal IP beam size
655
nm
6
nm
300
um
Vertical IP beam size
Longitudinal IP beam size
Luminosity
Philip Burrows
2
64
10**34
SLAC Summer Institute 5/08/09
Reference Design Report (Feb 2007)
Physics
at the
ILC
Executive
Summary
700 authors,
84 institutes
Accelerator
Philip Burrows
Detectors
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SLAC Summer Institute 5/08/09
www.linearcollider.org
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SLAC Summer Institute 5/08/09
ILC timeline
2005 2006
2007 2008 2009
2010 2011
2012 2013
Reference Design Report (RDR)
GDE process
Tech. Design Phase (TDP) 1
TDP 2
LHC physics
Ready for Project
Submission
Philip Burrows
N. Walker - ILC08
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SLAC Summer Institute 5/08/09
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ILC Detectors
3 Detector Concept groups:
SiD, ILD, 4th Concept
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SLAC Summer Institute 5/08/09
The SiD Detector Concept
ECAL
Vertex
Detector
HCAL
Tracker
Solenoid
Flux Return and
Muon chambers
69
Detector specifications
Designed for precision measurements:
• Large B-field: 3-5 Tesla
• Vertex detector:
O(1B) Si pixels, 4um spatial resolution
• Tracker:
momentum resolution < 5 x 10-5
• Calorimetry:
O(100M) channels (EM)
particle-flow (PFA) approach: W + Z i.d.
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SLAC Summer Institute 5/08/09
LHC
• Is there a Higgs boson that generates mass?
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SLAC Summer Institute 5/08/09
LHC and LC
• Is there a Higgs boson that generates mass?
is it consistent with Standard Model?
is it a SUSY Higgs?
Philip Burrows
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SLAC Summer Institute 5/08/09
LHC
• Is there a Higgs boson that generates mass?
is it consistent with Standard Model?
• Is Supersymmetry realised in nature?
Philip Burrows
73
SLAC Summer Institute 5/08/09
LHC and LC
• Is there a Higgs boson that generates mass?
is it consistent with Standard Model?
• Is Supersymmetry realised in nature?
what is the mechanism of SUSY breaking?
can the lightest SUSY particle account for
dark matter?
Philip Burrows
74
SLAC Summer Institute 5/08/09
LHC
• Is there a Higgs boson that generates mass?
is it consistent with Standard Model?
• Is Supersymmetry realised in nature?
what is the mechanism of SUSY breaking?
can the lightest SUSY particle account for
dark matter?
• Are there extra spatial dimensions in nature?
Philip Burrows
75
SLAC Summer Institute 5/08/09
LHC and LC
• Is there a Higgs boson that generates mass?
is it consistent with Standard Model?
• Is Supersymmetry realised in nature?
what is the mechanism of SUSY breaking?
can the lightest SUSY particle account for
dark matter?
• Are there extra spatial dimensions in nature?
how many are there and what is their scale?
Philip Burrows
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SLAC Summer Institute 5/08/09
Manifestation of extra dimensions
Kaluza-
Klein
resonances
Weiglein
Philip Burrows
77
SLAC Summer Institute 5/08/09
LHC
• Is there a Higgs boson that generates mass?
is it consistent with Standard Model?
• Is Supersymmetry realised in nature?
what is the mechanism of SUSY breaking?
can the lightest SUSY particle account for
dark matter?
• Are there extra spatial dimensions in nature?
how many are there and what is their scale?
• Are the forces of nature unified?
Philip Burrows
78
SLAC Summer Institute 5/08/09
LHC and LC
• Is there a Higgs boson that generates mass?
is it consistent with Standard Model?
• Is Supersymmetry realised in nature?
what is the mechanism of SUSY breaking?
can the lightest SUSY particle account for
dark matter?
• Are there extra spatial dimensions in nature?
how many are there and what is their scale?
• Are the forces of nature unified?
at what energy scale?
Philip Burrows
79
SLAC Summer Institute 5/08/09
Extra material follows
Philip Burrows
80
SLAC Summer Institute 5/08/09
CLIC – basic features
• High acceleration gradient: > 100 MV/m
–
–
CLIC TUNNEL
CROSS-SECTION
“Compact” collider – total length < 50 km at 3
TeV
Normal conducting acceleration structures at
high frequency
Novel Two-Beam Acceleration Scheme
–
–
–
Cost effective, reliable, efficient
Simple tunnel, no active elements
Modular, easy energy upgrade in stages
QUAD
QUAD
POWER EXTRACTION
STRUCTURE
12 GHz – 140 MW
ACCELERATING
STRUCTURES
Main beam – 1 A, 200 ns
from
9 GeV
to 1.5 TeV
Philip
Burrows
4.5 m diameter
Drive beam - 95 A, 300 ns
from 2.4 GeV to 240 MeV
Delahaye
81
BPM
SLAC Summer Institute 5/08/09
CLIC Layout 3 TeV
(not to scale)
Drive Beam
Generation Complex
Main Beam
Generation Complex
Delahaye
Philip Burrows
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SLAC Summer Institute 5/08/09
Delahaye
CLIC Two Beam Module
Transfer lines
20760 modules (2 meters long)
71460 power production structures PETS
Drive Beam
(drive beam)
143010 accelerating structures
Philip Burrows (main
beam)
Main Beam
EPAC 2008 CLIC / CTF3
83 G.Geschonke, CERN SLAC Summer Institute 5/08/0983
Delahaye
Nominal performance of Accelerating Structures
Design@CERN, Built/Tested @KEK, SLAC
10
BKD Rate for 230ns
-4
BKD Rate: 1/pulse/m
SLAC
10
-5
500hrs
900hrs
250hrs
10
-6
1200hrs
BDR_252nsec
BDR(ACC)
0.0001
090411-090414
KEK
090403-090407
10-5
10
-7
95
CLIC
target
100
105
110
Unloaded Gradient: MV/m
115
BDR(ACC)
090402-090403
090401-090402
090227-090305
090313-090323
10-6
090501-090507
Eacc are a little shifted artificilally
to show error bars clearly
y = 3.0827e-19 * e^(0.28174x)
-7
10
80
85
90
95
100
105
110
115
120
Philip Burrows
84
Eacc
R= 0.99488
SLAC Summer Institute 5/08/09
Beam parameters
ILC (500)
CLIC (3 TeV)
Electrons/bunch
0.75
0.37
Bunches/train
2820
312
5
50
Hz
Bunch separation
308
0.5
ns
Train length
868
0.156
us
Horizontal IP beam size
655
45
nm
6
0.9
nm
300
45
um
2
6
10**34
Train repetition rate
Vertical IP beam size
Longitudinal IP beam size
Luminosity
Philip Burrows
85
10**10
SLAC Summer Institute 5/08/09
Current Experimental Situation
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SLAC Summer Institute 5/08/09
Current Experimental Situation
mH = 90 +36-27 GeV
114 < mH < 163 GeV (95% c.l.)
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SLAC Summer Institute 5/08/09
Top-Higgs Yukawa Coupling (LC)
8-jet final state
containing 4 b-jets
(Auguste Besson)
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SLAC Summer Institute 5/08/09
Higgs boson: W vs. top couplings
(TESLA TDR)
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SLAC Summer Institute 5/08/09
Higgs Boson: Fermion Couplings
Bottom vs. tau
Bottom vs. charm
(TESLA TDR)
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SLAC Summer Institute 5/08/09
Extrapolation to GUT scale: LHC only
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SLAC Summer Institute 5/08/09
Extrapolation to GUT scale: LHC +LC
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SLAC Summer Institute 5/08/09
Primordial SUSY Mass Parameters
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SLAC Summer Institute 5/08/09
Extrapolation of mSUGRA and GMSB
mSUGRA
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GMSB
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SLAC Summer Institute 5/08/09