RSVP: The Future of High Energy Physics at the AGS

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RSVP The Future of High Energy Physics at the AGS

• Michael Hebert
• UC Irvine
• RHIC AGS Users Meeting
• BNL, May 15 16, 2003

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Rare Symmetry Violating Processes

• RSVP is an approved NSF Major Research Equipment
  and Facilities Construction project for two new
  AGS experiments that could profoundly change our
  understanding of physics
• MECO is a search for physics beyond the Standard
  Model via
  at the level of 2 10-17, or four orders
  of magnitude more sensitivity than previous
  similar experiments
• KOPIO seeks to directly measure h, the complex
  phase in the CKM matrix that leads to CP
  violation in the Standard Model via

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MECO Collaboration

• Institute for Nuclear Research, Moscow
• V. M. Lobashev, V. Matushka,
• New York University
• R. M. Djilkibaev, A. Mincer,
  P. Nemethy, J. Sculli, A.N. Toropin
• Osaka University
• M. Aoki, Y. Kuno, A. Sato
• University of Pennsylvania
• W. Wales
• Syracuse University
• R. Holmes, P. Souder
• College of William and Mary
• M. Eckhause, J. Kane, R. Welsh

• Boston University
• J. Miller, B. L. Roberts, O. Rind
• Brookhaven National Laboratory
• K. Brown, M. Brennan, G. Greene,
• L. Jia, W. Marciano, W. Morse,
  Y. Semertzidis, P. Yamin
• University of California, Irvine
• M. Hebert, T. J. Liu, W. Molzon, J.
  Popp, V. Tumakov
• University of Houston
• E. V. Hungerford, K. A. Lan, L.
  S. Pinsky, J. Wilson
• University of Massachusetts, Amherst
• K. Kumar

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Studying PeV Scale Effects at the AGS

• Discovery of or a similar
  charged lepton flavor violating (LFV) process
  would be unambiguous evidence for new physics
• Such processes should occur via n mixing, but the
  rate is infinitesimal.
• Charged LFV occurs in nearly all scenarios for
  physics beyond the SM, in many cases at levels
  that MECO or PSI MEG will detect.
• Effective mass reach of a sensitive search is
  
  enormous, well beyond that accessible with
  
  direct searches, e.g. for leptoquarks in
  MECO

The intensity and time structure of the AGS make
it the machine to provide the immense numbers of
protons needed to reach this level
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SUSY Predictions for Charged LFV

• From Hall and Barbieri
• Large t quark Yukawa couplings imply observable
  levels of LFV in supersymmetric grand unified
  models
• Extent of LFV in grand unified SUSY is related to
  quark mixing
• Original ideas extended by Hisano, et al.

Current MEGA bound
Current SINDRUM2 bound
B(? ? e g)
R?e
PSI-MEG single event sensitivity
MECO single event sensitivity
100 200
300 100
200 300
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Muon to Electron Conversion

• Low energy muons are stopped in Al foils, forming
  muonic atoms
• Three possible fates for the muon
• Nuclear capture
• Three body decay in orbit
• Coherent LFV decay
• Signal is a single mono-energetic electron
• Rate is normalized to the kinematically similar
  weak capture process

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MECO Backgrounds

• The dominant background is muon decay in orbit
• Steeply falling spectrum near endpoint, e.g.
• This sets the required energy resolution
• Nbkgd ? 0.25 for Rme 1 ? 10-16 ? DEe ? 900 keV
  (FWHM)
• Prompt backgrounds are suppressed
  by
  pulsing the primary proton beam
• Beam pulse duration ltlt m lifetime
• Pulse separation m lifetime in Al
• Extinction between pulses lt 10-9
• All other backgrounds eliminated by a combination
  of energy resolution, shielding, and active
  cosmic ray veto

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Features of the MECO Experiment

• 1000fold increase in m beam intensity over
  existing facilities
• High Z target for improved pion production
• Axially-graded 5 T solenoidal field to maximize
  pion capture

Superconducting Solenoids
Muon Beam
1 T
1 T
Calorimeter
2 T
Straw Tracker
Stopping Target Foils
Proton Beam
2.5 T

• Curved transport selects low momentum m-
• Muon stopping target in a 2 T axially-graded
  field to improve
  conversion e- acceptance
• High rate capability electron detectors in a
  constant 1 T field

5 T
Pion Production Target
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Expected MECO Performance
Side View of Spectrometer
Axial View
Background with Detector Response
Simulated signal event
If m ? e conversion occurs at a rate of Rme 1 ?
10-16 MECO should observe 5 events with 0.25
events background
900 keV FWMH
Full GEANT Simulation Signal
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MECO RD Efforts

• Tracker Studies
• Chamber prototypes at Houston Osaka
• Electronics design at Houston
• Detector simulation at NYU and UCI
• Straw testing at UCI

• Muon Beamline Development
• Vacuum window conceptual design at BNL
• Optimization studies at UCI
• Muon stop monitor tests planned by William Mary
• Detector support and installation design at BNL
  NYU

Production Target Prototyping at UCI
Calorimeter Prototyping at NYU
Cosmic Ray Veto System (Not Shown) Prototyping
at William Mary
Magnet Design at MIT UCI
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The MECO Magnets
The superconducting solenoids define the critical
path for MECO

• Very detailed CDR completed (300 pages)
• Complete 3D drawing package
• Technical Specification and SOW for commercial
  procurement being prepared
• Industrial manufacturability studies completed
• Interface engineering ongoing as funds allow

• 5 T maximum field
• 150 MJ stored energy
• Uses surplus SSC cable
• Within industry capabilities

• Draft RFP to be released at the end of the summer
• Preliminary safety input from 6/3 meeting here

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Snapshots of Other MECO RD

• Houston has constructed a 3 m Tracker prototype
  vane to study mechanical aspects of the design
• Prototype front-end electronics evaluated on
  smaller prototype chambers, signals in pads
  resistive straws meet expectations
• Osaka has developed seamless straws and tested
  their behavior in small prototype chambers at
  KEK, initial results are very encouraging
  although 3m length is a challenge
• Calorimeter crystal evaluations underway at NYU.
  Cooled PbWO4 with large area APD appears viable
• AGS engineers have completed a conceptual design
  for the anti-proton stopping window magnet
  interface

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The KOPIO Collaboration
Brookhaven National Laboratory I-H. Chiang, J.W.
Glenn, D. Jaffe, D. Lazarus, K. Li, L.
Littenberg,
G. Redlinger, C. Scarlett, M. Sivertz, A.
Stevens, R. Strand University of Cinncinnati K.
Kinoshita IHEP, Protvino G.Britvich,
S.Chernichenko, R.Rogalev, V.Semenov, I.Shein,
A.Soldatov, N.Tyurin, V.Vassil'chenko,
A.Yanovich INR, Moscow A. Ivashkin, D.Ishuk, M.
Khabibullin, A. Khotjanzev, Y. Kudenko, A.
Levchenko, O. Mineev, N. Yershov and A.Vasiljev.
INFN-University of Perugia G. Anzivino, P.
Cenci, E. Imbergamo, A. Nappi, M. Valdata KEK M.
Kobayashi Kyoto University of Education R.
Takashima Kyoto University K. Misouchi, H. Morii,
T. Nomura, N. Sasao, T. Sumida Virginia
Polytechnic Institute State University M.
Blecher, M. Pitt, B. Vogelaar University of New
Mexico B. Bassalleck, N. Bruner, D.E. Fields, J.
Lowe, T.L. Thomas University of Montreal J.-P.
Martin Thomas Jefferson National Accelerator
Facility M. Ito State University of New York at
Stony Brook I. Christidi, M. Marx, D. Schamberger
TRIUMF P. Amaudruz, E. Blackmore, A. Daviel,
M.Dixit, J. Doornbos, P. Gumplinger, R.
Henderson, J. Macdonald, T. Numao, R.
Poutissou University of British Columbia D.
Bryman, M. Hasinoff University of Virginia E.
Frlez, D. Pocanic University of Zurich P.
Robmann, P. Trüol, A. van der Schaaf, S. Scheu
Yale University G. Atoyan, S.K. Dhawan, V.
Issakov, H. Kaspar, A. Poblaguev, M.E. Zeller
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CP Violation in the Standard Model

• KOPIO will directly measure the complex CKM phase
  via K0 decay with minimal theoretical uncertainty
• This is complementary to b sector measurements,
  with different sensitivities to new physics
  contributions

KOPIO
E949, CKM
BaBar, Belle, CDF, D0
CDF, D0, LHCB, BTEV
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Limits

• Standard Model Expectation (2.6 ?1.2) ? 10-11
• Existing Limits
• Limit from
• KTeV Final Limit
• Goals for New Experiments
• KEK E391a s.e.s. lt 10-10 10-9
• KOPIO s.e.s lt 10-12 i.e. gt 50 reconstructed
  events
• Note for scale that the primary background is
  with a
  branching ratio of

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KOPIO Design Concept

• Maximally constrain each event by measuring the
  trajectory, arrival time, and energy of both
  photons from p0 decay
• Reconstruct p0 vertex and use Time-of-Flight to
  determine K0 momentum
• Working in the K0 CM separates two-body
  decays from three-body signal
• Surround the decay region with an extremely
  efficient photon 4p veto to minimize missed g

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Features of the KOPIO Experiment
Aerogel Beam g Veto
Barrel g Veto
Shashlyk Calorimeter
2 X0 Preradiator
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Expected KOPIO Performance

• Plotting reconstructed p0 energy in the K0 rest
  frame vs. the asymmetry in photon energies shows
  separation of signal and p0 p0 background

If occurs at the SM rate,
KOPIO expects to observe 50 events with S/N
ratio gt 2
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KOPIO RD Snapshots

• 2002 beam tests achieved required beam pulse
  width lt 300 ps, although inter-pulse extinction
  requires additional work to reach 0.1
• Full size Preradiator modules under construction,
  extruded scintillator with holes under
  development
• 20 Calorimeter prototypes delivered and poised
  for test beam studies
• Barrel veto prototypes under test for timing,
  light yield, uniformity
• All minimal required detector performance
  parameters have been met

s 252 ps
fext 3-4
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RSVP Status

• Scientific Approval
• Approved by BNL and by the NSF through level of
  the Director
• Approved by the NSB as an MREFC Project
• Endorsed by the HEPAP Subpanel on long-range
  planning
• Technical and Management Reviews
• Positively reviewed by several NSF and Laboratory
  appointed panels
• MECO magnet system design positively reviewed by
  external expert committees appointed by MECO
  leadership
• Funding
• Currently operating on RD funds from the NSF
• RSVP is not in the Presidents FY04 budget,
  efforts in Congress are ongoing
• The NSF FY04 Budget Request states that RSVP
  construction will begin in FY06 with increasing
  RD support in the interim
• Schedule
• NSF funding profile shows a five-year
  construction plan completing in FY10
• NSF will provide incremental operations support
  above that needed for AGS operations in support
  of RHIC

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Outlook

• The physics potential for RSVP is robust and
  compelling.
• We expect to move into the detailed design phase
  very soon, meaning now is the perfect time for
  people to get involved.
• We look forward to extending the long and
  outstanding tradition of discovery at the AGS.