SKS@J-PARC J-PARC Project Office Day-1 @J-PARC New - PowerPoint PPT Presentation

SKS@J-PARC １年の動き 永江知文（J-PARC Project Office）

Day-1 実験@J-PARC New Generation Spectroscopy of Hadron Many-Body Systems with Strangeness S=-2 and -1 (K-,K+) for Ξ -hypernuclei (K-, π -) γ with HyperBall-3

ΞHypernuclei with (K-,K+) � � � � � � � SDC3 SDC4 TOF AEROGEL CERENKOV LUCITE CERENKOV TARGET 1200 MeV/c BEAM 1100 MeV/c 0 1 m

(K-,K+) Spectroscopy 2 MeVFWHM resolution ~6 events/day/MeV for 50 msr, 2g/cm2 thick Pb ~20 days 58 Ni(K-,K + ) 208 Pb(K-,K + ) Folding Folding Woods-Saxon Woods-Saxon V0=-24 MeV V0=-24 MeV V0=-16 MeV V0=-16 MeV Ξ - bound region Ξ - bound region M HY -M A (MeV) M HY -M A (MeV)

Ξ hypernuclei potential ? Λ , Σ -, Ξ -, K- in Neutron Star Core ? 2 µ B = m B + k F Chemical Potential: + U ( k F ) 2 m B U Σ <0, U Ξ <0 Ξ - Σ - Λ U Σ >0, U Ξ <0 Ξ - Λ U Σ >0, U Ξ >0 Λ K- u = ρ / ρ 0 Σ Ξ

Energy Spectrum of S=-2 systems Ξ -hypernucleus A-1 (Z-1)+ Ξ − B Ξ (A-1) g.s. ⊗ P Ξ Ξ− N Interaction (A-1) g.s. ⊗ S Ξ A-2 (Z-2)+ Λ + Λ B Λ A-1 Λ (Z-2)+ Λ Double- Λ hypernucleus 2xB Λ B ΛΛ (A-2) g.s. ⊗ S Λ P Λ A-1 ΛΛ (Z-2)+n ∆ B ΛΛ (A-2) g.s. ⊗ S Λ 2 ∆ B ΛΛ > 0 ? ∆ B ΛΛ < 0 ? Λ Λ M H > 2xM Λ - B ΛΛ Λ−Λ Interaction M H < 2xM Λ - B ΛΛ Weak Decays H particle mass H + (A-2)

Entrance to the S=-2 World  Doorway Reaction: K-+p → K++ Ξ - at 1.8 GeV/c

SKS@K1.8

Energy Resolution  2 MeVFWHM resolution 2 + β K − 2 + Δ E straggling Δ E 2 = β K + 2 × Δ p K + 2 × Δ p K − 2 Δ p / p K − = 2 × 10 − 4 Δ p / p K + = (0.96 ± 0.13) × 10 − 4 p K + (0.092 ± 0.007)(%) 1.89 2 + 0.31 2 + 0.5 2 = 2 MeV FWHM ∴Δ E ~  Limited by the SKS resolution  Widths of the Ξ bound state < 1 MeV?

Yield Estimation  50 msr, 2g/cm2-thick Pb Y = I Beam × 2 g / cm 2 /208 g × N A × d σ d Ω × ΔΩ× f decay × f eff = 10 7 × (2/208) × 6.02 × 10 23 × 0.1 × 10 − 30 × 0.05 × 0.5 × 0.5 events / sec ≅ 6 events / MeV / day

Issues in Ξ A potential  A-dependence of Ξ A potential depth  Strong p-wave attraction  Ξ- 207Tl > 2x Ξ- 11 B  Isospin dependence  How strong is the Lane term ?  Ξ -p- Ξ 0n mixing  Width and ΞN-ΛΛ coupling

マンパワー 応田→理研 (; ;) 高橋←J-PARCでのSKSを用いたハイ パー核実験担当の助教授 (^^) 新たな気持ちで

予算 １ 特定領域科研費の申請 代表者：岡真 ストレンジネスで探るクォーク多体系 H16~H21、総額16.6億円

予算 ２ KEK からの来年度概算要求 PS シャットダウンに伴う予算要求 SKS の移設費用も含まれる

エネルギー分解能の最適化 目標：2 MeV(FWHM) SKS 入り口部の磁気光学系の設計 QDD or QD 立体角を失わないように Beam Spectrometer の設計のつめ

測定器系の開発 速い飛跡検出器の開発 10 7 /sec./cm 2 トリガーの強化？ 現状：~400 trig./spill DAQ

N P 04 The 3rd International Workshop on Nuclear and Particle Physics at J-PARC 50-GeV PS O rganizing Institutes: High E nergy A ccelerator Research O rganization (K E K ) Japan A tomic E nergy Research Institute (JA E RI) Strangeness N uclear Physics Ex periments N uclear/ Hadron Physics Ex periments N eutrino Ex periments Kaon Rare Decay Ex periments Muon Rare Decay Ex periments Physics w ith Low -Energy Anti-Protons ug. 2 - 4, 2004 at Tokai, Ibaraki, Japan Local organizing committee A S.Nagamiya (KEK/JAERI; Chairperson) K.Imai (Kyoto) J.Imazato (KEK) ug. 24 - 26, 2004 at K A E K (Neutrino session) T.Kobayashi (KEK) T.Komatsubara (KEK) T.Nagae (KEK) K.Nishikawa (Kyoto) http://j-parc.jp/NP04 Contact: S.Sawada (KEK) T.Takahashi (KEK; Scientific secretary) takahasi@lambda.phys.tohoku.ac.jp M.Takasaki (KEK) takashi.kobayashi@kek.jp (Neutrino) T.Yamanaka (Osaka) Photo:J-PARC site taken in Feb. 2004

今年度やるべきこと NP04 Full Proposal の準備 科研費申請のstrategy