# Presentation: 885195

## Muon (g-2) to 0.25 ppm

**B. Lee Roberts**
**on behalf of the**
**New Muon (g-2) Collaboration: E969  **

## BNL E969 Collaboration

-     **R.M. Carey, I. Logashenko, K.R. Lynch, J.P. Miller, B.L. Roberts **
**Boston University**** **
**G. Bunce, W. Meng, W. Morse, P. Pile, Y.K. Semertzidis **
**Brookhaven National Laboratory****  **
**D. Grigoriev, B.I. Khazin, S.I. Redin, Y. M. Shatunov, E. Solodov  **
**Budker Institute of Nuclear Physics**
**F.E. Gray, B. Lauss, E.P. Sichtermann  **
**UC Berkeley and LBL**
** ****Y. Orlov – ****Cornell University**
** ****J. Crnkovic****, P. Debevec, D.W. Hertzog, P. Kammel, S. Knaack, R. McNabb**
** ****University of Illinois at Urbana-Champaign**
**   ****K.L. Giovanetti – ****James Madison University**
** ****K.P. Jungmann, C.J.G. Onderwater – ****KVI Groningen****  **
**T.P. Gorringe, W. Korsch ****U. Kentucky**** **
**P. Cushman – ****University of**** ****Minnesota**
**M. Aoki, Y. Arimoto, Y. Kuno, A. Sato, K. Yamada **
** ****Osaka University**
** ****S. Dhawan, F.J.M. Farley – ****Yale University**

**This group contains the core of E821, and we will build on our strength and experience there. **

## When we started in 1983, theory and experiment were known to about 10 ppm.

**Theory uncertainty     was ~ 9 ppm**
**Exp.  uncertainty was 7.3 ppm**

## E821 achieved 0.54 ppm and the e+e- based theory is also at the 0.6 ppm level. Both can be improved.

***All E821 results were obtained with a “***_***blind***_***” analysis.***

## This large number of citations demonstrate widespread interest in the community.

**This large number of citations demonstrate widespread interest in the community.**

**Precision measurements provide an alternate path to the frontier of particle physics. **_**Whatever LHC finds, muon (g-2) will provide independent constraints on the parameter space for new physics.**_

**99    00    01   02    03   04    05   06    **

**350**
**300**
**250**
**200**
**150**
**100**
**  ****50**
**    ****0**

**Citations to E821 Physics Results**

**PRL 82 (1999)**

**PRD 62 (2000)**

**PRL 89 (2002)**

**PRL 92 (2004)**

****** ****= 1127**

**PRL 86 (2001)**

## We measure the difference frequency between the spin and momentum precession

- 0

**With an electric quadrupole field for vertical focusing**

## Experimental Technique

**Inflector**

- Storage
- ring

- Injection orbit

**Pions**

**Target**

**Protons**

**(from AGS)**

**p=3.1GeV/c**

**Experimental Technique**

-  **Muon polarization**
** ****Muon storage ring**
** ****injection & kicking**
** ****focus by  Electric Quadrupoles**
** ****24 electron calorimeters**

**(1.45T)**

## We count high-energy electrons as a function of time.

**We count high-energy electrons as a function of time.**

## E821 used a forward decay beam, with p 1.7% above pmagic to provide a separation at K3/K4

**Near side**

**Far side**

**E821 used a forward decay beam, with p******** 1.7% above p****magic ****to provide a separation at ****K3/K4**

**Pions @ 3.115 GeV/c**

**Decay muons @ 3.094 GeV/c**

**Our models show that by quadrupling the quads and going further above p****magic **** the flash is decreased and the muon flux will grow by  approximately 2-3**

## Space limitations prevent matching the inflector exit to the storage aperture

## The E821 inflector magnet had closed ends which scattered away half the beam.

**Length  = 1.7 m;   Central field = 1.45T**

**Open end prototype, built and tested**
**→****X2 Increase in Beam**

## E969 needs 5 times the muon flux that E821 stored.  

**Open inflector ****	****	****   ****	****	****   ****	****x 2**
**Quadruple the quadrupoles  ****	****  ****	**** ****	****x 2 – 3**
**	****Beam increase design factor****	****	**** ****	****x 4 – 6**
**  ****	****At 3% above p****magic**** the reduced injection flash will permit us to begin fitting the data at earlier times (closer to the injection time) than in E821.**

## E969 New Baseline – 0.25 ppm total error

**Systematic error goals:**
**for ********a****:    0.1 ppm**
**for ********p****:    0.1 ppm**
**Statistical error goal:**
**for ********a****:    0.2 ppm**
**Total Error Goal:**
**a********:   0.25 ppm**
**Forward beam with 4x quadrupoles**
**New detectors / electronics**
**Upgraded NMR system**

## The error budget for E969 represents a continuation of improvements already made during E821

**Field improvements:**** ****better trolley calibrations,  better tracking of the field with time, improvements in the hardware**
**Precession improvements**** ****will involve new scraping scheme, lower thresholds, more complete digitization periods, better energy calibration**

| Systematic uncertainty (ppm) | 1998 | 1999 | 2000 | 2001 | E969
Goal |
| --- | --- | --- | --- | --- | --- |
| Magnetic field – p  | 0.5 | 0.4 | 0.24 | 0.17 | 0.1 |
| Anomalous precession – a   | 0.8 | 0.3 | 0.31 | 0.21 | 0.1 |

| Statistical uncertainty (ppm) | 4.9 | 1.3 | 0.62 | 0.66 | 0.2 |
| --- | --- | --- | --- | --- | --- |
| Total Uncertainty (ppm) | 5.0 | 1.3 | 0.73 | 0.72 | 0.25 |

## The magnetic field is measured and controlled using pulsed NMR and the free-induction decay.

**The magnetic field is measured and controlled using pulsed NMR and the free-induction decay.**

**Calibration to a spherical water sample that ties the field to the Larmor frequency of the free proton***** ************p***
**Thus we measure ***********a***** and ***********p***

## The ± 1 ppm uniformity in the average field is obtained with special shimming tools.

- We can shim the
**dipole,**** **
**quadrupole**
**sextupole**** **
- independently
**E969 will require additional shimming, monitoring and calibration**

- 0.5 ppm contours

## Field systematic uncertainties, ordered by importance

| Source | E821
(ppm) | E969
(ppm) | Comment |
| --- | --- | --- | --- |
| Calibration of trolley probe | 0.09 | 0.06 | Improved shimming in the calibration  region; improved registration of trolley location in ring |
| Interpolation with fixed probes | 0.07 | 0.06 | Repairs and retuning of a number of probes to improve the sampling of the ring field |
| Absolute calibration | 0.05 | 0.05 | Could improve using  3He |
| Trolley measurements of B0 | 0.05 | 0.02 | More frequent trolley runs; mechanical maintenance of trolley drive and garage; extensive measurements of trolley NMR probe active volumes |
| Muon distribution | 0.03 | 0.02 | Simulations of storage ring; improved shimming |
| “Other”
	eddy currents
	higher multipoles
	trolley temp and PS response
	 | 0.10 | 0.05 | 
in situ measurement of eddy currents
Improved shimming
Modifications to trolley and PS |
| Total | 0.17 | 0.11 |  |

## New segmented detectors of tungsten / scintillating- fiber ribbons to deal with pile-up

**System fits in available space**
**We know how to cost and build it. (prototype under construction)**
**Calibration method reasonable**
**Bases will be gated.**
**New custom electronics and DAQ**

## Precession frequency systematic uncertainties, ordered by importance

| Source | E821
(ppm) | E969
(ppm) | Comments |
| --- | --- | --- | --- |
| Gain stability | 0.12 | 0.03 | Full WFD samples recorded; stability of laser calibration with local reference detectors; single-phase WFDs |
| Lost muons | 0.09 | 0.04 | New scraping scheme; improved kick |
| Pileup | 0.08 | 0.07
 | Recording all samples, no threshold, will eliminate ambiguity from low-energy pulses |
| CBO: coherent betatron oscillations | 0.07 | 0.04 | Improved kick; new scraping |
| E and pitch correction | 0.05 | 0.05 | Should be improved with better storage ring simulation, but we keep it as is for now |
| Timing shifts | 0.02 | 0.01 | Laser calibration; precision determined by amount of data collected |
| AGS background | 0.01 | 0.01 | Sweeper magnet maintained |
| Fit procedure and bin width | 0.06 | 0.01 | Limited by number of simulated trials performed |
| Vertical waist | 0.03 | 0.01 | CBO related; see above |
| Other small effects | < 0.03 | < 0.02 | These either scale with the data set size or from the simulations demonstrating “no effect” |
| Total | 0.21 | 0.11 |  |

## Summary:  E821 and E969 Costs

| Baselining costs | 0.4 |
| --- | --- |
| AGS/Booster Rehab including ES&H | 11.7 |
| Construction (44% contingency) | 12.2 |
| Universities (27% contingency) | 2.4 |
| Operations (includes FTEs to support cryo and external beam operations) | 13.6 |
| Total Costs | 40.2 |

**Summary:  E821 and E969 Costs**

**E821 costs (M$)       (as spent $)**
**Capital          25.0 1989-1998**
**Operations   54.0 1998-2001**
**Total E821   79.0**

**E969 Costs (2006 M$)**

## Funds needed to baseline the costs (not included in construction cost estimate)

**Funds needed to baseline the costs ****(not included in construction cost estimate)**

**1.0 g-2 Ring/Building maintenance**
**1 man month to engineer an air conditioning system for bldg 919**
**1.1 V/V1 Beam Lines**
**1 man-months engineering**
**1 man-months physicist**
**1.2 Inflector **
**A quote from the Furukawa Company for superconductor**
**1.3 E Quads**
**Nothing new, defendable**
**1.8 Kicker**
**Nothing new, defendable**
**1.11 Cryogenics (****to determine scope)**
**2 man-months engineering**
**1 man-month tech**
**1.12 Vacuum System**
**1 man-month engineering**
**1.14 Booster/AGS**
**0.5 man month engineering**
**0.5 man month physicist**

**ES&H – review operation within present guidelines**
**1 man-month physicist**
**1 man month engineer**
**Preparation of Cost Books, Resource Loaded Schedules, CD0-1 documents etc**
**4 man-months engineering**
**4 man--months physicist**
**Summary**
**11 man-month engineering**
**  ****7 man-month physicist**
**  ****1 man-month tech**
**Required Budget ~ $360K**
**Calendar Time Required           ~ 6-8 months**

## Cost Summary: E969 Construction

**Cost Summary: E969 Construction**

**Experiment Construction, Direct Costs****	**_**M$**_**	****       **_** Contingency**__** **_
**G-2 Ring and building****	****	****	****$   0.56****	****	****21%**
**V/V1 Beam Line modifications****	****	****$   2.59****	****	****18%**
**Inflector (open ends)****	****	****	****$   0.64****	****	****19%**
**E-Quad rebuild****	****	****	****$   0.13****	****	****15%**
**Additional muon Kicker****	****	****	****$   0.41****	****	****15%**
**Cryogenic plant rehab****	****	****	****$   0.74****	****	****233%**
**Ring Vacuum System ****	****	****	****$   0.16****	****	****29%**
**Equipment Testing****	****	****	****$   0.69****	****	****20%**
**Project Office****	****	****	****$   0.37****	****	****20%**
**Sub-Total, direct costs****	****	****	****$   6.3**
**Indirects (reduced)****	****	****	****$   2.2**
**Contingency (44%)****	****	****	****$   3.7**
**Sub-Total, with indirects****	****	****	****$ 12.2**
**University (Detectors/DAQ)****	****	****$   2.4**
**Total****	****	****	****	****$ 14.6**
**	****	**

_***FY 2006 $’s***_

## Cost  Summary: AGS/Booster Restoration to High Intensity

**Cost  Summary:**** AGS/Booster Restoration to High Intensity**

**AGS/Booster, Direct Costs****	****	**_**M$**_**	****        **_**Contingency**__** **_
**Electrical Modifications****	****	****$   2.11****	****	****22%**
**Mechanical Modifications****	****	****$   1.25****	****	****20%**
**RF System Modifications****	****	****$   0.67****	****	****22%**
**Instrumentation****	****	****	****$   0.34****	****	****20%**
**Project Support****	****	****	****$   0.33****	****	****34%**
**Controls****	**** ****	****	****	****$   0.16****	****	****24%**
**ES&H (CAPS)****	****	****	****$   2.63****	****	****28%**
**Sub-Total, direct costs****	****	****$   7.5**
**Indirects (reduced)****	****	****	****$   1.9**
**Contingency (24%)****	****	****	****$   2.3**
**Total****	****	****	****	****$  11.7**
**	****	****	**

_***FY 2006 $’s***_

## E969 Operations Cost Summary

**E969 Operations Cost Summary**

_**Year**__**	**_**    **_**Wks w/RHIC**_**	****  **_**Wks Alone**_**    **_**Physics Wks**_**  **_**Cost (M$)**_** **
**	****1****st****         12****	****	****      0****	****	****        3****	****	****    $   5.8**
**	****2****nd****	****     **_**20**__**	**__**	**__**      0**__**	**__**	**__**       15  **__**	**__**                 $   7.8**_
**Total          34                      0                           18                   $ 13.6**
**If warranted to push beyond 0.25 ppm, an additional 10-15 week run with RHIC adds ~$6-7M**
**	****	****	**

_***FY 2006 $’s***_

## Funding Profile by Year

## Summary

**Historically (g-2) has placed a major hurdle in the path of new theories beyond the standard model.**
**See the letters from Altarelli, Davier, Ellis, Jackiw, Jaffe, Kane, Wilczek, Winstein**
**The (g-2) result must fit with other evidence into a consistent picture of new physics, ****e.g.**

## The (g-2) discrepancy is consistent with other constraints on the SUSY LSP being the dark matter candidate.

**scalar mass**

**gaugino mass**

**CMSSM calculation Following Ellis, Olive, Santoso, Spanos, from K. Olive**

## Future Comparison:          E969 = 0.25 ppm;   E969 = now

## Future Comparison:           E969 = 0.25 ppm;   E969 

- Historically (g-2) has played an important role in restricting models of new physics.

## Summary, ctd.

**Historically (g-2) has placed a major hurdle in the path of new theories beyond the standard model.**
**This hurdle is ****unique and complementary**** to other information.**
**Theory ****can and will**** support the proposed experimental improvement. **
**See the letters from Davier, De Rafael**
**E969 provides an important opportunity to capitalize on the substantial  investment in E821.**

## Closing Points

**Muon (g-2) will be important to particle physics even beyond the LHC era**
**A large community continues to improve the knowledge of the strong-interaction contribution.**
**E969 will be a wonderful and unique training ground for young scientists.**
**E969 presents a unique opportunity for U.S. particle physics.**

## Extra Projections

## Also attractive for E969 is a “backward” decay beam, which we continue to model.

**Also attractive for E969 is a “backward” decay beam, which we continue to model.**

**Pions @ 5.32 GeV/c**

**No hadron-induced prompt flash**

**By quadrupling the quads, the muon flux will grow by  ~1.6, but the hadronic flash will largely be eliminated.**

**new front-end**

- increase of proton beam

**Decay muons @ 3.094 GeV/c**

## g-2 Experiment Operations (0.5 ppm)

_***FY 2006 $’s***_

## g-2 Experiment Operations (0.25 ppm)

_***FY 2006 $’s***_

## g-2 Experiment Operations (0.20 ppm)

_***FY 2006 $’s***_

## T. Kirk’s 4 Dec 04 letter to DOE

- Construction Cost - $11M+
- Beam line g-2 ring upgrades etc  - $11M
- Cost sharing with RSVP of AGS/Booster rehab – discussed but  not specified
- Operations Cost - $9-10M+
- 25 week single year cost - $9-10M
- 3 week engineering run costs – discussed but not specified

## Variance with T. Kirk’s 4 Dec 04 letter to DOE

**Construction Cost: $26M today ($9M + $2M Inflector, Kirks letter)**
**Scope changes: +$4.1M**
**Beam Line – fwd decay (was back decay w/1X FODO) with 4X FODO (-$2M)**
**Contingency for new cryo plant + $2M**
**New Kicker, EQuad Rebuild, Bldg 919 AC + $1M**
**Equipment testing (some with beam) + $1M**
**Project Office + $0.7M**
**Universities (detectors/DAQ) + $1.4M**
**Revised cost estimates, inflation: (-$1M inflector, + $1M other)**
**Cost of AGS/Booster rehab: +$11.7M (no cost sharing)**
**Operations Cost: $13M, 2 year base plan**
**Engineering/data run, one 12 week year - $6M (3 weeks in Kirk’s letter – no costs specified)**
**Data Runs, one 20 week year – $8M  (Kirk’s letter $9-10M for 25 weeks)**
**Variance ~ consistent with Kirk’s letter**

## Milestones/Timeline  (by FY)

**CD0 ****  Beamline design – backward/forward decision; detector prototype; simulations of injection, scraping, CBO damping; decide on scope of cryo work; begin tube/base development**
**+9 Months  ****CD1****; Begin electronics engineering**
**CD2**** - Engineering on beamline, Cryo**
**CD3**** - Start to order long leadtime items e.g. Inflector, rad-hard front-end magnets, etc.;  Refurbish storage ring; develop on-line; develop NMR tools for 0.1 ppm.**
**Construction**** **
**Shim magnet, improve on absolute calibration**
**CD4**** - Finish construction, few weeks of  low intensity beam**
**Commission experiment, engineering and short physics run**
**Major data collection run**

**-1**
**0**
**+1**
**+2**
**+3**
**+4**
**+5**