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A large set of cross-section data for the H-1 (d,pp)n breakup reaction was measured at 130 MeV deuteron beam energy with the Germanium Wall setup covering the range of very forward polar angles. In the investigated part of the phase-space, the dynamics is dominated by the Coulomb force influence. The data are compared with results of theoretical calculations based on the realistic Argonne V18 potential supplemented with the long-range electromagnetic component. The predictions also include the Urbana IX three nucleon force model. The cross-section data reveal seizable Coulomb force effects.

We have measured a complete set of deuteron analyzing powers in deuteron–proton elastic scattering at 190, 250, and 294 MeV/nucleon. The obtained data are compared with the Faddeev calculations based on the modern nucleon–nucleon forces together with the Tucson-Melbourne’99, and UrbanaIX three nucleon forces. The data are also presented with the calculations based on the N4LO NN potentials of the chiral effective field theory.

Precise and large sets of cross section, vector $A_{x}, A_{y}$ and tensor$ A_{xx}, A_{xy}, A_{yy}$ analyzing power data for the $^{1}H\left ( d, pp \right )n$ breakup reactions were measured at 100 and 130 MeV deuteron beam energies with the SALAD and BINA detectors at KVI and the Germanium Wall setup at FZ-Jülich. Results are compared with various theoretical approaches which model the three-nucleon system dynamics. The cross section data reveal a sizable three-nucleon force (3NF) and Coulomb force influence. In case of the analyzing powers very low sensitivity to these effects was found and the data are well describe by 2N models only. For $A_{xy}$ at 130 MeV, serious disagreements were observed when 3NF models are included in the calculations.

Low-pressure multi-wire drift chambers have been developed to track high-intensity radioactive isotope beams at the energies of around 200 MeV/nucleon. In order to minimize the effect of multiple scattering by radioactive isotope beam, the thickness of the detectors were minimized by using isobutane gas at low pressure (10 kPa). The performance of the position resolution, the tracking efficiency, and the beam intensity capability were evaluated as a function of atomic number and applied voltage. As a result, an overall position resolution of 300 μm was achieved for radioactive isotope beams with an intensity of 1 MHz. The details of the design specifications and performances of the low-pressure multi-wire drift chambers are described.

We have measured all deuteron analyzing powers \({(A_{y}^{d}, A_{yy}, A_{xx}, A_{xz})}\) for deuteron-proton elastic scattering at 294 MeV/nucleon in order to study the properties of three nucleon forces (3 NFs). Measurement was made at in an angular range of \({\theta_{{\rm c.m.}} = 35.6^{\circ} - 163.0^{\circ}}\). Obtained data were compared with Faddeev calculations with and without the 3 NFs. At \({\theta_{{\rm c.m.}}\lesssim 120^{\circ}}\) all the data have general agreement with the calculations, while the measured data at \({\theta_{{\rm c.m.}} \gtrsim 120^{\circ}}\) are not explained by any theoretical calculations. These results were consistent with those at 250 MeV/nucleon.

With the aim of clarifying roles of the 3NFs in nuclei experimental programs with the polarized deuteron beam at intermediate energies are in progress at RIKEN RI Beam Factory. As the first step, we have measured a complete set of deuteron analyzing powers in deuteron–proton elastic scattering at 250 and 294 MeV/nucleon. The obtained data are compared with the Faddeev calculations based on the modern nucleon–nucleon forces together with the Tucson–Melbourne’99, and UrbanaIX three nucleon forces.

The review of the recent results on spin effects in few nucleon systems obtained at LHEP-JINR are presented. The data on the deuteron analyzing powers in different reactions in the wide energy range demonstrate the sensitivity to the spin structure of the light nuclei. The future plans on the studies with polarized deuterons from new polarized ion source at Nuclotron will be reported.

Recent results on the spin effects in deuteron inclusive breakup and deuteron-proton elastic scattering obtained at the Veksler and Baldin Laboratory of High Energies at JINR are reported. The experimental data have been obtained with the use of a high-energy polarized deuteron beam at the Synchrophasotron-Nuclotron Accelerator Complex. The covered energy range corresponds to the short internucleonic distances where the relativistic effects and non-nucleonic degrees of freedom can play a significant role.

The data on the vector A y and tensor A yy , A xx , A xz analyzing powers for the $$ \vec d $$ d → 3H p reaction have been obtained at the energy of the initial deuteron of 200MeV in the angular range of 0–95 degrees in the c.m.s. The calculations performed within one-nucleon exchange model with the use of the standard three-nucleon bound state wave functions fail to reproduce the data on the tensor analyzing powers.

Recent experimental progress of the three-nucleon force study is shown placing an emphasis on the nucleon-deuteron elastic scattering at intermediate energies.

Recent experimental progress of the three-nucleon force study using the nucleon-deuteron system at intermediate energies is reviewed with personal taste.

Measurements of deuteron–proton breakup reactions at 135 MeV/A have been made at RIKEN Accelerator Research Facility, focusing on the specific coplanar configurations. The obtained results are compared with the Faddeev calculations based on the modern nucleon–nucleon forces together with the Tucson-Melbourne99, and UrbanaIX three nucleon forces.

The cross sections and spin observables of the pd elastic scattering have been measured at 392 MeV. The results are compared with the prediction of Faddeev calculations with and without including a three nucleon force.

The differential cross sections and the vector analyzing powers for the nd elastic scattering at E n = 250 MeV have been measured for the study of the three-nucleon force (3NF) effects in the Coulomb-free system. To cover a wide angular region, the experiments were performed by using two different methods at the ( n , p ) facility and at the NTOF facility which constructed at the Research Center for Nuclear Physics (RCNP). The results were compared with theoretical predictions of the Faddeev calculations based on the modern nucleon-nucleon (NN) forces with the three-nucleon force (3NF). The inclusion of 3NFs leads to a good description of the cross section except for the backward angles. The results were also compared with the theoretical predictions with relativistic corrections. The direct data-to-data comparison of the cross sections of the nd and pd was performed.

Extensive studies of three-nucleon force (3NF) effects in elastic proton-deuteron scattering have been performed at KVI and elsewhere in the past. In the present work, we explored 3NF effects in the break-up scattering process by performing high precision measurement of vector analyzing powers and differential cross sections using a 190 MeV polarized-proton beam on a liquid deuterium target. The experiment was performed by exploiting a new detector called Big Instrument for Nuclear-polarization Analysis, BINA. Its unique design enables coverage of almost the complete reaction phase space. Preliminary differential cross sections and vector analyzing powers are presented and results are compared with state-of-the-art three-nucleon calculations.

With the aim of clarifying roles of the 3NFs in nuclei experimental programs with the polarized deuteron beam at intermediate energies are in progress at RIKEN RI Beam Factory. As the first step, we have measured a complete set of deuteron analyzing powers in deuteron–proton elastic scattering at 250 and 294 MeV/nucleon. The obtained data are compared with the Faddeev calculations based on the modern nucleon–nucleon forces together with the Tucson–Melbourne’99, and UrbanaIX three nucleon forces.

A new high-energy beam polarimeter is proposed for Nuclotron, which uses the Internal Target Station (ITS). This polarimeter based on a measurement of asymmetry for the d–p elastic scattering will allow one to measure simultaneously both vector and tensor components of deuteron beam polarization. For this purpose an analyzing powers measurement for the d–p elastic scattering at energies T d = 0.88–2 GeV is proposed. The precise measurements of the deuteron analyzing powers over the energy range T d = 300–2000 MeV can give an irreplaceable clue to the study of the spin dependence of three nucleon forces.

Several examples of recent experimental activities in Japan on the study of three-nucleon-force (3NF) effect via the nucleon-deuteron (Nd) elastic scattering at intermediate energies are reviewed. Discrepancies between the data and theoretical predictions are identified.

We have measured angular distributions of the differential cross-section, the analyzing power and all of the spin transfer coefficients K y y′ , K x x′ , K z x′ , K x z′ , and K z z′ for the pd elastic scattering at 250 MeV. These are the first measurements of a complete set of proton polarization observables for pd elastic scattering at intermediate energies. The present data are compared with theoretical predictions based on exact solutions of the three-nucleon Faddeev equations and modern realistic nucleon-nucleon potentials combined with three-nucleon forces (3NF), namely the Tucson-Melbourne (TM) 2π-exchange model, a modification thereof (TM′) closer to chiral symmetry, and the Urbana IX model.

Several examples of recent experimental activities in Japan on the study of three-nucleon-force effects via the Nd elastic scattering at intermediate energies are briefly reviewed. Differences between the data and theoretical predictions are identified.

Measurements of the tensor and vector analyzing powers Ayy, Axx, Axz, and Ay for the [Formula: see text] and [Formula: see text] reactions were performed at Ed = 270 and 200 MeV over wide angular range. T20 at θ cm = 0° and 180° were also measured at Ed = 270, 200, and 140 MeV. Obtained data were compared with predictions based on one nucleon exchange approximation.

The cross sections and spin observables of the p+d elastic scattering have been measured at 392 MeV. The results are compared with the results of Faddeev calculations with and without including the three nucleon force.

The angular distributions of the cross section, the proton analyzing power and all of proton polarization transfer coefficients of [Formula: see text] elastic scattering were measured at 250 MeV. The present data are compared with theoretical predictions based on exact solutions of the three-nucleon Faddeev equations and modern realistic nucleon-nucleon potentials combined with three-nucleon forces. These results call for a better understanding of the spin structure of the three-nucleon force and very likely for a full relativistic treatment of the three-nucleon continuum.

The results on the vector Ay and tensor Ayy, Axx and Axz analyzing powers of the \(\vec dd \to {}^3Hen\) and \(\vec dd \to {}^3Hp\) reactions obtained at intermediate energies at RARF(RIKEN, Japan) are presented. The high precision experimental data are compared with the theoretical calculation within the one nucleon exchange model by using standard 3He, 3H and deuteron wave functions. The data demonstrate the sensitivity to the short-range 3He, 3H and deuteron spin structure.

New polarimeter based on the asymmetry measurement in dp-elastic scattering has been constructed at internal target at Nuclotron (JINR). The result on the deuteron analyzing powers Ay, Ayy and Axx in the deuteron-proton (dp) elastic scattering at the energies of 880 and 2000 MeV are presented. They are compared with different theoretical approaches.

Rich sets of high precision cross sections, vector and tensor analyzing powers for the [Formula: see text] breakup reaction were measured at 130 and 100 MeV beam energy with the use of detection systems covering large parts of the phase space. The cross section data allowed to establish evidences for three-nucleon force contributions and to confirm predictions of sizable effect of the Coulomb force in the breakup reaction. Analyzing power data are generally quite well described by theoretical predictions even with pure nucleon-nucleon interactions. However, in some regions discrepancies has been observed for tensor analyzing powers at 130 MeV.

One of the most important goals of modern nuclear physics is to contruct nuclear force model which properly describes the experimental data. To develop and test predictions of current models the breakup $^{1}H\left ( \vec{d}, pp \right )n$ reaction was investigated experimentally at 100 and 130 MeV deuteron beam energies. Rich set of data for cross section, vector and tensor analyzing powers was obtained with the use of the SALAD and BINA detectors at KVI and Germanium Wall setup at FZ-Jülich. Results are compared with various theoretical approaches which describe the three-nucleon (3N) system dynamics. For correct description of the cross section data both, three-nucleon force (3NF) and Coulomb force, have to be included into calculations and influence of those ingredients is seizable at specific parts of the phase space. In case of the vector analyzing powers very low sensitivity to any effects beyond nucleon-nucleon interaction was found. At 130 MeV, the $A_{xy}$ data are not correctly described when 3NF models are included into calculations.

A complete high-precision set of deuteron analyzing powers for elastic deuteron-proton (dp) scattering at 250 and 294 MeV/nucleon has been measured. These data and previously existing data sets for the cross section at similar energies are compared to the results of three-nucleon Faddeev calculations based on modern nucleon-nucleon (NN) potentials alone or combined with two models of three-nucleon forces: the Tucson-Melbourne 99 and Urbana IX. Large discrepancies between pure NN theory and data, which are not resolved by the current three-nucleon forces, were found at c.m. backward angles θc.m.≳120∘ for all the deuteron analyzing powers and the cross section. Because only small relativistic effects were found for the deuteron analyzing powers and the cross section, the inclusion of short-range components of the three-nucleon force is probably required to get a better description of the data.

The cross section, the deuteron vector ${A}_{y}^{d}$ and tensor analyzing powers ${A}_{\mathrm{ij}}$, the polarization transfer coefficients ${K}_{\mathrm{ij}}^{{y}^{\ensuremath{'}}}$, and the induced polarization ${P}^{{y}^{\ensuremath{'}}}$ were measured for the $\mathrm{dp}$ elastic scattering at 270 MeV. The cross section and ${A}_{y}^{d}$ are well reproduced by Faddeev calculations with modern data-equivalent nucleon-nucleon forces plus the Tucson-Melbourne three-nucleon force. In contrast, ${A}_{\mathrm{ij}}$, ${K}_{\mathrm{ij}}^{{y}^{\ensuremath{'}}}$, or ${P}^{{y}^{\ensuremath{'}}}$ are not described by such calculations. These facts indicate the deficiencies in the spin dependence of the Tucson-Melbourne force and call for extended three-nucleon force models.

New vector analyzing-power data on (p) over right arrow+ d elastic scattering at E-p = 150 and 190 MeV have been measured. These an presented together with existing data and with recent (d) over right arrow + p vector and tensor analyzing power data at E-d = 270 MeV. The strong negative extremum of both vector analyzing powers A(y)(p) and A(y)(d) at theta(c.m.) similar or equal to 80 degrees-120 degrees is underestimated by Faddeev calculations using modern NN forces. Inclusion of the Tucson-Melbourne 3N force shifts the minima upwards, but with conflicting results for p A(y)(p), and leading to a good description for A(y)(d). An A(y)(p) puzzle, previously thought to exist at energies E-N less than or equal to 30 MeV only, appears to exist also at intermediate energies.

Differential cross sections at θlab = 0.0°–12.3° and a complete set of polarization transfer observables at θlab = 0.0° are measured for the 90Zr(p, n) reaction at Tp = 295 MeV. A multipole decomposition (MD) technique is applied to the cross sections to extract partial cross sections σL with L=0, 1, 2, and 3 contributions. A significant amount of σL=0 is found in the highly excited continuum region. After subtracting the estimated iso-vector spin-monopole strength from σL=0, the Gamow-Teller (GT) strength B(GT) is deduced to be Sβ− = Σ B(GT) = 28 ± 1.6 ± 5.4. The total spin transfer Σ(0°) which is independent of the nuclear reaction mechanisms such as the effective nucleon-nucleon interaction or distortions is derived from the complete set of polarization transfer observables. It is close to unity up to 50 MeV excitation indicating the strong spin-flip character of the continuum. By using the relation between the polarization transfer observables the fractions of natural-parity and unnatural-parity transitions are also obtained and the dominance of unnatural-parity transitions in the continuum is found. These results are consistent with those derived from the MD analysis. The Sβ− − Sβ+ value is 27.1 and this is 90% of Ikeda's sum rule value of 3(N - Z)=30. Consequently it is concluded that the quenching of the GT strength is small and the quenching mechanism due to the ΔN− admixture seems to play a minor role.

Precise and large set of cross sections, vector A ( )x( ), A ( )y( ) and tensor A ( )xx( ), A ( )xy( ), A ( )yy( ) analyzing powers for the (1) H(d, pp)n breakup reactions were measured at 100 and 130 MeV deuteron beam energies with the use of the SALAD and BINA detectors at KVI and Germanium Wall setup at FZ-Jülich. Results are compared with various theoretical approaches which model the three-nucleon (3N) system dynamics. The calculations are based on different two-nucleon (2N) potentials which can be combined with models of the three-nucleon force (3NF) and other pieces of the dynamics can also be included like the Coulomb interaction and relativistic effects. The cross sections data reveal seizable 3NF and Coulomb force influence. In case of analyzing powers very low sensitivity to the effects was found and the data are well describe by 2N models only. At 130 MeV for A ( )xy( ) serious disagreements appear when 3NF models are included into calculations.

Vector analyzing powers for proton elastic scattering from 8He at 71 MeV/nucleon have been measured using a solid polarized proton target operated in a low magnetic field of 0.1 T. The spin-orbit potential obtained from a phenomenological optical model analysis is found to be significantly shallower and more diffuse than the global systematics of stable nuclei, which is an indication that the spin-orbit potential is modified for scattering involving neutron-rich nuclei. A close similarity between the matter radius and the root-mean-square radius of the spin-orbit potential is also identified., Comment: 6 pages, 4 figures, accepted for publication in Physical Review C Rapid Communication

Recent results on spin effects in few nucleon systems obtained at Nuclotron-JINR are presented. The data on the deuteron analyzing powers in different reactions in the wide energy range demonstrate the sensitivity to the short-range spin structure of the light nuclei. The future plans on the studies with polarized deuterons from new polarized ion source at Nuclotron will be reported.

A complete set of deuteron analyzing powers for elastic deuteron-proton([Formula: see text]) scattering at 250 and 294 MeV/nucleon has been measured. The obtained data are compared with the Faddeev calculations based on the modern nucleon-nucleon forces together with three-nucleon forces.

Precise measurements of the deuteron to proton polarization transfer coefficients for the d-p elastic scattering have been made at 135 MeV/u at RIKEN Accelerator Research Facility. The obtained results are compared with the Faddeev calculations based on modern nucleon-nucleon forces together with Tucson-Melbourne Tucson-Melbourne' and Urbana–Argonne type of three nucleon forces.

The vector analyzing power has been measured for the elastic scattering of neutron-rich 6He from polarized protons at 71 MeV/nucleon making use of a newly constructed solid polarized proton target operated in a low magnetic field and at high temperature. Two approaches based on local one-body potentials were applied to investigate the spin-orbit interaction between a proton and a 6He nucleus. An optical model analysis revealed that the spin-orbit potential for 6He is characterized by a shallow and long-ranged shape compared with the global systematics of stable nuclei. A semimicroscopic analysis with a alpha+n+n cluster folding model suggests that the interaction between a proton and the alpha core is essentially important in describing the p+6He elastic scattering. The data are also compared with fully microscopic analyses using non-local optical potentials based on nucleon-nucleon g-matrices., 20 pages, 20 figures, accepted by Physical Review C

A complete high precision set of deuteron analyzing powers for elastic deuteron-proton ($dp$) scattering at 250 MeV/nucleon (MeV/N) has been measured. The new data are presented together with data from previous measurements at 70, 100, 135 and 200 MeV/N. They are compared with the results of three-nucleon (3N) Faddeev calculations based on modern nucleon-nucleon (NN) potentials alone or combined with two models of three nucleon forces (3NFs): the Tucson-Melbourne 99 (TM99) and Urbana IX. At 250 MeV/N large discrepancies between pure NN models and data, which are not resolved by including 3NFs, were found at c.m.\ backward angles of $\theta_{\rm c.m.}\gtrsim 120^\circ$ for almost all the deuteron analyzing powers. These discrepancies are quite similar to those found for the cross section at the same energy. We found small relativistic effects that cannot resolve the discrepancies with the data indicating that other, short-ranged 3NFs are required to obtain a proper description of the data., Comment: submitted to Phys. Rev. C

The proportionality between differential cross sections at vanishing linear momentum transfer and Gamow-Teller transition strength, expressed in terms of the unit cross section (${\mathrm{\ensuremath{\sigma}\ifmmode \hat{}\else \^{}\fi{}}}_{\mathit{GT}}$), was studied as a function of target mass number for ($t$,$^{3}\mathrm{He}$) and ($^{3}\mathrm{He}$,$t$) reactions at $115A$ MeV and $140A$ MeV, respectively. Existing ($^{3}\mathrm{He}$,$t$) and ($t$,$^{3}\mathrm{He}$) data on targets with mass number $12\ensuremath{\leqslant}A\ensuremath{\leqslant}120$ were complemented with new and reevaluated ($t$,$^{3}\mathrm{He}$) data on proton, deuteron, $^{6}\mathrm{Li}$, and $^{12}\mathrm{C}$ targets. It was found that in spite of the small difference in beam energies between the two probes, the unit cross sections have a nearly identical and simple dependence on target mass number $A$, for $A\ensuremath{\geqslant}12$: ${\mathrm{\ensuremath{\sigma}\ifmmode \hat{}\else \^{}\fi{}}}_{\mathit{GT}}=109/{A}^{0.65}$. The factorization of the unit cross sections in terms of a kinematical factor, a distortion factor, and the strength of the effective spin-isospin transfer nucleus-nucleus interaction was investigated. Simple phenomenological functions depending on mass number $A$ were extracted for the latter two. By comparison with plane and distorted-wave Born approximation calculations, it was found that the use of a short-range approximation for knock-on exchange contributions to the transition amplitude results in overestimated cross sections for reactions involving the composite ($^{3}\mathrm{He}$,$t$) and ($t$,$^{3}\mathrm{He}$) probes.

Vector analyzing power for the proton-{sup 6}He elastic scattering at 71 MeV/nucleon has been measured for the first time, with a newly developed polarized proton solid target, which works at a low magnetic field of 0.09 T. The results are found to be incompatible with a t-matrix folding model prediction. Comparisons of the data with g-matrix folding analyses clearly show that the vector analyzing power is sensitive to the nuclear structure model used in the reaction analysis. The {alpha}-core distribution in {sup 6}He is suggested to be a possible key for understanding the nuclear structure sensitivity.

The high-resolution SHARAQ spectrometer and the dedicated beam-line have been constructed at the RI beam factory. Cathode-readout drift chambers placed at the focal plane of SHARAQ and multi-wire drift chambers in the beam-line worked satisfactorily for heavy ion beams with Z = 1?7 at 200?250 MeV/nucleon. By introducing a dispersion matched operation of the beam-line, we have achieved a momentum resolution of ?p/p = 1/8100 for a primary beam of 14N beam with a momentum spread of ?0.1%.

Precision data are presented for the break-up reaction, $^2{\rm H}(\vec p,pp)n$, within the framework of nuclear-force studies. The experiment was carried out at KVI using a polarized-proton beam of 190 MeV impinging on a liquid-deuterium target and by exploiting the detector, BINA. Some of the vector-analyzing powers are presented and compared with state-of-the-art Faddeev calculations including three-nucleon forces effect. Significant discrepancies between the data and theoretical predictions were observed for kinematical configurations which correspond to the $^2{\rm H}(\vec p,^2$He$)n$ channel. These results are compared to the $^2{\rm H}(\vec p,d)p$ reaction to test the isospin sensitivity of the present three-nucleon force models. The current modeling of two and three-nucleon forces is not sufficient to describe consistently polarization data for both isospin states., 4 pages, 3 figures, submitted to PRL

The deuteron to proton polarization transfer coefficients ${K}_{\mathit{yy}}^{{y}^{'}}$ and ${K}_{y}^{{y}^{'}}$ together with the deuteron analyzing powers are measured in three coplanar configurations of the deuteron-proton breakup reaction with a 135-MeV/nucleon polarized deuteron beam at the RIKEN Accelerator Research Facility. The data are compared with theoretical predictions based on exact solutions of the three-nucleon ($3N$) Faddeev equations with high-precision nucleon-nucleon ($\mathit{NN}$) forces, alone or combined with two $3N$ force (3NF) models, the $2\ensuremath{\pi}$-exchange Tucson-Melbourne${}^{'}(99)$ (${\mathrm{TM}}^{'}99$) and Urbana IX. Large 3NF effects have been found for all the measured observables. Predicted effects are supported by the data, with the exception of the vector analyzing power ${A}_{y}^{d}$. For this observable, theory based on only $\mathit{NN}$ forces is sufficient to explain the data. The behavior of the breakup analyzing powers is found to be different from the corresponding observables in elastic nucleon-deuteron scattering.

We have measured for the first time yields of both neutron‐proton and neutron‐neutron pairs emitted from the non‐mesonic weak decay of the Λ5He and Λ12C hypernuclei, produced via the (π+,K+) reaction. From the yields of both the back‐to‐back np‐pair events and nn‐pair events, we have directly determined the ratio of the neutron‐ and proton‐induced decay widths, Γn(Λn→nn)/Γp(Λp→np). Meanwhile, we have also determined the quenching of the observed numbers of single nucleons and coincident nucleon pairs compared with theoretical calculations. Our results suggest that contributions from the two‐nucleon‐induced three‐body process ΛNN→NNN are significant.

A discussion is presented of the dynamics underlying three-body nuclear forces, with emphasis on changes which occurred over several decades., Comment: Talk given at the FM50 symposium, Tokyo, October 2007