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加速器を用いた ハドロン物理実験

加速器を用いた ハドロン物理実験. K. Ozawa (KEK). 内容. 原子核の性質 ストレンジネスで探る原子核内部 ハドロンーハドロン相互作用 原子核媒質とメソン 核子（バリオン）の中身 ストレンジバリオン Di-quark 相関. Tokai, Japan. 50 (30) GeV Synchrotron (15 m A). Material and Biological Science Facility. 3 GeV Synchrotron (333 m A). Hadron Hall. 400 MeV Linac (350m).

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加速器を用いた ハドロン物理実験

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  1. 加速器を用いたハドロン物理実験 K. Ozawa (KEK)

  2. 内容 • 原子核の性質 • ストレンジネスで探る原子核内部 • ハドロンーハドロン相互作用 • 原子核媒質とメソン • 核子（バリオン）の中身 • ストレンジバリオン • Di-quark 相関 Hadron Experiment, K. Ozawa

  3. Tokai, Japan 50 (30) GeV Synchrotron (15 mA) Material and Biological Science Facility 3 GeV Synchrotron (333 mA) Hadron Hall 400 MeV Linac (350m) 60m x 56m Neutrino Facility J-PARC (Japan Proton Accelerator Research Complex) World-highest beam intensity : ~1 MW x10 of BNL-AGS, x100 of KEK-PS Hadron Experiment, K. Ozawa

  4. Hypernuclei Strangeness d u LL, X Hypernuclei Pentaquark + He Z 6 u d -2 L, S Hypernuclei N L,X -1 SKS 0 K1.8 High p (not yet) K1.8BR KL K1.1 K meson Implantation of Kaon and the nuclear shrinkage K1.1BR Quark Ｋ− Bound quarks Free quarks Ｘray Why are bound quarks haevier？ Mass without Mass Puzzle Kaonic nucleus Kaonic atom Nuclear & Hadron Physics at J-PARC s Proton Beam Hadron Experiment, K. Ozawa

  5. South side North side KL SKS High Momentum K1.8BR K1.1BR Hadron Experiment, K. Ozawa

  6. SKS Spectrometer Q13 Q12 K1.8 BeamSpectrometer D4 Q11 Q10 Hadron Experiment, K. Ozawa

  7. 核構造とストレンジネス Hadron Experiment, K. Ozawa

  8. 原子核構造 調和振動子 井戸型 偶－偶核の第一励起準位エネルギー　 （閉殻構造、魔法数の存在） ウッド・サクソン Hadron Experiment, K. Ozawa 1体ポテンシャルによる励起準位 励起準位（調和振動子、井戸型）

  9. PRC 64 (2001) 044302 -> UL = - 28 MeV (c.f. UN = -50 MeV) ストレンジネス ストレンジネスは、Pauli Blockingを受けないので、原子核の中に置ける。 実際に、殻構造があることを実証 束縛エネルギーは、違っていた。 Hadron Experiment, K. Ozawa 1体ポテンシャルによる励起準位

  10. PRC 64 (2001) 044302 -> UL = - 28 MeV (c.f. UN = -50 MeV) ストレンジネス束縛エネルギー One example… 束縛エネルギーの違いがもたらす物理 Baryon fraction in neutron star Experimental input to models Schaffner-Bielich, NP A804 (2008). More experimental information on LN, XN, LL, SN interactions are awaited. Hadron Experiment, K. Ozawa

  11. Precise measurements of LN (E13) • g spectroscopy for light hyper nuclear using (K-, p-) reaction at pK=1.5 (or 1.1) GeV/c. • Physics: LN interaction • Charge symmetry breaking in LN interaction • 4LHe : Large CSB is suggested • sd-shell hypernuclei for A-dependence of LN interaction • 19LF : The first sd-shell hypernuclei • Confirm LN spin-dependent forces and study LN-SN coupling force • 10LB and 11LB • Physics: g-factor of L in nucleus • Spin-flip B(M1) measurement for gL in a nucleus • 7LLi : Least ambiguities and most reliable. • Hyper Ball-J is almost ready and we will take the first experimental data soon. Beam Hadron Experiment, K. Ozawa

  12. LL interaction (E07) • At KEK-PS E373, there are ~ 700 X stops and one NAGARA event is observed. • ΔBLL= 1.01±0.20 MeV for L6LHe • At J-PARC, S=-2 nuclear chart is studied by ~102LLZ via 104X--stopping events. • DBLL of several nuclides will provide definitive information on LL interaction and structure of S=-2 nuclei. • Experimental Method • (Nuclear Emulsion) The experiment is under preparations and it will be performed in the end of this year or early next year. Hadron Experiment, K. Ozawa

  13. XN interaction (E05) Expected Spectrum (Will be improved using a new spectrometer) • Discovery of X-hyper nucleus using 12C(K-,K+) reaction • 12XBe • Missing mass spectroscopy • High resolution • Originally, 3 MeV(FWHM) • 1.5 MeV will be achieved using a new spectrometer • Experiment will start in 2015 and we can expect more than 200 events of X-hyper nucleus • Precise spectroscopy Hadron Experiment, K. Ozawa

  14. ハドロンーハドロン相互作用 Hadron Experiment, K. Ozawa

  15. バリオンーバリオン相互作用 図は、八木浩輔・原子核物理学 • ストレンジネスを含む相互作用の違いの起源はどこに？ • 中性子・陽子の相互作用の研究は、 • 散乱実験 • これはストレンジネスでも可能 • ２体束縛状態（重陽子）の研究 • ストレンジネスセクターに存在しない。 Example：　陽子・中性子・重陽子の性質 中性子・陽子散乱の角分布 Hadron Experiment, K. Ozawa

  16. SN Scattering (E40) • Differential cross section of S-p and S+pscattering with 100 times larger statistics • Motivation: See “quark-Pauli effect” Hyperon production 1.3 GeV/c p+-p -> K+S+-reaction S+- track not directly measured Measure proton momentum vector -> kinematicallycomplete +p (quark Pauli) quark + meson exch meson exch Evaluation of quark Pauli effect andunderstanding the origin of the hard coreof the nuclear force New experimental techniques with MPPC and Fiber Tracker will be used Hadron Experiment, K. Ozawa

  17. メソン－バリオン相互作用（KN, E15） Experimental scheme Physics motivation Experimental setup J-PARC Future 2013, K. Ozawa Experiment is on-going

  18. Results of an engineering run XY plane YZ plane Liquid 4He inside Target-image together with material around has been reconstructed by the CDS Charged particles from the target have been successfully identified by the CDS • CDS and Liquid Helium target system successfully worked • Ready to explore kaonic-nuclei @ K1.8BR • Data Taking in this May! pp- invariant-mass spectra reconstructed by the CDS L Hadron Experiment, K. Ozawa ~10,000 Ls have been accumulated

  19. E27: Search for “K-pp” bound state in the d(p+,K+)X reaction K+ π+ Λ* • “K-pp” is produced through L* doorway in the d(p+,K+) reaction • Semi-exclusive measurement by Range Counter Array (RCA) in order to suppress quasi-free B.G. • K-pp ®Lp1, L®p2p- • K-pp ® S0p1, S0 ® (Lg) ®p2p-g • p+d ®L* K+p1s, L* ®Sp, S+ ®p2p0 n K-pp d p K+ p RCA Momproton>350MeV/c Expected point by FINUDA, DISTO Data already collected and results will be reported soon. counts (/3M beam・10days ) Hadron Experiment, K. Ozawa Missing mass d(π+,K+) [GeV/c2]

  20. 原子核媒質とメソン Hadron Experiment, K. Ozawa

  21. 媒質からの励起状態としてのハドロン • カイラル対称性の自発的破れに伴う質量の獲得 • π中間子が異常に軽い（Mp ~ 130 MeV/c2）ことは、対称性の自発的破れに伴う南部ゴールドストンボソンと理解 • 実際にカイラル対称性は破れている。 • カイラルパートナーに質量差があることが知られている 構成子クォークの質量を獲得 Mass [GeV] NGボソンとしての擬スカラー中間子 （Jp=0-） • 媒質中での中間子の測定 • 原子核媒質の性質の測定 • 原子核-中間子相互作用の測定 Hadron Experiment, K. Ozawa

  22. p束縛状態 Large overlap of wave function Sensitive to p-nucleus strong interaction potential Measure binding energy can be converted to this b1 information Hadron Experiment, K. Ozawa

  23. Exp. Results K. Suzuki et al., Phys. Rev. Let., 92(2004) 072302 • bound state is observed in • Sn(d, 3He) pion transfer reaction at GSI. Reduction of the chiral order parameter, f*p(r)2/fp2=0.64 at the normal nuclear density (r = r0 ) is indicated. Experiment is continued at RIKEN and positive results are already obtained. Hadron Experiment, K. Ozawa

  24. Other Pseudo Scalar Meson: h Calc. by H. Nagahiro, D. Jido, S. Hirenzakiet. al LOI by K. Itahashiet. al Forward neutron is detected. missing mass distribution is measured. Simulation In addition, measurements of invariant mass of N* decay Hadron Experiment, K. Ozawa

  25. Other Pseudo Scalar Meson: h’ @ GSI Reaction is similar with pionic atom experiment. Theoretical calculation by H. Nagahiro Hadron Experiment, K. Ozawa

  26. 反クォーク・クォーク凝縮量 • 反クォーク・クォーク凝縮量と関係した測定量 • ベクトル中間子や軸性ベクトル中間子の質量分布 • Weinbergtypesumrule • たとえば、自由空間中で、t粒子の崩壊からの分布の測定がある。（ALEPH, Phys. Rep. 421(2005) 191） • 自由空間以外での測定は、実験的に難しい Hatsuda, Koike and Lee, Nucl. Phys. B394 (1993) 221 Kapusta and Shuryak, Phys. Rev. D49 (1994) 4694 Hadron Experiment, K. Ozawa

  27. Example: sum rule e.g. Weinberg type QCD sum rule Hatsuda, Koike and Lee, Nucl. Phys. B394 (1993) 221 Kapusta and Shuryak, Phys. Rev. D49 (1994) 4694 ALEPH, Phys. Rep. 421(2005) 191 Hadron Experiment, K. Ozawa

  28. さらに、反クォーク・クォーク凝縮量 • QCD sum ruleをベクトル中間子の質量分布に適用し、凝縮量と関係づけられると示唆 • 実験的には、 • ベクトル中間子質量分布の測定は可能 • 原子核中や高温ハドロン物質中での測定も可能 • 内包する凝縮量の違いを反映する • 質量獲得モデルや“QCD媒質”状態予想の検証 • 自由空間以外でのベクトル中間子の質量分布測定が基礎情報として重要 Hatsuda and Lee, Phys. Rev. C46 (1992) R34 Hadron Experiment, K. Ozawa

  29. KEK-PSE325実験へ • 原子核密度に対する面白い予想の存在 • 凝縮量と質量分布の関係と以下の仮定を基に予想 • 質量分布の形 • 凝縮量の変化の効果をポール位置の変化に集約 • 核子内の凝縮量の評価 • 凝縮量は、密度に線形に変化 • 原子核中で、18％（ρ, ω）と1.8%（φ）の質量変化を予測 • 実験的に検証可能 • 原子核中での崩壊により質量分布を測定 • 終状態相互作用を避けるために電子対崩壊を選択 • バックグランドやρ-ω干渉に関する不定性を避けるため、φ中間子に対して測定 • φ中間子の幅は狭い（ 4.3 MeV/c2 ）。質量変化が測定しやすい。 • あらわなハドロン相互作用の効果は小さい。 • e.g. Binding energy of fN is 1.8 MeV (Phys. Rev. C 63(2001) 022201R) Hatsuda and Lee, Phys. Rev. C46 (1992) R34 Hatsuda and Kunihiro, Nucl. Phys. B387 (1992) 715 Hadron Experiment, K. Ozawa

  30. KEK-PSE325実験の概要 12 GeV proton induced. p+A f + X Electrons from f decays are detected. • Target • Carbon, Cupper • 0.5% rad length KEK E325 Hadron Experiment, K. Ozawa

  31. Clear measurements of f meson at KEK-PS. The only one measurement on medium modification of f meson. bg<1.25 (Slow) R. Muto et al., PRL 98(2007) 042581 Cu Decays outside nucleus Decays inside nucleus • meson has NO mass modification • Blue line shows expected line shape including all experimental effects • wo mass modification • meson has mass modification • Modification is shown as an Excess e+e- invariant mass Indication of QCD-originated mass modification! Hadron Experiment, K. Ozawa

  32. bg<1.25 (Slow) 1.25<bg<1.75 Target/Momentum dep. • Two nuclear targets: • Carbon & Copper • Inside-decay increases in large nucleus • Momentum bin • Slowly moving f mesons have larger chance to decay inside nucleus Only one momentum bin shows a mass modification under the current statistics. To see clear mass modification and establish QCD-originated effects, significantly larger statistics are required. Same as previous slide Excess e+e- invariant mass Hadron Experiment, K. Ozawa

  33. KEK-PS E325で得られたもの • 原子核中でのφ中間子の質量分布変化を示唆するデータ • 得られた分布をφ中間子の質量ピーク位置の変化として解釈すると、3%の変化 • 初田-Lee予想とConsistentだが、偶然かもしれない。 • 核子内の<ss>凝縮量は、非常に小さいというLatticeの計算（H. Ohki et. al, Phys. Rev. D 78(2008) 054502） • 密度に対する凝縮量の線形近似 • 中間子生成過程、中間子崩壊点の密度の不定性 Hadron Experiment, K. Ozawa

  34. 次に、何を目指すか？ • KEK-PS E325の結果のConfirm • 世界的にも、他にφ中間子の結果は得られていない。 • 原子核密度における質量分布の確立 • 凝縮量との関係に対する議論に耐えられるデータ • 生成過程、密度分布などの不定性の小さいデータ • 単なる質量分布を超えた測定 • 媒質中で質量に対応するものは、エネルギーと運動量の分散関係 Hadron Experiment, K. Ozawa

  35. J-PARCでの実験の目標 Momentum Dependence A clear shifted peak needs to be identified to establish QCD-originated effects Pb E325 results Extrapolate Proton 凝縮量の評価を可能にする高統計測定 Hadron Experiment, K. Ozawa

  36. Pb f Modified f [GeV/c2] Invariant mass in medium さらに、 f f f f f f f f f from Proton p dep. Dispersion relation Hadron Experiment, K. Ozawa

  37. Experimental set up Construct a new beam line and new spectrometer Cope with 1010 per spill beam intensity (x10) Extended acceptance (90 in vertical) (x5) Increase cross section (x2) Deliver 1010 per spill proton beam Primary proton (30GeV) beam New high momentum beam line Hadron Experiment, K. Ozawa

  38. 100x100 200x200 300x300 Detector components HBD (Hadron-Blind Cherenkov detector ) GEM Tracker • Key Technology: • CsI evaporated GEM as a photo cathode • Q.E. of 40% is achieved Position resolution of 100m is achieved • Both detectors based on Gas Electron Multiplier (GEM) technology • Recently, we succeed making a proto-type which meets our experimental requirements. • Now, we are preparing a mass production of detectors. Hadron Experiment, K. Ozawa

  39. s s Φ K+ s u u s u u p Λ d d E29: f bound state? Mass shift of f in nucleus can produce a bound state? Production pp -> ff Detection fp -> K+L J. Yamagata-Sekihara, D. Cabrera, M. J. Vicednte-Vacas, S. Hirenzaki; 'Formation of Φmesic nuclei'; Progress of Theoretical Physics 124, 147-162 (2010).  Hadron Experiment, K. Ozawa

  40. p-A   + n+X n p p0g g  w p0 g g E26: Omega in nucleus • Measurements of w meson in nucleus • Production of w is also measured • Focus on low momentum w meson H. Nagahiro et al, Calculation for 12C(p-, n)11Bw Missing Mass (Bound state?) • Construct • Neutron counter • Gamma Detector • Beam Momentum is 2.0 GeV/c • It can be done at K1.8 and • also at new high momentum beam line Invariant Mass Hadron Experiment, K. Ozawa

  41. ハドロン内部構造 Hadron Experiment, K. Ozawa

  42. アイソスピン対称性・クォークモデル 陽子：　 ｜1/2, ＋1/2＞, S = 0 中性子：｜1/2, －1/2＞, S = 0 π中間子：　I=1の3重項, S = 0 Baryon 但、クォークの数を３つとする原理的理由はない。 p+p, p-p反応の断面積 Particle Data Book, Phys. Let. B667(2008), 1 Hadron Experiment, K. Ozawa

  43. E19:Penta quark - results 2010 data Search for the Θ+ via the p+π-→K-+XReaction at 1.97GeV/c No peak of Q+ was observed. U.L. (90%CL) 0.26mb/sr (2－14°) in 1.51－1.55GeV/c2 U.L.(90%CL) of GQ 0.72 MeV (1/2+) 3.1 MeV (1/2-) PRL 109 (2012) 132002 PRL published Updated data with higher beam momentum exists. See Dr. Naruki’s talk. Hadron Experiment, K. Ozawa

  44. H dibaryon search (E42) • The observation of several double-Lhypernuclear events in nuclear emulsion suggests that the H-dibaryon is very closely bound or unbound relative to 2mL . • Some experimental results show an enhancement just above 2mLmass (~ 2250 MeV/c2). • J.K. Ahn et al., PLB 444 (1998) 267 • C.J. Yoon et al., PRC 75 (2007) 022201(R) • Weakly-bound : H -> Lpp • Virtual state : LL threshold effect • Precise measurements of LL and Lpp productions in 12C(K-, K+) reactions are proposed. • Forward K spectrometer and a time projection chamber around the target is used. Experimental setups Expected spectrum for a virtual state Hadron Experiment, K. Ozawa

  45. クォーク・反クォーク　ポテンシャル Coulomb Potential (Positronium)との比較 q-q ポテンシャル 実線：-a/r + br、破線: a・ln(br) Charmonium　（c-c） の励起状態 Martin and Shaw, Particle Physics Harmonic Oscillator型Potentialの励起状態 Hadron Experiment, K. Ozawa

  46. Diquarks Baryons as well as Mesons seem to be well described by a Rotating String Configuration with a universal string tension. Mesons Baryons M2∝1.1L M2∝1.1L M2 (GeV2) L L

  47. Emergent Diquarks Baryons as well as Mesons seem to be well described by a Rotating String Configuration with a universal string tension. “diquark” in low-lying modes qq q

  48. Heavy quark baryon l: orbital motion r: di-quark correlation • When single quark picture is still a good picture, excited states are degenerated. • If Cqq (q=u,d) system is considered as C and di-quark correlations, orbital motion of l is lowered due to the collectivity of the di-quark motion. • Spin correlations between light quarks give additional level separations. • Level pattern tell us: • Mass of di-quark • Strength of di-quark correlation • Spin dependent correlation between light quarks Measurements of all levels are important Hadron Experiment, K. Ozawa

  49. Missing mass Spectroscopy 2.3 Tm Dipole K+ DC PID • Large Acceptance, Multi-Particle • K, pfrom D0 decays • Soft p from D*- decays • (Decay products from Yc*) • High Resolution • High Rate • SFT/SSD op. >10M/spill atK1.8 Use forward D mesons production No Bias measurements up to 3GeV/c2 of Charmed Baryon mass H2 TGT PID Beam p- DC High rateTrackers (Fiber, SSD) p- p- TOF LAMPS Hadron Experiment, K. Ozawa

  50. Expected Spectrum in the (p,D*-) reaction (GeV/c2) Lc(2940) ?? D*N Signal: 1 nb/Yc* :~1000 events BG: 1.8 mb (JAM) 2.9 Sc(2800) ?? Lc(2880) 5/2+ DN 2.8 pSc DN D*N 2.7 Lc(2880) Lc(2625) 3/2- Lc(2625) Lc(2940) Lc(2595) Lc+ 0.8GeV Sc(2800) 2.6 pSc Sc(2455) Lc(2765) Sc(2520) Lc(2595) 1/2- Sc(2520) 3/2+ Lc Sc(2455) 1/2+ pLc 2.4 Lc 1/2+ 2.3 Missing Mass (GeV/c2)

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