Recent experiments on three nucleon systems and problems to be solved Kenshi Sagara Kyushu U., Fukuoka, Japan FB19

 Basic process High momentum transfer Various configurations QFS, FSI, Star, Collinear,.. Experiments in Nd system 3-nucleon forces 3-body effects Systematic experiments Calculatons with 2NF+3NF +

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 higher energy discrepancies -- pd sactt. discrepancy -- lower energy discrepancies -- Off-plane Sar anomaly QFS anomaly ??? Discrepancies in 3N systems and their origins FM-3NF 1957 Systematic measurements We are here. Faddeev eqs. 1960

Ay at E N =5-18 MeV (~1994) ++ Ay puzzle

nd Ay & pd Ay E N =10MeV pd Ay Ep=22.7MeV Modification factors H. Witala and W. Gloeckle, NPA528 (1991)48 NN forces 3P03P0 3P13P1 3P23P2 np pp nn A suggestion to solve Ay puzzle Modified calculations Original calculation

Ay puzzle Modification of LS force in 2NF Modification of 3PJ forces in 2NF Addition of LS force in 3NF Adjusting of forces in  PT 3NF effects? Relativistic effects? or ……….. Origin(s) Ay puzzle is a long-standing problem since 1986 (FB11).

Shortage of 3 H binding energy (1980’s) (Experiment) 8.482MeV (Theory) 2NF ~1MeV shortage 3 H B.E. can be reproduced by adjusting a parameter  in 2  3NF Another evidence was necessary to confirm 2  3NF

Systematic measurement of pd scattering cross section (1994) Here are discrepancies 18MeV 10MeV 5MeV 12MeV + +

pd cross section (RIKEN 1996) + + nd calculation by Koike 30% difference

+ + RIKEN data (1996) Kyushu data (1994) Koike’s talk at FB15 (KVI)

H.Witala et al., Phys Rev Lett (1998) 8.482MeV (exp.) 2NF 2  3NF Binding energy  3NF Fujita-Miyazawa (1957) 41 years 2p3NF was found (1998) Scattering cross section

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 higher energy discrepancies -- pd sactt. discrepancy -- lower energy discrepancies -- Off-plane Sar anomaly QFS anomaly ??? Discrepancies in 3N systems and their origins FM-3NF 1957 Systematic measurements We are here. Faddeev eqs. 1960

pd capture experiment + +  ○ high momentum transfer → short-range 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 mm

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

Y BG level was low

Axx anomaly in pd capture at E d = 200 MeV from RCNP exp. (Yagita et al. 2002) 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) RCNP data at 137MeV also disagreed with KVI data at 133MeV.

Experiment at KVI, A yy & “A zz ” (=-A xx - A yy ) Big-Bite spectrometer (BBS) & Plastic Ball detector (PB)  -detection A zz : 45±10 degree A yy : 0 ±15 dergree Azz = -Axx-Ayy Beam axis

d + p → 3 He+  Ed  eV  ( 3 He) < 4.7deg Slit in front of LAS “A zz ” = (A xx -A yy ) A xx A yy Beam polarization is along y-axis. Re-measurement at RCNP at 200 MeV

Liuqid target Empty target Background subtraction BG True y y polarized beam unpol. beam

Detection efficiency

Single cluster Multiple cluster Overlapped cluster & single cluster Overlapped–overlapped cluster Other rays ~83% ~2% ~14% ~1% Efficiency =.83 4 =0.48 Standard data analysis Efficiency =.97 4 =0.88 Efficiency =.99 4 =0.96 Multi-II data analysis X1 X2 X1 X2 Backgroun estimation was much improved by a multi-II method. Total 100% X1 X2

Single cluster data analysis vs. Multi-cluster II data analysis (new) 2002 exp.

d+p→3He+  New data and previous data (new multi-II analysis) 2002 present

d+p→3He+  New data and previous data (Multi-II) present (Axx+Ayy) “Azz”

pd radiative capture at E d = 137 MeV (multi-II analysis)

Ajj in pd capture Axx anomaly (Azz anomaly) has been confirmed. Axx ~ Ayy ---> axial symmetry ? Azz > calculation ----> short range reaction? + + 

pd scattering CS at 250 MeV E-dependence of CS at 150 degree + + exp/cal at  = 150 ⁰ 2  3NF  =150 ⁰

J. Kuros-Zoluierczuk et al., PRC66, (2002).

D(p,pp)n CS at 250 MeV + ++

d p p detected un-detected d p p detected p Inclusive exp. at 250 MeV D(p,p)pn experiment (global feature) Exclusive exp. at 250 MeV D(p,pp)n experiment (microscopic study) --> Kuroita’s talk + ++

pd breakup CS at 250 MeV, inclusive & exclusive Large (~2 times) CS enhancement pd & nd scattering CS above 150 MeV Short-range 3NF? Relativity? ……..?

+ ++ Space star anomaly around 10 MeV

α=144º α=124º

～ QFS EnEn Is there QFS anomaly in addition to space star anomaly? + ++ QFS anomaly?

Result (pp-QFS) QFS E p = 9.5 MeV E p = 13 MeV QFS ~7% smaller ~9% smaller star

pd QFS E p = 9.5 MeV E p = 13 MeV

A. Siepe et al., Phys. Rev. C 65, (2002) ～ 18% θ 1 = θ 2 = 42 deg. θ 1 = θ 2 = 42.2 deg. ～ 16% X. C. Ruan et al., Phys. Rev. C 75, (2007) nd QFS pd QFS Also there are nd QFS (2002,2007), and CS of nd QFS is higher than calculation, CS of pd QFS is lower than calculation

① ② ③ ④ ⑤ ⑥ ⑦ E p = 9.5 MeV E p = 13 MeV Angular dependence of QFS anomaly

Nd breakup cross section at low energy Star anomaly appears only around space star (  = 90 °) at 13 MeV, and in a wide angular region at 9.5MeV. Large CSB occurs, nd CS> calc, and pd CS < calc. Star anomaly 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 CS> calc, and pd CS < calc. What origin(s) Same origin or different ones?

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 higher energy discrepancies -- pd sactt. discrepancy -- lower energy discrepancies -- Off-plane Sar anomaly QFS anomaly ??? Discrepancies in 3N systems and their origins FM-3NF 1957 Systematic measurements We are here. Faddeev eqs. 1960

More systematic experiments on some reactions More challenging calculations with new 3NF, new frame, … remaining 3NF’s unknown 3-body effects ……. +