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J-PARC Day-1 実験の状況・ 実験家から理論屋への要望. Contents 1. Aproved Exp. on S=-2 @ J-PARC 2. How to produce S=-2 Systems 3. E05: (K-,K+) Spectroscopy 4. Discussion. T.Takahashi (KEK). Approved Experiments. E03. E05. E07. 3 Exp. Proposals concerning to S= - 2 system were approved.
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J-PARCDay-1実験の状況・実験家から理論屋への要望J-PARCDay-1実験の状況・実験家から理論屋への要望 Contents 1. Aproved Exp. on S=-2 @ J-PARC 2. How to produce S=-2 Systems 3. E05: (K-,K+) Spectroscopy 4. Discussion T.Takahashi (KEK)
Approved Experiments E03 E05 E07 3 Exp. Proposals concerning to S=-2 system were approved.
Approved Proposals of the Investigation on S=-2 Systems • Spectroscopy study of X-hypernucleus, 12XBe, via the 12C(K-,K+) reaction (E05) • Reaction (Missing mass) spectroscopy • X-hypernuclei, LL-hypernuclei • X-A potential at center region • Measurement of X rays from X- atoms (E03) • X-rays from X- atomic states • X-A potential at surface region • Systematic study of double strangeness systems with an emulsion-counter hybrid method (E07) • Decay (Invariant mass spectroscopy) • X-rays from X- atom • LL-hypernuclei, X-hypernuclei
How to produce and studyS=-2 systems K- + p -> K+ + X- p(K-)~1.8GeV/c Dq ~0.5 GeV/c Direct production Reaction Spectroscopy X-rays measurements Decay measurements Emulsion
E05 Experiment • Missing mass spectroscopy of 12C(K-,K+)X • 12XBe, 12LLBe • K1.8 beamline & SksPlus spectrometer • 1.8 GeV/c K- & ~1.3 GeV/c K+ • Missing mass resolution of ~3 MeV/c2 • Energy and width of bound states • To establish methodlogy on spectroscopy of S=-2 systems
K1.8 beamline at J-PARC 1.2x106 K- /spill (Phase-1) High-intensity Beam Spectrometer Dp/p=3.3x10-4(FWHM) Proton beam 30GeV-9mA High-resolution E.S. Separators High-purity K-/p- ~6.9
~30msr SksPlus Spectrometer 2.7T(395A) ~1.5T Dp/p=0.12% • 95°total bend • ~7m flight path • Dx=0.3 mm (RMS)
Previous Measurement on 12C(K-,K+) – BNL AGS E885 – PK=1.8 GeV/c DM=9.9 MeV/c2 (FWHM) for p(K-,K+)X- P.Khaustov et al, PRC61(2000)0546 -20 < EX < 0 MeV 89±14 nb/sr q< 8° 42± 5 nb/sr q<14° Evidence !? V = -14 MeV
12C(K-,K+)12XBe spectracalculated by W.S. potential DEdet=0 MeV K.Ikeda, et al, Prog. Theor. Phys. 91 (1994) 747 ; Y.Yamamoto, et al, Prog. Theor. Phys. Suppl. 117 (1994) 281 P.Khaustov, et al. Phys. Rev. C61(2000)054603
VX= -20MeV p X [counts/0.5MeV] s X VX= -14MeV -BX [MeV] Expected 12XBe Spectrum DEmeas. = 3 MeVFWHM One momth Data-taking
(K-,K+) reaction spectroscopy • 生成チャンネルを見る • 基底状態・励起状態の観測 • 多くの標的への適応可能性 • DT = 1 • Spectroscopyが成立する条件 • G ≦DM • BY＞G(DM) • Level spacing ＞G(DM)
考えられるシナリオ • 細い（１本の）ピークを観測 • Small Imag. potential • Weak XN->LL interaction • X binding energy • Potential (Real) depth • ピーク構造が観測されない • 幅が広い • 複数の状態が励起している。 • Spin-doublet • Core excited states Spectroscopyが成立 ー＞他の標的へ
理論の人に尋ねたい一緒に考えたいこと（１）理論の人に尋ねたい一緒に考えたいこと（１） • どのような状態が考えられるのか？ • Spin/Isopin • 生成断面積は？ • 素過程のamplitude • spin-flip/spin-non-flip • 幅が広いとき、LL核は直接反応でどの程度生成されるのか？
理論の人に尋ねたい一緒に考えたいこと（２）理論の人に尋ねたい一緒に考えたいこと（２） • ＦＩＳを用いたXN相互作用の研究 • K- d -> K+X- n • Kinematics Q.F.のEnd Point 近辺? • 断面積 0.1 mb/(sr MeV)あれば可能？ • どの位の分解能が必要か？
Kinematics of K- d -> K+X- n 2-dim. simple model p n K+ K- n X- d Relative momentum between n and X- Momentum Dist. in d
