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Systematic Experiments on Unsolved Anomalies in 3N breakup Reactions Kenshi Sagara ( Kyushu University). +. g. +. +. +. 3N bound state. Scattering & reactions. +. Discrepancies in 3N systems and their origins. lower energy discrepancies. Ay puzzle 1986. Ay puzzle. ???.

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Systematic Experiments on Unsolved

Anomalies in 3N breakup Reactions

Kenshi Sagara ( Kyushu University)


+

g

+

+

+

3N bound state

Scattering & reactions

+


Discrepancies in 3N systems and their origins

lower energy discrepancies

Ay puzzle

1986

Ay puzzle

???

higher energy discrepancies

pd CS discrepancy

1994-1996-1997

(Sagara discrepancy)

pd sactt.

discrepancy

pp3NF(FM)

was found

1998

pr3NF?

rr3NF?

relativity?

FM-3NF

1957

pd breakup

discrepancy

3N BE problem

1980’s

pd capture

Ajj anomaly

lower energy discrepancies

Space Star anomaly

1980’s

Off-plane star anomaly

QFS anomaly?

???


+

g

+

+

+

2p3NF confirmed in BE and CS.

Complex discrepancies remain in AP’s.

Axx~Ayy, Axx anomaly

New 3NF at higher energy?

+

Discrepancies at higher energy

Discrepancies at lower energy


3H binding energy

(Theory)

(Experiment)

2NF

8.482MeV

~1MeV 2p3NF?

2p3NF has an adjustable parameter.

3H binding energy alone is not the evidence of 2p3NF.



E-dependence of Ay puzzle (1994) at KUTL

Discrepancy of

-10% ~ -40%

Ay puzzle is not related to 2p3NF.

Ay puzzle is a puzzle still now.


Energy spectrum of pd scattering at KUTL

Measurement of cross section within 1% accuracy was a hard work.


pd scattering cross section at 2-18 MeV were measured systematically

(1994)

Exp. errors < 1%.

Data were “well” reproduced by 3N calculation.

What is the output from this precise experiments?


At the cross section minimum, systematically

large discrepancy in relative value was found.

(Comapred to Approx.CoulombCalculation)

CS discrepancy is comparable to Ay puzzle.

But, no one paid attention to this fact !

I appealed this fact to Koike, but

Koike did not believe it.


At RIKEN, pd scattering was measured to construct a d-beam polarimeter.

N. Sakamoto et al., (1996)

The first contribution from SMART

pd data from SMART

Koike’s nd calculation

30% discrepancy at CS minimum

was found also at Ed = 270 MeV.

Coulomb effects are small.

Koike believe the CS discrepancy.


By Koike’s talk at Few-Body Conf. at KVI (1997), polarimeter.

CS minimum discrepancy was widely recognized.


H.Witala et al., Phys Rev Lett. 81 1183(1998) polarimeter.

Discrepancy at CS minimum was excellently explained by 2p3NF.

The same 2p3NF also reproduces 3N binding energy.

Existence of 2p3NF was confirmed (1998),

after 41 years since Fujita-Miyazawa theory (1957).


2 polarimeter. p3NF boom

from1998


+ polarimeter.

+

g

+

+

+

3NF searches started

RIKEN, KVI, RCNP, IUCF,・・

KUTL, RCNP, KVI

KUTL, RCNP


K. Sekiguchi et al. polarimeter.

Axz

Ayd

Ayy

Axx

Ed=

140MeV

Ed=

200MeV

Ed=

270MeV

Pd scattering CS is well reproduced by including 2p3NF, but

Polarization observables can not be reproduced by 2p3NF.


+ polarimeter.

+

g

+

+

+

Strategy of Kyushu group

Search for new 3NF’s other than pp3NF (pr3NF, rr3NF)

in pd capture reaction and pd breakup reaction

Kyushu G

experiments

(→new 3NF)


pd capture experiment polarimeter.

g

+

+

○Short-range forces may play important roles. (→new 3NF)

×Reaction cross section is very small (< 1 m barn).

  • Experimental techniques

  • thick target & low BG   → liquid hydrogen target

  • high-efficiency detection → one-shot measurement of whole

  • angular distribution


Side View polarimeter.

(enlargement)

Front View

f12

Liquid Hydrogen Target

精密実験に不可欠


q polarimeter. (3He) < 4.7

Vertical plane

for Axx

Horizontal plane

for Ayy & Ay

Whole angular distribution was measured in one shot.


Data analysis for Axx polarimeter.

Y



0.2 polarimeter.

0.2

0.0

0.0

Ayy

Axx

-0.2

-0.2

-0.4

-0.4

-0.6

0

50

100

150

0

50

100

150

C.M angle (deg.)

C.M angle (deg.)

0.2

0.5

0.4

0.1

0.3

Crosssection (mb/sr)

Ay

0.0

0.2

-0.1

0.1

-0.2

0.0

0

50

100

150

0

50

100

150

C.M angle (deg.)

C.M angle (deg.)

2NF

pd capture at Ed = 200 MeV

Calc. by Witala et al.

2NF+3NF

Axx anomaly? Axx~Ayy?


Ajj of pd capture were measured also at kvi and kvi data agreed with calculations
Ajj of polarimeter. pd-capture were measured also at KVI, and KVI data agreed with calculations.

Axx

Ayy

● ○RCNP(200MeV)

■ □KVI  (180MeV)

Azz


We made new experiments (present exp.) at RCNP. polarimeter.

Beam : 197 MeV (same as before)

Target : Liquid Hydrogen (same as before)

Detection: 3He (same as before)

Observables:

Axx (same as before)

Ayy (same as before)

Azz (= -Axx-Ayy) (similar to KVI)


pd radiative capture at Ed = 137 MeV polarimeter.

(multi-II analysis)


Axx polarimeter. ~Ayy in pd capture

Only Ayy measured

KVI

Ayy & Axx

measured

Axx

Ayy

RCNP

Ayy

Axx


Why Axx ~ Ayy holds in pd capture? polarimeter.

Is it a signal of new 3NF?


Nucl. Phys. A265 280(1976) polarimeter.

Nucl. Phys. A334 365(1980)

Except for pd capture, Axx~ -Ayy holds in general

  • Ed=15MeV d-3He breakup

  • d-α elastic scattering

Ayy

Ayy

Axx

Axx

Axx

Ayy


d-induced reaction in general polarimeter.

Axx ~ -Ayy

pd capture reaction

Axx ~ Ayy <0

Ayy < 0

Ayy > 0

Axx < 0

Axx < 0

Axial symmetry

Central region ?

Short-range force ?

Peripheral region ?


Discrepancies in 3N systems and their origins polarimeter.

lower energy discrepancies

Ay puzzle

1986

Ay puzzle

???

higher energy discrepancies

pd CS discrepancy

1994-1996-1997

(Sagara discrepancy)

pd sactt.

discrepancy

pp3NF(FM)

was found

1998

pr3NF?

rr3NF?

relativity?

FM-3NF

1957

pd breakup

discrepancy

3N BE problem

1980’s

pd capture

Ajj anomaly

lower energy discrepancies

Space Star anomaly

1980’s

Off-plane star anomaly

QFS anomaly?

???


pd breakup experiments polarimeter.

+

+

+

At Ep = 250 MeV to search new 3NF effects

At around Ep = 13 MeV to study Star Anomaly


Ay at 250 MeV polarimeter.

relativistic effects

3NF effects


Cross section at 250 MeV polarimeter.

K. Hatanaka et al., PRC66 044002(2002)

Y. Maeda et al., PRC76 014004(2007)

Non-relativistic

Relativistic

2NF only

2NF+3NF


Cross Section polarimeter.

Cross Section Ratio (Exp/Calc)

Cross Section at 250 MeV


Break-up polarimeter.

Elastic

At 250 MeV, BU cross section is ~5 times larger than elastic scattering cross section


First experiment polarimeter.

p1

p2

n

Only p1 detected

CS at 250 MeV

GR

Liq D2

Target

p - beam

LAS

p1


p polarimeter. 1

p2

n

CS at 250 MeV

Only p1 detected

2NF+3NF

Only 2NF

  • nd calc.by H. Witala


p polarimeter. 1

p2

n

CS at 250 MeV

Only p1 detected

2NF+3NF

Only 2NF

  • nd calc.by H. Witala


Ay at 250 MeV polarimeter.

Only p1 detected

2NF+3NF

Only 2NF

  • nd calc.by H. Witala


We first investigate discrepancy in cross section polarimeter.

p1

p2

n

Only p1 detected

CS at 250 MeV

p1 and p2 detected

detected p1

free

p2

p1


free polarimeter.

p2

p1

detected p1

C

A

B

E1

q1-dependence

at different E1

B

We selected energy B

C

A

q1


free polarimeter.

detected p1

detected p2

detected p1


q polarimeter. 2-dependence

with q1 fixed at15 degree

and F12 = 180 degree

2NF+3NF

2NF

Calc by H. Kamada

q1

F12

q1

F12-dependence

with q1 and q2 fixed

at15 degree and 35 degree

F12


q polarimeter. 2-dependence

with q1 fixed at15 degree

and F12 = 180 degree

2NF+3NF

2NF

Calc by H. Kamada

q1

F12

q1

F12-dependence

with q1 and q2 fixed

at15 degree and 35 degree

F12


p polarimeter. 1

p2

n

CS at 250 MeV

p1 and p2 detected

p2

GR

Liq D2

Target

p - beam

LAS

p1


p polarimeter. 2

p1

n

GR

VDC + DE scintillator

Momentum accept.:2.5%

  • GRとLASの相対角度の最小値は約50o

D(p,p1p2)n CS at 250 MeV

p1 and p2 detected

Liq D2

Target

Unpolarized p-beam

  • LAS

  • VDC + DE scintillator

  • Momentum accept.:2.5%

  • GRとLASの相対角度の最小値は約50o


Liquid D2 target polarimeter.





q polarimeter. 1 =15 degree and q2 =35 degree

True+BG

BG



2NF+3NF polarimeter.

Only 2NF

pp3NF effects

Calc. by H. Witala


Relativistic polarimeter.

Non-relativistic

Relativistic effects

Calc. by H. Witala


3NF effects and relativistic polarimeter. effects

Calculation by H. Witala


3NF effects and relativistic polarimeter. effects


x 5.8 polarimeter.

If pp3NF effects are artificially 5.8 times increased,

experimental CS data are roughly reproduced.


Possible enhancement of polarimeter. pp3NF at higher energy

Arbitrary unit


Summary polarimeter.

At 250 MeV, pd breakup cross section were measured by

First, detecting 1-protons from p+d p+p+n reaction,

Second, detecting 2-protons in coincidence.

Large discrepancy of about 2 times in CS was observed.

The discrepancy occurs in a wide angular region.

pp3NF effects are too small (5.8 time) to explain the discrepancy, also

relativistic effects are too small to explain the discrepancy.

CS discrepancy monotonically increases with energy.

New 3NF may be necessary to explain the discrepancy.


Discrepancies in 3N systems and their origins polarimeter.

lower energy discrepancies

Ay puzzle

1986

Ay puzzle

???

higher energy discrepancies

pd CS discrepancy

1994-1996-1997

(Sagara discrepancy)

pd sactt.

discrepancy

pp3NF(FM)

was found

1998

pr3NF?

rr3NF?

relativity?

FM-3NF

1957

pd breakup

discrepancy

3N BE problem

1980’s

pd capture

Ajj anomaly

lower energy discrepancies

Space Star anomaly

1980’s

Off-plane star anomaly

QFS anomaly?

???


The origin of space star anomaly
The origin of Space Star anomaly polarimeter.

n+d→n+n+p

Blue line:nd calcRed Line:pd calc

p+d→p+p+n

c.m. system

Space Star

nd:exp > calc

pd:exp<calc

Space Star :configurationof three outgoing nucleons form an equilateral triangle and have the same energy

calc:coulomb effect is very small


Off plane star anomaly
Off-Plane Star anomaly polarimeter.

Ed=19MeV

c.m. system

Define the angle between Star plane and beam axis, α

α=90°Space Star

Cross Section reported by Koeln Univ.

Large anomaly is shown


Off plane star anomaly1
Off-Plane Star anomaly polarimeter.

Ed=19MeV

c.m. system

Define the angle between Star plane and beam axis, α

α=90°Space Star

Cross Section reported by Koeln Univ.

Large anomaly is shown


Experiment
Experiment polarimeter.

Observable:Cross Section

Incident Energy:Ed=19MeV

Target:CH2 foil(rotary target)

Detector:Si-SSD

Set up of scattering chamber


polarimeter.

B.G.+ true

E2[MeV]

Scurve

E2[MeV]

E1[MeV]

Remove B.G.

E1[MeV]

B.G. only

T(E1)-T(E2)[ns]

E2[MeV]

T1-T2[ns]

mp :proton mass

Ei :energy of detected proton

Li :length between target and detector

E1[MeV]

Break up event


E polarimeter. d=19MeV

Present data

Koeln data

calc:Mr.Deltuva


Only Space Star Anomaly ( polarimeter. a~90º)exists.

We used an unpolarized beam to carefully measure cross section.

Why Space-Star anomaly appears is the next problem.

We will make systematic experiments at perpendicular plane.


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