1 / 22

ORKA : The Golden Kaon Experiment

ORKA : The Golden Kaon Experiment . Physics Breadth. Elizabeth Worcester (BNL) for the ORKA collaboration June 19, 2012. Photo: Life of Sea blogspot. ORKA: The Golden Kaon Experiment. Primary physics

kimberly
Télécharger la présentation

ORKA : The Golden Kaon Experiment

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. ORKA: The Golden Kaon Experiment Physics Breadth Elizabeth Worcester (BNL) for the ORKA collaboration June 19, 2012 Photo: Life of Sea blogspot

  2. ORKA: The Golden Kaon Experiment • Primary physics • Precision measurement of K+p+nnBR with ~1000 expected events (SM) at FNAL MI • Expected BR uncertainty matches expected Standard Model uncertainty • Sensitivity to new physics at and beyond LHC mass scale • 4th generation detector building on BNL E787/E949 • Projected cost ~$53M • See David Jaffe’s talk yesterday (June 18) for details of experiment and primary physics ETW: Project X Physics Study

  3. BNL E787/E949 Stopped Kaon Technique • K+ decays at rest in the stopping target • Decay π+ track momentum analyzed in drift chamber • Decay π+ stops in range stack, range and energy are measured • Range stack STRAW chamber provides additionalπ+ position in range stack • Barrel veto + End caps + Collar provide 4π photon veto coverage ETW: Project X Physics Study

  4. ORKA Detector • Highly optimized for K+p+nn • In center-of-mass frame (kaon decays at rest) • Low momentum charged particles • Can not access all of phase space • Excellent photon veto coverage • Lots of kaons and pions ETW: Project X Physics Study Good at reconstructing pionsand muons Good at decays with missing energy Not so good at photons and electrons

  5. Primary Physics μ+ν BR 64% π+π0BR 21% • Precise BR measurement of K+p+nn • Current: • SM: • Observed signal: • K+ π+μ+e+ • Background exceeds signal by > 1010 • Requires suppression of background well below expected signal (S/N ~10) • Requires π/μ/e particle ID > 106 • Requires π0 inefficiency < 10-6 ETW: FNAL Users' Meeting II I Momentum spectra of charged particles from K+ decays in the rest frame

  6. ORKA Physics Topics ETW: Project X Physics Study ORKA physics breath document: http://projects-docdb.fnal.gov/cgi-bin/ShowDocument?docid=1644

  7. K+p+nnPNN1/PNN2 ratio • PNN1 and PNN2 kinematic regions analyzed separately • Different background and acceptance issues • If ratio of BRs measured in the two regions differs from SM, could indicate new physics • (ex: unparticles) ETW: Project X Physics Study

  8. K+p+nng -0.15% if all g undetected • Typically not experimentally measurable • For low energy g,radiative mode not distinguishable from K+p+nn • For high energy g, veto event • Expect ~0.25% of events from radiative mode when experiment can detect photon energies > 10 MeV • Expect 2-3 radiative events in 1000 event sample Mescia & Smith arXiv: 0705.2025v2 -0.4% at 10 MeV ETW: Project X Physics Study Figure 1: The QED correction to K+p+nn(g) in %, as a function of the maximum energy of the undetected photon

  9. K+p+X0 • Familon • Wilczek, Phys. Rev. Lett. 49, 1549 (1982) • Axion • arXiv:hep-ph/9807363 • Light scalar pseudo-NG boson • arXiv:0908.2004 • Sgoldstino • arXiv:hep-ph/0007325 • Gauge boson corresponding to new U(1) symmetry • Aliev et al, Nucl. Phys. B 335, 311 (1990) • arXiv:0811.1030 • Light dark matter • arXiv:0711.4866 • arXiv:hep-ph/0702176 • arXiv:hep-ph/0509024  ETW: Project X Physics Study

  10. K+p+X0 • E787/E949: B(K+p+X0) < 0.73 × 10-10 (arXiv:0709.1000) • 1 event in E949, no events in E787 • K+p+nnis a background Upper limit on K+p+X where X has listed lifetime ETW: Project X Physics Study Upper limit on K+p+X where X is stable E949

  11. K+p+X0 “event” • One event seen in E949 K+p+nnPNN1 signal region is near kinematic endpoint and also in K+p+X0signal region • Corresponds to a massless X0 • Central value of measured K+p+nn BR higher than SM expectation Generated ETW: Project X Physics Study Expected distribution of K+p+nn (MC) All cuts E949 signal event

  12. K+p+p0nn • Ke4 BR allows firm SM prediction • New physics from axial-vector in addition to vector currents • E787: B(K+p+p0nn) < 4.3 × 10-5 • Limited by trigger bandwidth and detector resolution • Expect × 1000 improvement at ORKA BNL E787 arXiv:0009055v1 ETW: Project X Physics Study

  13. K+p+gg & K+p+g • K+p+gg • B(K+p+gg) = (1.1 ± 0.3) × 10-6 • Extrapolated from 100 MeV/c < pp< 180 MeV/c region • Test of Chiral Perturbation Theory • Contributions start at O(p4) • Expect large increase in statistics (×104) • B(K+p+gg)(pp > 213 MeV/c) < 8.3 × 10-9 • K+p+g • Violates conservation of angular momentum and gauge invariance • Allowed in non-commutative/Lorentz violating theories • E949: B(K+p+g) < 2.3 × 10-9 • Expect limit to scale with exposure (× 360) O(p6) unitarity corrections No unitarity corrections BNL E949 arXiv:0505069v2 ETW: Project X Physics Study

  14. Sterile Neutrinos (nMSM) • MSM + 3 RH neutrinos • Sterile neutrinos: N1, N2, N3 • Active-sterile neutrino mixing • Lightest sterile neutrino: N1 • Mass 4-50 keV • Dark matter candidate • N2 and N3 • mix with active neutrinos ETW: Project X Physics Study

  15. Sterile Neutrinos ETW: Project X Physics Study

  16. K+m+ + missing energy arXiv:1101.1382v1 Ongoing E949 analysis (A. Shaykhiev, INR) E949 expected single event sensitivity ETW: Project X Physics Study Allowed BR(K+m+N)for normal hierarchy ORKA

  17. Precision Measurement of Ke2/Km2 • RSM = (2.477 ± 0.001) × 10-5 • Extremely precise because hadronic form factors cancel in ratio • Sensitive to new physics effects that do not share V-A structure of SM contribution • R = (2.487 ± 0.013) × 10-5 (NA62) • R = (2.493 ± 0.025 ± 0.019) × 10-5 (KLOE) • Expect ORKA statistical precision of ~0.1% • More study required to estimate total ORKA uncertainty arXiv:0707.4464  ETW: Project X Physics Study arXiv:1101.4805  arXiv:0907.3594 

  18. Fundamental K+ Measurements • K+ lifetime • Not a major source of uncertainty for unitarity tests • Some discrepancies among experimental results in PDG • B(K+p+p0)/B(K+m+n) • Contributes to fit for |Vus/Vud| • Expect improvements in lattice calculations so that experimental errors may soon be dominant ETW: Project X Physics Study M. Moulson, CIPANP 2012 x 10-8 s

  19. Dark Photons? • A´: same interactions as SM photon with reduced coupling • Multiple dedicated experiments to search for A´ at JLab • ORKA search: • K+→ p+A´→ p+e+e- • p0 → gA´→ ge+e- • Signal would appear as resonance above continuum in e+e- invariant mass distribution • Electron resolution and background from conversion could be a problem • No ORKA sensitivity estimate yet ETW: Project X Physics Study R. Essig

  20. Summary (preliminary estimate of sensitivity) • ORKA, while highly optimized for K+p+nn, is capable of making important, precise measurements of many other physics processes. ETW: Project X Physics Study

  21. Extra Slides ETW: Project X Physics Study

  22. Unparticles Georgi (arXiv: 0703260v3) Wu & Zhang arXiv: 0712.3923v1 “For large c’s, the spectra can be quite different from the SM prediction in the region when the ps are hard” SM Vector unparticle ETW: Project X Physics Study

More Related