# Presentation: 658817

## Colliding 5nm Beams at the International Linear Collider

- William Morse
- Brookhaven National Lab

- SiD SLAC October 28 2006 W.M. Morse

## 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

- SiD SLAC October 28 2006 W.M. Morse

## 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 |

- SiD SLAC October 28 2006 W.M. Morse

## 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 |

- SiD SLAC October 28 2006 W.M. Morse

## PDG:ZprecisioncomesfromSLC/LEP

- SiD SLAC October 28 2006 W.M. Morse

## 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  310-4    LHC dL/L  0.1

- SiD SLAC October 28 2006 W.M. Morse

## 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, ....

**-**

- SiD SLAC October 28 2006 W.M. Morse

- SiD SLAC October 28 2006 W.M. Morse

## 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 ???

- SiD SLAC October 28 2006 W.M. Morse

- SiD SLAC October 28 2006 W.M. Morse

- SiD SLAC October 28 2006 W.M. Morse

- SiD SLAC October 28 2006 W.M. Morse

## 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.

- SiD SLAC October 28 2006 W.M. Morse

## 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+Hbb Search 

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## Nominal ILC Parameters

| Parameter | ILC (0.5TeV) | SLC (0.09TeV) |
| --- | --- | --- |
| Luminosity | 21034 cm-2s-1 | 21030 cm-2s-1 |
| BX/s | 15K | .12K |
| y | 5nm | 500nm |
| x | 500nm | 1500nm |
| e/BX | 21010 | 41010 |

- SiD SLAC October 28 2006 W.M. Morse

## Feedback

- SLC found they needed feedback to optimize the luminosity with 1m 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:

- x

- y

- SiD SLAC October 28 2006 W.M. Morse

## Beam-strahlung Gammas

- F = e(E + cB)
- E = 0, Bmax  1KT
- P  3% Pe   0.4MW
- N  1.5Ne   31010 /BX

- SiD SLAC October 28 2006 W.M. Morse

## 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

- SiD SLAC October 28 2006 W.M. Morse

## Beam-strahlung Pairs

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## Bethe-Heitler Pairs

- e → e e+e-

- For left and right detectors separately: N+/xy and N-/xy.

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## Vertical offset

**E BeamCal (TeV)**

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## Vertical Offset

**R (10****-6****)**

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## Bunch Height

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## Bunch Length

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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

- SiD SLAC October 28 2006 W.M. Morse

## 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

- SiD SLAC October 28 2006 W.M. Morse

## 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

- SiD SLAC October 28 2006 W.M. Morse

## BeamCal

- .003 <  < .02 rad
- 3.5m from IR
- Measure the 104 beam-strahlung e+e- pairs/BX for beam diagnostics
- 2-10MGy/year
- Beam diagnostics and hermeticity for SUSY searches.

- SiD SLAC October 28 2006 W.M. Morse

***DESY-PRC******2006***

- SiD SLAC October 28 2006 W.M. Morse

## 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 ZeeZ

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## GamCal Backgrounds

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## ZeeZ vs. eZ eZee 

- Electron carries virtual gammas
- Landau Lifshitz conversion of virtual gammas

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## Ratio of ZeeZ vs. eZ eZee

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##  Production Compared to ee

- p  eep    10 mb
- p   N    0.5 mb in Δ resonance region
- p   N    0.1 mb    E > 4GeV
- ep  e  N      10-3 mb
- Thus ep  e  N is negligible

- SiD SLAC October 28 2006 W.M. Morse

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## Yale IBS Design

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## Feed-back with Luminosity Detectors

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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

- SiD SLAC October 28 2006 W.M. Morse

## 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

- SiD SLAC October 28 2006 W.M. Morse

## 1  2

- +

- -

- y

- z

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## Perfect Collisions

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