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MuSun Tracking Challenge

MuSun Tracking Challenge. Muon stop parameters Fake stops by m +p scattering Fusion interference. GEANT 10x10 pad. GEANT. MuCap TPC. Impurity tagging. m tracking acceptance must be independent of fusion time t f after m. Fusions. Observables in MuSun experiment. Fusion channels.

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MuSun Tracking Challenge

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  1. MuSun Tracking Challenge • Muon stop parameters • Fake stops by m+p scattering • Fusion interference GEANT 10x10 pad GEANT MuCap TPC Impurity tagging m tracking acceptance must be independent of fusion time tf after m

  2. Fusions Observables in MuSun experiment Fusion channels mN capture n (2.45) 3He (0.82) 0.2 mm m3He (0.80) n 0.6 mm t (1.01) p (3.02) 16 mm 1mm

  3. em must be independent of tf e time f m

  4. Pulse shape depends on angle to horizontal plane

  5. Weak muon + fusion

  6. Split He or mHe

  7. p+t

  8. Strategies • Just energy cut, rough granularity (ok, if we catch all m) • Identify muon track • Ignore He, mHe at the end • Accept if two tracks, i.e. m+p candidate This allows to select ~ horizonal muons • Other Justin’s MC has to be convoluted with measured noise, then the track finders have to compete !

  9. Gas Purity (Z-1)* + n • CirculatingHydrogenUltrahighPurificationSystem(CHUPS) US CRDF 2002, 2005 • New: • cryo-TPC • cryo filter before TPC • continuous getter in gas flow for gas chromatography • Particle detection in TPC much harder – fusionfor MuSun – m signal 1 MeV • excellent TPC resolution • full analog readout • tags – p after capture – X-ray • protium measurement Rare impurity capture:md + Z d + mZ  (Z-1)* + n MuCap achieved: ~ 10 ppb purity and 0.1 ppb purity monitoring MuSun needs: ~ 1 ppb purity or 0.5 ppb purity monitoring

  10. Peter Kammel for the MuSun Collaboration Muon Capture on the Deuteron The MuSun Experiment BV39, Feb 21, 08

  11. Collaboration V.A. Andreev, V.A. Ganzha, P.A. Kravtsov, A.G. Krivshich, E.M. Maev, O.E. Maev, G.E. Petrov, G.N. Schapkin, G.G. Semenchuk, M.A. Soroka, A.A. Vasilyev, A.A. Vorobyov, M.E. Vznuzdaev Petersburg Nuclear Physics Institute, Gatchina 188350, Russia D.W. Hertzog, P. Kammel, B. Kiburg, S. Knaack, F. Mulhauser, P. Winter University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA M. Hildebrandt, B. Lauss, C. Petitjean Paul Scherrer Institute, CH-5232 Villigen PSI, Switzerland T. Gorringe, V. Tishchenko University of Kentucky, Lexington, KY 40506, USA   R.M. Carey, K.R. Lynch Boston University, Boston, MA 02215, USA   R. Prieels Universite Catholique de Louvain, B-1348 Louvain-la-Neuve, Belgium   F.E. Gray Regis University, Denver, CO 80221, USA A. Gardestig, K. Kubodera, F. Myhrer University of South Carolina, Columbia, SC 29208, USA Combined forces MuCap & MuLan

  12. Goal and Motivation m- + d  n + n + nRateLd from md() atom • MeasureLdto < 1.5 % • Simplest weak interaction process in a nucleusallowing for precise theory & experiment  nucleon FF (gP) from MuCap  ab-initio QCD calculations with effective field theory • Close relation to neutrino/astrophysics  Model-independent connection m+dto pp fusion and n+d reaction • Broader Impact on modern nuclear physics  EFT relates m+d to strong processes like p+d  g + n +n, ann

  13. m + d  n + n + nTheory Axial current reaction Gamow-Teller 3S1 1S0 • one-body currents well defined • FF, deuteron wavefunction, ann • two-body currents not well constrained by theory (short distance physics) • Methods • Potential model + MEC • Effective field theories (EFT) • pion less (q/mp) • ChPT(q/L) • hybrid EFT (EFT operators, Pot.Model wavefct) D p MEC EFT  L1A, dR

  14. m + d Experiment m   d • Experimental Challenges • Dalitz Plot Intensity at low Enn ChPT covers most of DP pEFT only pn< 90 MeV/c m → enn lm= 455162 s-1 mdq,d → n+n+nLq ~ 10 s-1, Ld = 400 s-1md() + d→ md() + dddm→ 3He + n + mrates ~ lm

  15. Precise Experiment Needed Determine L1A from clean system Ramnifications for n-astro physics Quantify consistency of hybrid approach consistent ChPT pionless, needs L1A hybrid EFT Potential Model + MEC

  16. Connection to Neutrino/Astrophysics • Basic solar fusion reaction p + p  d + e+ +  • Key reactions for Sudbury Neutrino Observatory e + d  p + p + e- (CC) x + d  p + n + x (NC) • Intense theoretical studies, scarce direct data • EFT connection to m+d capture via LEC L1A, dR • Muon capture soft enough to relate to solar reactions  with L1A ~ 6 fm3

  17. Quest for L1A, dR “Calibrate the Sun” • Precision m+d experiment by far the best determination of L1A in the theoretically clean 2-N system

  18. Muon Capture, Big Picture { gP, gA, ChPT } m + p m + d m + 3He { gP, gA, ChPT, L1A, ann } { gP, gA, hybrid EFT, L1A, 3N} Final MuCap 2-3x improvement Combinedanalysis

  19. Experimental Strategy Two main conditions • Unambiguous physics interpretation Muon kinetics  optimization of D2 conditions • Very high precision Ld to 1.2% (5 s-1) Statistics: several 1010 events Systematics !

  20. Muon Kinetics Collisional processes density f dependent, e.g. hfs transition rate from q to d state = flqd densityf normalized to LH2 density Muon-catalyzed Fusion lq lq lqd lqd ld ld lm complicated, can one extract fundamental weak parameters ?

  21. Optimize Muon Kinetics • Time Distributions • Sensitivities (Ld 1%, lx  2 sx) MuCap MuSun md md() md() m3He

  22. Use Basic MuCap Technique m → enn Ldreduces lifetime by 10-3 + log(counts) - μ+ μ – te-tm • Lifetime method 1010m→enn decays measure- to 10ppm, d = 1/- - 1/+to 1% • Unambiguous interpretation at optimized target conditions • Ultra-pure gas system and purity monitoring at 1 ppb level • Clean m stop definition in active target (TPC) • 3 times higher rate with Muon-On-Request (MuLan) MuCapTPCtop TPCside

  23. Experiment Overview e eSC ePC2 ePC1 mPC Cryo-TPC m mSC

  24. Cryo-TPC Design Criteria

  25. Cryo-TPC Design

  26. Technical Design Cryo-System Vibration free cooling Continuous cleaning

  27. Detectors and DAQ Cryo-TPC special Other detectors/infrastructure from MuCap g detectors as impurity monitor DAQ from MuCap/MuLan new: full analog TPC readout (complicated energy spectrum) 10x10 pads two 8-bit waveform digitizer channels per pad (50 MHz) 15 MB/s (4 MHz/s) beforelossless compression 2006 BU digitizer

  28. Statistics + Systematics 1.81010 events

  29. Measuring Program Stage 1 – 300 K TPC Rebuild (spare) MuCap TPC as ionization chamber Energy resolution Identification and separation of fusion recoils Full analog readout Measure md → mZ transfer rate Optimize mN capture monitor with dedicated setup Stage 2 – Cryo-TPC ?6 Ready Fall 08 Ready Fall 09 2-3 runs in total (prep. and data taking) 4 years

  30. Responsibilities & Budget • Budget estimates Total new equipment 350k CHF Annual running costs 100k CHF Heavily based on larger investments made for MuCap/MuLan • Already positive response from main funding agencies National Science Foundation, USA Russian Academy of Sciences, Russia • Full funding requests to agencies after PAC approval

  31. Request to PSI • Equipment support/year 20k CHF • Running support/year 30k CHFmagazine, small orders, PNPI visits • PSI infrastructure (Shop, Clean room), if available • “Permanent” experiment location in pE3 annex would be big advantage • First beam request 6 weeks Nov/Dec 2008 for phase I, 300K TPC

  32. Pad Optimization in Progress • Muon stop parameters • Fake stops by m+p scattering • Fusion interference GEANT 10x10 pad GEANT MuCap TPC

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