Systematic Experiments on Unsolved Anomalies in 3N breakup Reactions Kenshi Sagara ( Kyushu University)

 3N bound state Scattering & reactions

Ay puzzle 1986 Ay puzzle pd CS discrepancy (Sagara discrepancy) 3N BE problem 1980’s  3NF(FM) was found 1998 pd breakup discrepancy pd capture Ajj anomaly  3NF?  3NF? relativity? Space Star anomaly 1980’s higher energy discrepancies pd sactt. discrepancy lower energy discrepancies Off-plane star anomaly QFS anomaly? ??? Discrepancies in 3N systems and their origins FM-3NF 1957

 2  3NF 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

3 H binding energy (Experiment) 8.482MeV (Theory) 2NF ~1MeV 2  3NF? 2  3NF has an adjustable parameter. 3 H binding energy alone is not the evidence of 2  3NF.

Systematic measurement of pd scattering Ay at Ep =2-18 MeV at KUTL (1994)

E-dependence of Ay puzzle (1994) Ay puzzle is not related to 2  3NF. Ay puzzle is a puzzle still now. Discrepancy of -10% ~ -40%

Measurement of cross section within 1% accuracy was a hard work. Energy spectrum of pd scattering

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, 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. 30% discrepancy at CS minimum was found also at Ed = 270 MeV. Coulomb effects are small. Koike believe the CS discrepancy. pd data from SMART Koike’s nd calculation N. Sakamoto et al., (1996) The first contribution from SMART

By Koike’s talk at Few-Body Conf. at KVI (1997), CS minimum discrepancy was widely recognized.

H.Witala et al., Phys Rev Lett (1998) Discrepancy at CS minimum was excellently explained by 2  3NF. The same 2  3NF also reproduces 3N binding energy. Existence of 2  3NF was confirmed (1998), after 41 years since Fujita-Miyazawa theory (1957).

2  3NF boom from1998

 3NF searches started RIKEN, KVI, RCNP, IUCF, ・・ KUTL, RCNP, KVI KUTL, RCNP

Ed= 140MeV Ed= 200MeV Ed= 270MeV AydAyd A xz A yy A xx K. Sekiguchi et al. Pd scattering CS is well reproduced by including 2  3NF, but Polarization observables can not be reproduced by 2  3NF.

Strategy of Kyushu group Search for new 3NF’s other than  3NF (  3NF,  3NF) in pd capture reaction and pd breakup reaction  Kyushu G experiments (→new 3NF)

pd capture experiment + +  ○ Short-range forces may play important roles. (→new 3NF) × Reaction cross section is very small (< 1  barn). Experimental techniques thick target & low BG → liquid hydrogen target high-efficiency detection → one-shot measurement of whole angular distribution

Liquid Hydrogen Target 精密実験に不可欠

Vertical plane for Axx Horizontal plane for Ayy & Ay  ( 3 He) < 4.7  Whole angular distribution was measured in one shot.

Y Data analysis for Axx

Data analysis for Ayy & Ay 

pd capture at E d = 200 MeV ２ NF ２ NF ＋３ NF Calc. by Witala et al  0.2  0.4  0.6 A xx C.M angle (deg.)  0.2  0.4 A yy C.M angle (deg.)  0.1  0.2 AyAy C.M angle (deg.) Cross section (mb/sr) 0.0 C.M angle (deg.) Axx anomaly? Axx~Ayy?

Ajj of pd-capture were measured also at KVI, and KVI data agreed with calculations. A xx A yy A zz ● ○ RCNP(200MeV) ■ □ KVI （ 180MeV)

We made new experiments (present exp.) at RCNP. 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 (multi-II analysis)

Axx ~ Ayy in pd capture KVI RCNP A ｘｘ AｙｙAｙｙ AｙｙAｙｙ Axx Ayy & Axx measured Only Ayy measured

Why Axx ~ Ayy holds in pd capture? Is it a signal of new 3NF?

 d-α elastic scattering  Ed=15MeV d- 3 He breakup Nucl. Phys. A (1976) Nucl. Phys. A (1980) Except for pd capture, Axx~ -Ayy holds in general A yy A xx A yy

A yy < 0 A xx < 0 pd capture reaction Axx ~ Ayy <0 A yy > 0 A xx < 0 d-induced reaction in general Axx ~ -Ayy Peripheral region ? Axial symmetry Central region ? Short-range force ?

Ay puzzle 1986 Ay puzzle pd CS discrepancy (Sagara discrepancy) 3N BE problem 1980’s  3NF(FM) was found 1998 pd breakup discrepancy pd capture Ajj anomaly  3NF?  3NF? relativity? Space Star anomaly 1980’s higher energy discrepancies pd sactt. discrepancy lower energy discrepancies Off-plane star anomaly QFS anomaly? ??? Discrepancies in 3N systems and their origins FM-3NF 1957

+ ++ pd breakup experiments At Ep = 250 MeV to search new 3NF effects At around Ep = 13 MeV to study Star Anomaly

Ay at 250 MeV 3NF effects relativistic effects

2NF only 2NF+3NF Non-relativistic Relativistic K. Hatanaka et al., PRC (2002) Y. Maeda et al., PRC (2007) Cross section at 250 MeV

Cross Section Cross Section at 250 MeV Cross Section Ratio (Exp/Calc)

Elastic Break-up At 250 MeV, BU cross section is ~5 times larger than elastic scattering cross section

GR LAS p - beam Liq D 2 Target CS at 250 MeV Only p 1 detected p1p1 p2p2 n p1p1 First experiment

CS at 250 MeV Only p 1 detected 2NF+3NF Only 2NF nd calc.by H. Witala p2p2 n p1p1

CS at 250 MeV Only p 1 detected 2NF+3NF Only 2NF nd calc.by H. Witala p2p2 n p1p1

2NF+3NF Only 2NF nd calc.by H. Witala Ay at 250 MeV Only p 1 detected

detected p 1 free We first investigate discrepancy in cross section CS at 250 MeV Only p 1 detected p2p2 n p1p1 p 1 and p 2 detected p2p2 p1p1

A B C A C B  1 -dependence at different E 1 11 E1E1 detected p 1 free p2p2 p1p1 We selected energy B

detected p 1 free detected p 1 detected p 2

2NF+3NF 2NF Calc by H. Kamada  2 -dependence with  1 fixed at15 degree and  12 = 180 degree  12 -dependence with  1 and  2 fixed at15 degree and 35 degree  12 11 11

2NF+3NF 2NF Calc by H. Kamada  2 -dependence with  1 fixed at15 degree and  12 = 180 degree  12 -dependence with  1 and  2 fixed at15 degree and 35 degree  12 11 11

GR LAS p - beam Liq D 2 Target p1p1 p2p2 CS at 250 MeV p2p2 n p1p1 p 1 and p 2 detected

GR VDC +  E scintillator Momentum accept. ： 2.5% GR と LAS の相対角度 の最小値は 約 50 o Unpolarized p-beam Liq D 2 Target D(p,p 1 p 2 )n CS at 250 MeV p 1 and p 2 detected LAS VDC +  E scintillator Momentum accept. ： 2.5% GR と LAS の相対角度 の最小値は 約 50 o p2p2 n p1p1

Liquid D2 target

Previous data were confirmed. New data were added. 3NF effects

Same data. Relativistic effects.

Same data. 3NF effects and relativistic effects.

True+BG BG  1 =15 degree and  2 =35 degree

Check of the absolute cross section

Calc. by H. Witala  3NF effects 2NF+3NF Only 2NF

Calc. by H. Witala Relativistic effects Relativistic Non-relativistic

Calculation by H. Witala 3NF effects and relativistic effects

x 5.8 If  3NF effects are artificially 5.8 times increased, experimental CS data are roughly reproduced.

Arbitrary unit Possible enhancement of  3NF at higher energy

Summary 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.  3NF 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.

Ay puzzle 1986 Ay puzzle pd CS discrepancy (Sagara discrepancy) 3N BE problem 1980’s  3NF(FM) was found 1998 pd breakup discrepancy pd capture Ajj anomaly  3NF?  3NF? relativity? Space Star anomaly 1980’s higher energy discrepancies pd sactt. discrepancy lower energy discrepancies Off-plane star anomaly QFS anomaly? ??? Discrepancies in 3N systems and their origins FM-3NF 1957

The origin of Space Star anomaly Space Star ： configuration of three outgoing nucleons form an equilateral triangle and have the same energy Blue line ： nd calc Red Line ： pd calc Space Star nd : exp > calc ｐ d : exp ＜ calc calc ： coulomb effect is very small c.m. system n+d→n+n+p p+d→p+p+n

Off-Plane Star anomaly Cross Section reported by Koeln Univ. Define the angle between Star plane and beam axis, α α=90° Space Star Large anomaly is shown c.m. system E d =19Me V

Off-Plane Star anomaly Cross Section reported by Koeln Univ. Define the angle between Star plane and beam axis, α α=90° Space Star Large anomaly is shown c.m. system E d =19Me V

Experiment Observable ： Cross Section Incident Energy ：Ｅ ｄ = １９ MeV Target ： CH 2 foil （ rotary target ） Detector ： Si-SSD Set up of scattering chamber １２

T 1 -T 2 [ns] T(E 1 )-T(E 2 )[ns] Break up event Ｅ １ [MeV] Ｅ 2 [MeV] Ｓ curve m p : proton mass E i : energy of detected proton L i : length between target and detector Remove B.G. Ｅ 2 [MeV] Ｅ １ [MeV] B.G.+ true Ｅ 2 [MeV] Ｅ １ [MeV] B.G. only １２

E d =19MeV calc ： Mr.Deltuva Present data Koeln data

Only Space Star Anomaly (  ~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.