1 / 17

Mu anti-Mu 変換実験 ~MUWG in 熱海 ~

Mu anti-Mu 変換実験 ~MUWG in 熱海 ~. J-PARC MLF ディビジョン ミュオン 河村　成肇. 物質・生命科学実験施設. 中性子分光器. ミュオン生成標的. ミュオン科学実験施設 = 陽子ビームライン 　＋ミュオンビームライン. 中性子生成標的. 中性子分光器. 第二期ミュオン施設建設. 崩壊ミュオンビームライン（第一期建設分）. 大立体角ミュオンビームライン（第二期）. 汎用性の高い崩壊ミュオンビームライン 正負ミュオン（ 30-120MeV/c ）の輸送.

amina
Download Presentation

Mu anti-Mu 変換実験 ~MUWG in 熱海 ~

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. Mu anti-Mu変換実験~MUWG in 熱海~ J-PARC MLFディビジョン ミュオン 河村　成肇

  2. 物質・生命科学実験施設 中性子分光器 ミュオン生成標的 ミュオン科学実験施設=陽子ビームライン　＋ミュオンビームライン 中性子生成標的 中性子分光器

  3. 第二期ミュオン施設建設 崩壊ミュオンビームライン（第一期建設分） 大立体角ミュオンビームライン（第二期） 汎用性の高い崩壊ミュオンビームライン 正負ミュオン（30-120MeV/c）の輸送 表面ミュオン（30MeV/c）に特化し、軸収束のビームラインで大立体角、高輸送効率を狙う。

  4. 大立体角ミュオンビームライン 大立体角ビーム実験エリア

  5. ミュオンビーム強度 • 崩壊ミュオンビームライン（１ＭＷ時） • 30MeV/c 3×107m+/秒 6×105m-/秒 • 60MeV/c 5×106m+/秒 1×106m-/秒 • 120MeV/c 2×107m+/秒 1×107m-/秒 • 大立体角ミュオンビームライン（第二期計画） • 30MeV/c 5×108m+/秒 1×107m-/秒 • 大立体角ビームラインによる高強度化

  6. NuFact’00 青木 物理のイントロ • Lepton Flavor Violation (LFV) • |DLi| = 1 • |DLi| = 2 SUSY-GUT Exotic processes

  7. NuFact’00 青木 モデル (a) doubly charged Higgs boson, (b) heavy Majorana neutrinos, (c) a neutral scalar, e.g., a supersymmetric τ-sneutrino, or (d) a bileptonic flavor diagonal gauge boson

  8. NuFact’00 青木 PSIでの実験 • Setup

  9. NuFact’00 青木 PSIでの実験 • Result

  10. NuFact’03 松田 Slow muons • Slow muons : muons which are (re-)accelerated from the muons which are almost at a rest. • Beam energy is tunable, and its spread is very small. a The range in the material is tunable down to sub mm. • Emittance is very small. a Small sample can be used. • New application of mSR for thin films • Possible application towards future muon/neutrino sources

  11. NuFact’03 松田 Two methods to generate slow muon beam • Cryogenic moderator method (PSI) • Use a layer of solid rare gas as a moderator. • Initial energy is 10-100eV, and its spread is around 10eV. • Time structure is determined by initial beam. • Laser resonant ionization method • Obtain slow muons by ionizing thermal muoniums emitted from a hot tungsten film. • Initial energy is around 0.2eV, and its spread is less than 1eV. • Time structure is determined by laser timing. g Gives better time resolution for pulsed beam. gPossible use for Mu anti-Mu conversion experiment as a sensitive detection method of anti-Mu and background suppression.

  12. NuFact’03 松田 Slow-muon beam-line at RIKEN-RAL

  13. NuFact’03 松田 Slow-muon beam-line at RIKEN-RAL

  14. NuFact’03 松田 Efficiency of slow muon generation Observed slow muon signal : 3.3 m/sec (MCP efficiency 66%) a 5.0 m/sec (Decay in flight 43%) a 8.6 m/sec (Transport efficiency unknown. assume 100%) a >8.6 m/sec at the source Initial surface muon beam : 1.0x106m/sec Efficiency 8.6/1.0x106 = 8.6x10-6 (still low…)

  15. NuFact’03 松田 Future plan for slow muon • Beam study • Beam profile measurement ( Segmented MCP, Slit, emittance measurement) • mSR study • Scintillator telescopes installation around the MCP chamber. • Helmholtz coil installation • Thinking of fundamental physics… • Mu1anti-Mu conversion experiment : double coincidence between laser irradiation and anti-Mu detection will reduce background significantly. • PSI experiment accumurated 5.7x1010 muonium decays. We need significant improvement of slow muon yield. • Muon intensity improvement : J-PARC, new proton driver, new design of capture channel. • Muon to muonium conversion improvement : cyclotron trap

  16. NuFact’03 松田 Cyclotron trap • PSI & LEAR application • Winding up the range path of stopping particles inside a weak focusing cyclotron field. It has been used for producing low energy negative muons beams, pions and anti-protons. • Moderator can be gas (typically ~1mbar Hydrogen), or thin metal foils. • Application for positive muons have been limited because of high capture rate of electron. • Cyclotron trap + laser ionization • Can expect increase of muon stopping density at the near-surface of Tungsten foil. • We will lose muon polarization. This will limit application for mSR, but is good for Mu 1 anti-Mu oscillation experiment. • Recover muon polarization with polarized laser light?

  17. まとめ • J-PARC MLFの大立体角ミュオンビームラインを使い、Mu-antiMu実験ができる。超低速ミュオンビームラインとほとんど同じ装置で逆のpolarity。 • 5×108 surface m+/s ×10-5 (m+→slow m+)5×1010 Mu/0.5y（2×107 Mu/s=2×1012 Mu/d） • 現状(1MW)でも、半年程度でPSIと同程度の統計。Laserとの同期で散乱からくるBGはなし。ただし、in-flightでのm-e崩壊などが問題になる？ • Mu-antiMu変換はいつ起こる？Laserを打つタイミングは？

More Related