Recent experiments on three nucleon systems and problems to be solved

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FB19
Recent experiments on three nucleon systems and
problems to be solved
Kenshi Sagara Kyushu U. , Fukuoka, Japan
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Experiments in Nd system
Basic process
High momentum transfer

Various configurations QFS, FSI, Star, Collinear,
..
Calculatons with 2NF3NF
3-nucleon forces 3-body effects
Systematic experiments

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Discrepancies in 3N systems and their origins
-- lower energy discrepancies --
Ay puzzle 1986
Systematic measurements
???
Ay puzzle
-- higher energy discrepancies --
pd sactt. discrepancy
3N BE problem 1980s
FM-3NF 1957
pp3NF(FM) was found 1998
pr3NF? rr3NF? relativity?
pd breakup discrepancy
pd CS discrepancy 1994-1996-1997 (Sagara
discrepancy)
Faddeev eqs. 1960
pd capture Ajj anomaly
-- lower energy discrepancies --
Space Star anomaly 1989
Off-plane Sar anomaly QFS anomaly
???
We are here.
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Ay puzzle
Ay at EN 5-18 MeV (1994)
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A suggestion to solve Ay puzzle
Modified calculations
Original calculation
Modification factors
NN forces 3P0 3P1 3P2
np 1.04 1.07 1.03
pp 0.86 1.05 1.02
nn 0.75 1.08 1.03
H. Witala and W. Gloeckle, NPA528 (1991)48
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Modification of LS force in 2NF Modification of
3PJ forces in 2NF Addition of LS force in
3NF Adjusting of forces in cPT
Ay puzzle
Origin(s)
3NF effects? Relativistic effects? or ..
Ay puzzle is a long-standing problem since 1986
(FB11).
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Shortage of 3H binding energy (1980s)
(Theory)
(Experiment)
2NF
8.482MeV
1MeV shortage
3H B.E. can be reproduced by adjusting a
parameter L in 2p3NF
Another evidence was necessary to confirm 2p3NF
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Systematic measurement of pd scattering cross
section (1994)
5MeV
12MeV
10MeV
18MeV
Here are discrepancies
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pd cross section (RIKEN 1996)
30 difference
nd calculation by Koike
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Koikes talk at FB15 (KVI)
RIKEN data (1996)
Kyushu data (1994)
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Scattering cross section
Binding energy
2NF
8.482MeV (exp.)
2p3NF
2p3NF
H.Witala et al., Phys Rev Lett. 81 1183(1998)
41 years
2p3NF was found (1998)
Fujita-Miyazawa (1957)
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Discrepancies in 3N systems and their origins
-- lower energy discrepancies --
Ay puzzle 1986
Systematic measurements
???
Ay puzzle
-- higher energy discrepancies --
pd sactt. discrepancy
3N BE problem 1980s
FM-3NF 1957
pp3NF(FM) was found 1998
pr3NF? rr3NF? relativity?
pd breakup discrepancy
Faddeev eqs. 1960
pd CS discrepancy 1994-1996-1997 (Sagara
discrepancy)
pd capture Ajj anomaly
-- lower energy discrepancies --
Space Star anomaly 1989
Off-plane Sar anomaly QFS anomaly
???
We are here.
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pd capture experiment
? high momentum transfer ? short-range 3NF
Reaction cross section is very small (lt 1 m barn).

• Experimental techniques
• thick target low BG ? liquid hydrogen target
• high-efficiency detection ? one-shot measurement
  of whole
• angular distribution

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Liquid Hydrogen Target
????????
mm
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(No Transcript)
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q(3He) lt 4.7?
Vertical plane for Axx
Horizontal plane for Ayy Ay
Whole angular distribution was measured in one
shot.
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BG level was low
Y
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Axx anomaly in pd capture at Ed 200 MeV from
RCNP exp. (Yagita et al. 2002)
2NF
Calc. by Witala et al.
2NF3NF
Axx anomaly? AxxAyy?
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Ajj of pd-capture were measured also at KVI, and
KVI data agreed with calculations.
Axx
Ayy
? ? RCNP(200MeV) ? KVI (180MeV)
Azz
RCNP data at 137MeV also disagreed with KVI
data at 133MeV.
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Experiment at KVI, Ayy Azz (-Axx-Ayy )
Big-Bite spectrometer (BBS) Plastic
Ball detector (PB)
g-detection Azz 4510 degree Ayy 015 dergree
Azz -Axx-Ayy
Beam axis
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Re-measurement at RCNP at 200 MeV
d p?3Heg Ed 200 MeV q(3He) lt 4.7deg
Slit in front of LAS
Beam polarization is along y-axis.
Azz (Axx-Ayy)
Ayy
Axx
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Background subtraction
y
polarized beam
True
Liuqid target
BG
y
unpol. beam
Empty target
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Detection efficiency
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Backgroun estimation was much improved by a
multi-II method.
X1
Single cluster
83
X2
Efficiency .834 0.48 Standard data analysis
X1
Multiple cluster
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X2
Efficiency .974 0.88
X1
Overlapped cluster single cluster
2
X2
Efficiency .994 0.96 Multi-II data analysis
X1
Overlappedoverlapped cluster Other rays
1
X2
Total 100
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Single cluster data analysis vs. Multi-cluster
II data analysis (new)
2002 exp.
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dp?3Heg
New data and previous data (new multi-II analysis)
present
2002
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dp?3Heg
New data and previous data (Multi-II)
present
2002
Azz
-(AxxAyy)
-(AxxAyy)
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(No Transcript)
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pd radiative capture at Ed 137 MeV (multi-II
analysis)
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Ajj in pd capture
Axx anomaly (Azz anomaly) has been confirmed.
Axx Ayy ---gt axial symmetry ? Azz gt
calculation ----gt short range reaction?
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pd scattering CS at 250 MeV
E-dependence of CS at 150 degree
exp/cal at q 150
2p3NF
q150
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J. Kuros-Zoluierczuk et al., PRC66, 024003
(2002).
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D(p,pp)n CS at 250 MeV
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Inclusive exp. at 250 MeV D(p,p)pn experiment
(global feature)
un-detected
p
d
p
detected
Exclusive exp. at 250 MeV D(p,pp)n experiment
(microscopic study)
p
detected
p
d
p
detected
--gt Kuroitas talk
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pd nd scattering CS above 150 MeV
pd breakup CS at 250 MeV, inclusive exclusive
Short-range 3NF? Relativity? ..?
Large (2 times) CS enhancement
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Space star anomaly around 10 MeV
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a144º
a124º
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QFS anomaly?
QFS
QFS
En
Is there QFS anomaly in addition to space star
anomaly?
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Result (pp-QFS)
Ep 13 MeV
Ep 9.5 MeV
star
QFS
QFS
7 smaller
9 smaller
preliminary
preliminary
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Ep 9.5 MeV
Ep 13 MeV
pd QFS
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Also there are nd QFS (2002,2007), and CS of nd
QFS is higher than calculation, CS of pd QFS is
lower than calculation.
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Angular dependence of QFS anomaly
Ep 9.5 MeV
?
?
?
?
?
?
?
Ep 13 MeV
1
2
3
4
7
6
5
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Nd breakup cross section at low energy
Star anomaly
Star anomaly appears only around space star (a
90 ) at 13 MeV, and in a wide angular region
at 9.5MeV. Large CSB occurs, nd CSgt calc, and
pd CS lt calc.
What origin(s) Same origin or different ones?
QFS anomaly
CS anomaly also appears in pd QFS and nd QFS.
QFS anomaly appear s in a wide angular region.
Large CSB occurs, nd CSgt calc, and pd CS lt
calc.
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Discrepancies in 3N systems and their origins
-- lower energy discrepancies --
Ay puzzle 1986
Systematic measurements
???
Ay puzzle
-- higher energy discrepancies --
pd sactt. discrepancy
3N BE problem 1980s
FM-3NF 1957
pp3NF(FM) was found 1998
pr3NF? rr3NF? relativity?
pd breakup discrepancy
Faddeev eqs. 1960
pd CS discrepancy 1994-1996-1997 (Sagara
discrepancy)
pd capture Ajj anomaly
-- lower energy discrepancies --
Space Star anomaly 1989
Off-plane Sar anomaly QFS anomaly
???
We are here.
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More systematic experiments on some reactions

More challenging calculations with new 3NF, new
frame,
remaining 3NFs unknown 3-body effects .