W. Morse May 15, 2007 1

Colliding 5nm Beams at the International Linear Collider

William Morse

Brookhaven National Lab

W. Morse May 15, 2007 2

Outline of the Talk• International Linear Collider• See: “Physics Opportunities with a TeV Linear

Collider”, Sally Dawson and Mark Oreglia, Ann. Rev. Nucl. Part. Sci. 54:269 (2004),

• “Linear Collider Physics in the New Millennium”, A. Soni et al., World Sci. (2005)

• Colliding 5nm e+e- beams

W. Morse May 15, 2007 3

High Energy Colliders

Collider Particle Ecm (TeV)

Years Lum (cm-2s-1)

Tevatron

(Fermi, US)

P-P+ 2 - 2009 1032

2 fb-1/sy

LHC

(CERN, SW)

PP 14 2008 - 6 1033

120 fb-1

ILC (?) e+e- .5 - 1 2019 - 2 1034

200 fb-1

W. Morse May 15, 2007 4

Recent e+e- Colliders

Collider SLAC B

(USA)

KEK B

(Japan)

SLC

(USA)

LEP 1-2

(CERN)

Ecm

(TeV)

0.01 0.01 0.1

polarized

0.1-0.2

Years - 2008 - ? - 1998 - 2000

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PDG:

ZprecisioncomesfromSLC/LEP

W. Morse May 15, 2007 6

Exploring the TeraVolt Scale

• Protons are made up of quarks and gluons• Average quark or gluon carries 10% of the

proton’s energy• LHC: 1B uninteresting events/s, ie. need a

trigger• e+e- converts all the beam energy into the

collision energy• ILC: No uninteresting events/s, ie. no trigger!• Polarized electron positron beams• ILC dL/L 310-4 LHC dL/L 0.1

W. Morse May 15, 2007 7

JoAnne Hewett’s Slide

• Common feature of many models is a contact interaction type signature new gauge bosons,

large extra dimensions, compositeness, leptoquarks, string excitations, ….

-

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W. Morse May 15, 2007 9

International Linear Collider

• International from the start!• New paradigm for HEP• Global Design Effort of Asia, Europe, America• 2007 Reference Design Report – done!• 2009 Engineering Design Report• 2010 Tevatron/LHC Higgs physics results, ILC

site selection, International funding agreement ?• 2011-2018 Construction??• 2019 First Run ???

W. Morse May 15, 2007 10

W. Morse May 15, 2007 11

W. Morse May 15, 2007 12

W. Morse May 15, 2007 13

Physics - Higgs Mechanism

• Proposed by Peter Higgs almost fifty years ago• Spontaneous symmetry breaking to give particles mass• LEP direct search limit: MH>0.115TeV• Precision Electro-Weak Measurements at Tevatron

/LEP/SLC: MH < 0.2 TeV from virtual processes• Does nature give mass through Peter Higg’s

mechanism?• Only fundamental particle in the standard model with

spin zero!• Only particle in the standard model where the coupling

constant is proportional to mass.

W. Morse May 15, 2007 14

LHC2ILC Fermilab Apr 12-14• Reconstruct Higgs mass with collinear approximation

30 fb-1

H(ll) +2jets (VBF)

H(lh) +2jets (VBF)

W. Morse May 15, 2007 15

ILC with no trigger

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W. Morse May 15, 2007 17

ILC can vary beam energy

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Hints of SUSY?

• BNL measurement of the anomalous magnetic moment of the muon (2004):

• aexp = 0.0011659208 (6)• aSM = 0.0011659179 (6)• SUSY theorists relieved!• asusy tan/M2

• 0.13TeV < Msusy < 0.47TeV• J. Miller, E. De Rafael, B. Roberts, hep-ph 0703049

(2007) Review Article.

W. Morse May 15, 2007 20

D0 Z+Hbb Search

W. Morse May 15, 2007 21

Nominal ILC Parameters

Parameter ILC (0.5TeV) SLC (0.09TeV)

Luminosity 21034 cm-2s-1 21030 cm-2s-1

BX/s 15K .12K

y 5nm 500nm

x 500nm 1500nm

e/BX 21010 41010

W. Morse May 15, 2007 22

Feedback

• SLC found they needed feedback to optimize the luminosity with 1m beams – mainly beam position monitors (BPM).

• What detectors do we need to stabilize the beams at the 5nm level to achieve the design luminosity?

• 100V kicker.

W. Morse May 15, 2007 23

BNL Magnet Division Position Stability

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Achieving the ILC Luminosity Will Be a Challenge

• Bunch P- (t) {N, E, x, y, z, x, y, z, xy, x, y}• Bunch P+(t) {N, E, x, y, z, x, y, z, xy, x, y}• Beam motion >> 5nm!• Instantaneous Luminosity:

oy

ox

oo NNtL

)(

x

y

W. Morse May 15, 2007 25

Beam-strahlung Gammas

• F = e(E + cB)• E = 0, Bmax 1KT• P 3% Pe 0.4MW• N 1.5Ne 31010 /BX

mc

FrP

3

2 220

yzx

x

ycNeB

0

W. Morse May 15, 2007 26

Beam-strahlung Pairs

• Bethe-Heitler: e → e e+e-

BH 38 mb• <E> 1GeV• Landau-Lifshitz: ee → ee e+e-

LL 19 mb• <E> 0.15GeV• Breit-Wheeler: e+e-

BW 1 mb 104 e+e- /BX Maximum PT = 0.1 GeV/c

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Beam-strahlung Pairs

W. Morse May 15, 2007 28

Bethe-Heitler Pairs

e → e e+e-

oy

ox

oe

oBH

ee

NNN

oy

ox

oeBHee N

N

N

oy

ox

oeee N

E

E

For left and right detectors separately: N+/xy and N-/xy.

W. Morse May 15, 2007 29

Vertical offset

0

50

100

150

200

-200 -100 0 100 200

offset/2 (nm)

ener

gy

in g

amm

as (

MT

eV)

0

5

10

gammas

pairs

E BeamCal (TeV)

W. Morse May 15, 2007 30

Vertical Offset

0

5

10

15

20

-200 -150 -100 -50 0 50 100 150 200

offset/2 (nm)

Lu

min

osi

ty (

10^

33 c

m^

-2/s

)

0

0.05

0.1

Lum

R

R (10-6)

W. Morse May 15, 2007 31

Bunch Height

0

40

80

120

160

200

240

3 5 7 9 11

Bunch height (nm)

Energ

y in g

amma

s (MT

eV)

0

4

8

12

16

gammas

pairs

0

2

46

8

10

1214

16

18

3 5 7 9 11

Bunch height (nm)

Lum

inos

ity (1

0^33

cm^-

2/s)

0

0.02

0.04

0.06

0.08

Lum

R

W. Morse May 15, 2007 32

Bunch Length

0

50

100

150

200

250

300

350

150 200 250 300 350 400

Bunch Length (um)

gam

ma e

nerg

y (MT

eV)

0

5

10

15

20

25

gammas

pairs

0

2

46

8

10

1214

16

18

150 200 250 300 350 400

Bunch length (um)

Lum

(10^

33 cm

^-2/s

)0

0.02

0.04

0.06

0.08

Lum

R

W. Morse May 15, 2007 33

Forward Calorimeters

• LumiCal – forward Bhabhas for precision integrated luminosity measurement

• BeamCal – beam-strahlung pairs for instantaneous luminosity

• GamCal - beam-strahlung gammas for instantaneous luminosity

W. Morse May 15, 2007 34

International FCAL R&D Coll.

• W. Lohmann (DESY Zeuthen) spokesman• W. Morse (BNL) beam diagnostics

(BeamCal/GamCal) coordinator• B. Pawlik (Cracow) simulations

coordinator• W. Lange (DESY) sensors coordinator• TBD electronics coordinator• W. Wierba (Cracow) LumiCal laser

alignment coordinator

W. Morse May 15, 2007 35

U.S. Forward (SiD)

• W. Morse (BNL): Coordinator• G. Haller, A. Abusleme, M. Breidenbach, D.

Freytag (SLAC): BeamCal readout design• Z. Li (BNL): BeamCal radiation damage issues• B. Parker (BNL): machine interface issues• M. Zeller, G. Atoian, V. Issakov, A. Poblaguev

(Yale): GamCal design• Y. Nosochkov (SLAC): Extraction line issues• U. Nauenberg (Colorado): SUSY studies

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BeamCal

• .003 < < .02 rad3.5m from IR

• Measure the 104 beam-strahlung e+e- pairs/BX for beam diagnostics

• 2-10MGy/year

• Beam diagnostics and hermeticity for SUSY searches.

W. Morse May 15, 2007 37Collaboration

High precision design DESY-PRC2006

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GamCal Detector

180m from IR 10-4 X0 to convert beam-strahlung gammas into

e+e- pairs• Converter could be gas jet or a thin solid

converter• Magnet to separate pairs from beam electrons! 3 1010 beamstrahlung gammas (2 GeV) 2 1010 beam electrons (0.2 TeV)• Evaluate the effect of beam electrons going

through conveter

W. Morse May 15, 2007 39

Beam-strahlung ZeeZ

0

5

10

15

20

0 1 2 3 4 5 6 7 8 9 10

E (GeV)

E d

N/d

E

W. Morse May 15, 2007 40

GamCal Backgrounds

Gammas

1.E+04

1.E+05

1.E+06

1.E+07

1.E+08

1.E+09

-2 -1 0 1 2

log(E)

dN/d

log(

E)

Beamst

Brem

1

10

100

1000

-2 -1 0 1 2

log(E)

dN/d

log(

E) Delta Rays

Beamst e

W. Morse May 15, 2007 41

ZeeZ vs. eZ eZee

• Electron carries virtual gammas

• Landau Lifshitz conversion of virtual gammas

2

11.1ln

12

minb

c

d

dN

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Ratio of ZeeZ vs. eZ eZee

0

7

14

21

-1 0 1

log_10 (E)

Rati

o

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Production Compared to ee

p eep 10 mbp N 0.5 mb in Δ resonance

regionp N 0.1 mb E > 4GeV

• ep e N 10-3 mb

• Thus ep e N is negligible

W. Morse May 15, 2007 44

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Yale IBS Design

W. Morse May 15, 2007 46

Feed-back with Luminosity Detectors

P.N. Burrows GDE/MDI Vancouver 19/7/06

Intra-train y + y’ IP feedback simulations

0 100 200 300 400 500 6000

1

2

3x 10

34

Bunch #

Lu

min

os

ity

/ c

m-2s

-1

y position FB:

restore collisions

within 100 bunches1 seed:

post-BBA

+ GM

+ wakes

y position scan:

optimise signal

in pair monitor

y angle scan

OPTIMAL

LUMINOSITY

W. Morse May 15, 2007 47

Conclusions

• We have designs for beam-strahlung pair and gamma detectors.

• Studies, simulations continuing.• Ratio of the beamstrahlung pairs

(BeamCal) to gammas (GamCal) is largely proportional to the instantaneous luminosity.

• Use feedback to bring 5nm beams into collision at maximum luminosity

W. Morse May 15, 2007 48

Extra Slides

W. Morse May 15, 2007 49

ILC Timeline

• Reference Design 2007

• Engineering Design 2009

• Site selection, LHC Physics results, International Funding Agreement 2010

• Construction Starts 2011

• Construction Ends 2018

• First Run 2019

W. Morse May 15, 2007 50

1 2

0

21

y

E

0

21

y

B

+ -

0

221

212

01

2

eyey

F

y

z

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Perfect Collisions

zx

NE

2

2

zyx

ee

NE

3

3

W. Morse May 15, 2007 52

0

100

200

300

400

500

600

400 500 600 700 800 900

Bunch width (nm)

En

erg

y in

gam

mas

(M

TeV

)O

0

10

20

30

40

50

60

gammas

pairs

W. Morse May 15, 2007 53

0

5

10

15

20

25

30

400 500 600 700 800 900

Bunch width (nm)

Lu

min

osi

ty (

10^

33 c

m^

-2/s

)

0

0.02

0.04

0.06

0.08

0.1

0.12

Lum

R