W. Morse May 15, 2007 1

Colliding 5nm Beams at the International Linear Collider

William MorseBrookhaven 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/syLHC

(CERN, SW)PP 14 2008 - 6 1033

120 fb-1

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

200 fb-1

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Recent e+e- Colliders

Collider SLAC B(USA)

KEK B(Japan)

SLC(USA)

LEP 1-2(CERN)

Ecm

(TeV)

0.01 0.01 0.1polarized

0.1-0.2

Years - 2008 - ? - 1998 - 2000

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PDG:

ZprecisioncomesfromSLC/LEP

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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

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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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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 ???

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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.

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

30 fb-1

H(ll) +2jets (VBF)

H(lh) +2jets (VBF)

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ILC with no trigger

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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.

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D0 Z+Hbb Search

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Nominal ILC ParametersParameter 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

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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.

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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

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Beam-strahlung Gammas

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

mcFrP

32 220

yzx

xycNeB

0

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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

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Bethe-Heitler Pairs

e → e e+e-

oy

ox

oe

oBH

ee

NNN

oy

ox

oeBHee N

NN

oy

ox

oeee N

EE

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

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Vertical offset

0

50

100

150

200

-200 -100 0 100 200

offset/2 (nm)

ener

gy in

gam

mas

(MTe

V)

0

5

10

gammas

pairs

E BeamCal (TeV)

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Vertical Offset

0

5

10

15

20

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

offset/2 (nm)

Lum

inos

ity (1

0^33

cm

^-2/

s)

0

0.05

0.1

Lum

R

R (10-6)

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Bunch Height

0

40

80

120

160

200

240

3 5 7 9 11

Bunch height (nm)

Energy

in gam

mas

(MTe

V)

0

4

8

12

16

gammas

pairs

02468

1012141618

3 5 7 9 11

Bunch height (nm)

Lum

inos

ity (1

0̂33

cm̂

-2/s)

0

0.02

0.04

0.06

0.08

Lum

R

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Bunch Length

0

50

100

150

200

250

300

350

150 200 250 300 350 400

Bunch Length (um)

gam

ma en

ergy

(MTe

V)

0

5

10

15

20

25

gammas

pairs

02468

1012141618

150 200 250 300 350 400

Bunch length (um)

Lum

(10̂

33 cm̂

-2/s)

0

0.02

0.04

0.06

0.08

Lum

R

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Forward Calorimeters

• LumiCal – forward Bhabhas for precision integrated luminosity measurement

• BeamCal – beam-strahlung pairs for instantaneous luminosity

• GamCal - beam-strahlung gammas for instantaneous luminosity

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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

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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 37CollaborationHigh 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

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Beam-strahlung ZeeZ

0

5

10

15

20

0 1 2 3 4 5 6 7 8 9 10

E (GeV)

E dN

/dE

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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)

BeamstBrem

1

10

100

1000

-2 -1 0 1 2log(E)

dN/d

log(

E) Delta RaysBeamst e

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ZeeZ vs. eZ eZee

• Electron carries virtual gammas• Landau Lifshitz conversion of virtual

gammas

211.1ln12

minbc

ddN

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Ratio of ZeeZ vs. eZ eZee

0

7

14

21

-1 0 1

log_10 (E)

Ratio

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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

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Yale IBS Design

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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 #

Lum

inos

ity /

cm-2s-1

y position FB:restore collisionswithin 100 bunches

1 seed:

post-BBA

+ GM

+ wakes

y position scan:optimise signal in pair monitor

y angle scan

OPTIMALLUMINOSITY

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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

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Extra Slides

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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

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1 2

0

21

yE

0

21

yB

+ -

0

221

212

01

2

eyeyF

y

z

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Perfect Collisions

zx

NE 2

2

zyx

eeNE

3

3

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0

100

200

300

400

500

600

400 500 600 700 800 900

Bunch width (nm)

Ener

gy in

gam

mas

(MTe

V)O

0

10

20

30

40

50

60

gammas

pairs

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0

5

10

15

20

25

30

400 500 600 700 800 900

Bunch width (nm)

Lum

inos

ity (1

0^33

cm

^-2/

s)

0

0.02

0.04

0.06

0.08

0.1

0.12

Lum

R