j-parc day-1 実験の状況・ 実験家から理論屋への要望
DESCRIPTION
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. - PowerPoint PPT PresentationTRANSCRIPT
J-PARC Day-1 実験の状況・
実験家から理論屋への要望T.Takahashi (KEK)
Contents1. Aproved Exp. on S=-2 @ J-PARC2. How to produce S=-2 Systems3. E05: (K-,K+) Spectroscopy4. Discussion
Approved Experiments
3 Exp. Proposals concerning to S=2 system were approved.
E03
E05
E07
Approved Proposals of the Investigation on S=2 Systems
• Spectroscopy study of -hypernucleus, 12Be,
via the 12C(K-,K+) reaction (E05)– Reaction (Missing mass) spectroscopy– -hypernuclei, -hypernuclei– -A potential at center region
• Measurement of X rays from - atoms (E03)– X-rays from - atomic states– -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 - atom– -hypernuclei, -hypernuclei
How to produce and studyS=2 systems
K + p K+ +
p(K)~1.8GeV/c
Direct productionReaction Spectroscopy
Decay measurementsEmulsion
X-rays measurements
q ~0.5 GeV/c
E05 Experiment
• Missing mass spectroscopy of 12C(K,K+)X– 12
Be, 12Be
• 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
E.S. Separators
BeamSpectrometer
K ~6.9
p/p=3.3x10(FWHM)
1.2x106 K /spill(Phase-1)
High-purity
High-intensity
High-resolution
Proton beam30GeV-9A
SksPlus Spectrometer
2.7T(395A)
~1.5T
• 95°total bend• ~7m flight path• x=0.3 mm (RMS)
0
10
20
30
40
1.0 1.2 1.4 1.6p [GeV/c]
[msr
]
~30msr
0.5
1.0
1.5
2.0
2.5
1.0 1.2 1.4 1.6p [GeV/c]
dp [M
eV/c
]
p/p=0.12%
Previous Measurement on 12C(K,K) – BNL AGS E885 –
PK=1.8 GeV/cM=9.9 MeV/c2 (FWHM) for p(K,K+)
P.Khaustov et al, PRC61(2000)0546
20 < E < 0 MeV 89±14 nb/sr < 8° 42± 5 nb/sr <14°
Evidence !? V = 14 MeV
12C(K,K+)12Be spectra
calculated by W.S. potential
P.Khaustov, et al.Phys. Rev. C61(2000)054603
V[MeV]
states
s-state [nb/sr]
0p3/20s1/2
p-states
0p3/20p3/2
0p3/20p1/2
sum
[nb/sr]
Edet=0 MeV
K.Ikeda, et al, Prog. Theor. Phys. 91 (1994) 747 ;Y.Yamamoto, et al,Prog. Theor. Phys. Suppl. 117 (1994) 281
Expected 12Be Spectrum
V= 20MeV
V= 14MeV
[cou
nts/
0.5M
eV]
-B [MeV]
s
p Emeas. = 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– T = 1
• Spectroscopy が成立する条件– ≦M
– BY > M)
– Level spacing > M)
考えられるシナリオ• 細い(1本の)ピークを観測
– Small Imag. potential• Weak N interaction
– 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)
• 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、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)
• FISを用いた N 相互作用の研究– K d K+ n– Kinematics Q.F. の End Point 近辺 ?– 断面積 0.1 b/(sr MeV) あれば可能?– どの位の分解能が必要か?
Kinematics of K d K+ n
K p n
d
Kn
0
500
1000
1500
0 0.05 0.1 0.15p [GeV/ c]
a.u.
Momentum Dist. in d
2-dim. simple model
0
0.2
0.4
0.6
0.8
1
- 0.15 - 0.1 - 0.05 0 0.05 0.1 0.15
pn [GeV/ c]
[GeV
/c]
1.8GeV/ c
1.5GeV/ c
2.0GeV/ c
Relative momentum between n and
Tokai Site of JAEA
Photo:21-Dec-2006
7-Feb-2007
23-Feb-2007
Photo:21-Dec-2006
23-Feb-2007