K. Sekiguchi - Academia.edu (original) (raw)
Papers by K. Sekiguchi
AIP Conference Proceedings, 2002
Precise data on cross sections, analyzing powers and polarization transfer coefficients are measu... more Precise data on cross sections, analyzing powers and polarization transfer coefficients are measured for the dp elastic scattering at 270 MeV (135 MeV/nucleon) and compared to Faddeev calculations assuming the nd scattering with modern nucleon-nucleon (NN) forces including the 2pi exchange Tucson-Melbourne (TM) three-nucleon (3N) force. Excellent fits are obtained for the cross sections and vector analyzing powers when the 3N force is included, while the fits are deteriorated for the tensor analyzing powers if the 3N force is included. A moderate fit is obtained for the polarization transfer coefficients. Based on theses results, one can conclude that the size of amplitudes of the TM-3N force may be adequate but the spin dependent part may be deficient. The cross sections and the vector analyzing powers for the nd elastic scattering at 250 MeV are measured for the first time. Backward cross sections are underestimated by the NN+3N force Faddeev calculations. This difference might be attributed to relativistic effects. .
A New Era of Nuclear Structure Physics, 2004
Precise data on the cross section and analyzing powers were measured for the d-p elastic scatteri... more Precise data on the cross section and analyzing powers were measured for the d-p elastic scattering at 70, 100 and 135 MeV/u. Also deuteron to proton polarization transfer coefficients Kyy' , Kxzy' , Kyyy' , Kxxy' were measured at 135 MeV/u. The measurement yielded proton induced polarization Py '. The data were compared with Faddeev calculations with high precision nucleon-nucleon
Physics of Unstable Nuclei - Proceedings of the International Symposium on the ISPUN07, 2008
Nuclear Physics A, 1999
Differential cross sections at 01a b = 0.0 ° 12.3 ° and a complete set of polarization transfer o... more Differential cross sections at 01a b = 0.0 ° 12.3 ° and a complete set of polarization transfer observables at 0,~b = 0.0 ° are measured for the 9°Zr(p, n) reaction at Tp = 295 MeV. A multipole decomposition analysis (MDA) technique is applied to the cross sections to deduce the Gamow-Teller (GT) strength B(GT). The obtained SZ-= ~2 B(GT) value is 28.0 4-1.6. The total spin transfer E is obtained for the continuum by using polarization transfer measurements. The SZ-S~+ value is deduced to be 27.0 and this is 90% of Ikeda's sum rule value of 3(N-Z)=30. Thus the quenching of the GT strength is small and the quenching mechanism due to the AN-admixture seems to play a minor role.
Modern Physics Letters A, 2003
The cross sections and spin observables of the p+d elastic scattering have been measured at 392 M... more 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.
Modern Physics Letters A, 2003
Dibaryons which have a very narrow decay width, called super-narrow dibaryons, are searched for b... more Dibaryons which have a very narrow decay width, called super-narrow dibaryons, are searched for by the p+d scattering at Ep = 295 MeV . The experiment was carried out at the Research Center for Nuclear Physics employing a two-arm magnetic spectrometer. A good mass resolution of 0.95 MeV and background free condition have been achieved. No resonance has been observed in the mass region of 1896–1914 MeV. The upper limits of the dibaryon production cross section have been determined.
Journal of Physics: Conference Series, 2011
View the article online for updates and enhancements. You may also like Elastic scattering studie... more View the article online for updates and enhancements. You may also like Elastic scattering studies of 16 C at 50 MeV/A on proton and deuteron targets with the CHIMERA multidetector at INFN-LNS L Grassi, C Agodi, F Amorini et al.-Design of plasma shutters for improved heavy ion acceleration by ultra-intense laser pulses M Matys, S V Bulanov, M Kucharik et al.
Few-Body Systems, 2014
Precise and large sets of cross section, vector A x , A y and tensor A x x , A xy , A yy analyzin... more Precise and large sets of cross section, vector A x , A y and tensor A x x , A xy , A yy analyzing power data for the 1 H (d, pp)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
AIP Conference Proceedings, 2008
Recent progress in our three nucleon force study with three nucleon scattering at intermediate en... more Recent progress in our three nucleon force study with three nucleon scattering at intermediate energies (E/A≈100 MeV) is presented, especially focusing on experimental deuteron‐proton elastic scattering and breakup reactions at RIKEN. One signature of three nucleon forces is identified in the cross section minimum for deuteron‐proton elastic scattering by direct comparison between precision data and state‐of‐the‐art Faddeev calculations based on realistic nucleon‐nucleon forces plus 2π‐exchange three nucleon forces. However, the polarization observables are not always well described by adding the model three nucleon forces, indicating that components other than a 2π‐exchange three nucleon force are required to describe the data.
Physical Review C, 2007
The cross section and several spin-dependent observables have been measured with high precision f... more The cross section and several spin-dependent observables have been measured with high precision for the reaction H(d, p)d at 90 MeV/nucleon. Several calculations were performed based either purely on two-nucleon potentials or also including three-nucleon potentials (3NP). The cross sections are consistent with all calculations including 3NPs. However, no single calculation reproduces the analyzing powers and spin-transfer coefficients, although some spin observables are reproduced to various degrees by the different calculations. A good understanding of the spin structure of 3NP is still lacking.
The three-nucleon system is the simplest, non-trivial testing ground which allows one to probe qu... more The three-nucleon system is the simplest, non-trivial testing ground which allows one to probe quantitatively modern nucleon-nucleon interaction models. The rigorous technique of solving the Faddeev equations for the three-nucleon system allows one to test the influence of additional dynamical ingredients, referred to as three-nucleon forces, as well as the Coulomb interaction and relativistic effects. A large set of high
AIP Conference Proceedings
In order to study the three-nucleon-force (3NF) effects in a Coulomb-free system, we have measure... more In order to study the three-nucleon-force (3NF) effects in a Coulomb-free system, we have measured nvec d elastic scattering (see Y. Maeda et al., in these proceedings). For the experiment, we produced self-supporting CD2 sheets from the CD2 powder obtained from C/D/N Isotopes Inc. We heated and pressed the CD2 powder in a mold. The mold was evacuated and filled with nitrogen gas for several times during the process of heating in order to avoid the oxidation. And we kept heating at 145 °C and pressing with 100 kgf/cm2 for 60 hours. We succeeded in producing CD2 targets with 0.3-4.0 mm thickness, 37×47 mm2 area and +/-20 mum uniformity of the thickness. .
Nuclear Many-Body and Medium Effects in Nuclear Interactions and Reactions, 2003
Precise measurements of the deuteron to proton polarization transfer coefficients for the d-p ela... more Precise measurements of the deuteron to proton polarization transfer coefficients for the d-p elastic scattering has 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, a modification thereof closer to chiral symmerty and Urbana-Argonne type of three nucleon forces.
Measurements of the tensor and vector analyzing powers Ayy, Axx, Axz, and Ay for the dvec d -->... more Measurements of the tensor and vector analyzing powers Ayy, Axx, Axz, and Ay for the dvec d --> 3Hen and dvec d --> 3Hp reactions were performed at Ed = 270 and 200 MeV over wide angular range. T20 at thetacm = 0° and 180° were also measured at Ed = 270, 200, and 140 MeV. Obtained data were compared
AIP Conference Proceedings, 2005
ABSTRACT To test Bell's inequality, measurements of spin correlations between two protons... more ABSTRACT To test Bell's inequality, measurements of spin correlations between two protons in the spin singlet state have been performed. Proton pairs in the singlet state were produced by the 1H(d,2He)n reaction at Ed = 270 MeV.
Nuclear Instruments and Methods in Physics Research, Section A: Accelerators, Spectrometers, Detectors and Associated Equipment, 2007
The 12C(d⇒,α)10B*[2+] reaction at 0∘ has been proposed as a new tool to calibrate the deuteron be... more The 12C(d⇒,α)10B*[2+] reaction at 0∘ has been proposed as a new tool to calibrate the deuteron beam polarization at intermediate energies. The absolute values of the deuteron polarizations were extracted for the first time by using this reaction at 270 and 140MeV deuteron energies. The analyzing powers for the d⇒–p elastic scattering, which is used as a secondary reaction of a polarimetry, were determined by the new method.
Physics Letters B, 2004
The data on the tensor analyzing power T 20 in the dd → 3 Hen and dd → 3 Hp reactions at 140, 200... more The data on the tensor analyzing power T 20 in the dd → 3 Hen and dd → 3 Hp reactions at 140, 200 and 270 MeV of the deuteron kinetic energy and at zero degree obtained at RIKEN Accelerator Research Facility are presented. The observed positive sign of T 20 clearly demonstrates the sensitivity to the D/S wave ratios in the 3 He and 3 H in the energy domain of the measurements. The T 20 data for the 3 Hen and 3 H-p channels are in agreement within experimental accuracy.
Physics Letters B, 2001
The deuteron single and double spin-flip probabilities, S 1 and S 2 , have been measured for the ... more The deuteron single and double spin-flip probabilities, S 1 and S 2 , have been measured for the 12 C(d, d ′) reaction at E d = 270 MeV for an excitation energy range between 4 and 24 MeV and a scattering angular range between Θ lab = 2.5 and 7.5 •. The extracted S 1 exhibits characteristic values depending on the structure of the excited state. The S 2 is close to zero over the measured excitation energy range. The SFP angular distribution data for the 2 + (4.44 MeV) and 1 + (12.71 MeV) states are well described by the microscopic DWIA calculations.
AIP Conference Proceedings, 2002
Precise data on cross sections, analyzing powers and polarization transfer coefficients are measu... more Precise data on cross sections, analyzing powers and polarization transfer coefficients are measured for the dp elastic scattering at 270 MeV (135 MeV/nucleon) and compared to Faddeev calculations assuming the nd scattering with modern nucleon-nucleon (NN) forces including the 2pi exchange Tucson-Melbourne (TM) three-nucleon (3N) force. Excellent fits are obtained for the cross sections and vector analyzing powers when the 3N force is included, while the fits are deteriorated for the tensor analyzing powers if the 3N force is included. A moderate fit is obtained for the polarization transfer coefficients. Based on theses results, one can conclude that the size of amplitudes of the TM-3N force may be adequate but the spin dependent part may be deficient. The cross sections and the vector analyzing powers for the nd elastic scattering at 250 MeV are measured for the first time. Backward cross sections are underestimated by the NN+3N force Faddeev calculations. This difference might be attributed to relativistic effects. .
A New Era of Nuclear Structure Physics, 2004
Precise data on the cross section and analyzing powers were measured for the d-p elastic scatteri... more Precise data on the cross section and analyzing powers were measured for the d-p elastic scattering at 70, 100 and 135 MeV/u. Also deuteron to proton polarization transfer coefficients Kyy' , Kxzy' , Kyyy' , Kxxy' were measured at 135 MeV/u. The measurement yielded proton induced polarization Py '. The data were compared with Faddeev calculations with high precision nucleon-nucleon
Physics of Unstable Nuclei - Proceedings of the International Symposium on the ISPUN07, 2008
Nuclear Physics A, 1999
Differential cross sections at 01a b = 0.0 ° 12.3 ° and a complete set of polarization transfer o... more Differential cross sections at 01a b = 0.0 ° 12.3 ° and a complete set of polarization transfer observables at 0,~b = 0.0 ° are measured for the 9°Zr(p, n) reaction at Tp = 295 MeV. A multipole decomposition analysis (MDA) technique is applied to the cross sections to deduce the Gamow-Teller (GT) strength B(GT). The obtained SZ-= ~2 B(GT) value is 28.0 4-1.6. The total spin transfer E is obtained for the continuum by using polarization transfer measurements. The SZ-S~+ value is deduced to be 27.0 and this is 90% of Ikeda's sum rule value of 3(N-Z)=30. Thus the quenching of the GT strength is small and the quenching mechanism due to the AN-admixture seems to play a minor role.
Modern Physics Letters A, 2003
The cross sections and spin observables of the p+d elastic scattering have been measured at 392 M... more 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.
Modern Physics Letters A, 2003
Dibaryons which have a very narrow decay width, called super-narrow dibaryons, are searched for b... more Dibaryons which have a very narrow decay width, called super-narrow dibaryons, are searched for by the p+d scattering at Ep = 295 MeV . The experiment was carried out at the Research Center for Nuclear Physics employing a two-arm magnetic spectrometer. A good mass resolution of 0.95 MeV and background free condition have been achieved. No resonance has been observed in the mass region of 1896–1914 MeV. The upper limits of the dibaryon production cross section have been determined.
Journal of Physics: Conference Series, 2011
View the article online for updates and enhancements. You may also like Elastic scattering studie... more View the article online for updates and enhancements. You may also like Elastic scattering studies of 16 C at 50 MeV/A on proton and deuteron targets with the CHIMERA multidetector at INFN-LNS L Grassi, C Agodi, F Amorini et al.-Design of plasma shutters for improved heavy ion acceleration by ultra-intense laser pulses M Matys, S V Bulanov, M Kucharik et al.
Few-Body Systems, 2014
Precise and large sets of cross section, vector A x , A y and tensor A x x , A xy , A yy analyzin... more Precise and large sets of cross section, vector A x , A y and tensor A x x , A xy , A yy analyzing power data for the 1 H (d, pp)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
AIP Conference Proceedings, 2008
Recent progress in our three nucleon force study with three nucleon scattering at intermediate en... more Recent progress in our three nucleon force study with three nucleon scattering at intermediate energies (E/A≈100 MeV) is presented, especially focusing on experimental deuteron‐proton elastic scattering and breakup reactions at RIKEN. One signature of three nucleon forces is identified in the cross section minimum for deuteron‐proton elastic scattering by direct comparison between precision data and state‐of‐the‐art Faddeev calculations based on realistic nucleon‐nucleon forces plus 2π‐exchange three nucleon forces. However, the polarization observables are not always well described by adding the model three nucleon forces, indicating that components other than a 2π‐exchange three nucleon force are required to describe the data.
Physical Review C, 2007
The cross section and several spin-dependent observables have been measured with high precision f... more The cross section and several spin-dependent observables have been measured with high precision for the reaction H(d, p)d at 90 MeV/nucleon. Several calculations were performed based either purely on two-nucleon potentials or also including three-nucleon potentials (3NP). The cross sections are consistent with all calculations including 3NPs. However, no single calculation reproduces the analyzing powers and spin-transfer coefficients, although some spin observables are reproduced to various degrees by the different calculations. A good understanding of the spin structure of 3NP is still lacking.
The three-nucleon system is the simplest, non-trivial testing ground which allows one to probe qu... more The three-nucleon system is the simplest, non-trivial testing ground which allows one to probe quantitatively modern nucleon-nucleon interaction models. The rigorous technique of solving the Faddeev equations for the three-nucleon system allows one to test the influence of additional dynamical ingredients, referred to as three-nucleon forces, as well as the Coulomb interaction and relativistic effects. A large set of high
AIP Conference Proceedings
In order to study the three-nucleon-force (3NF) effects in a Coulomb-free system, we have measure... more In order to study the three-nucleon-force (3NF) effects in a Coulomb-free system, we have measured nvec d elastic scattering (see Y. Maeda et al., in these proceedings). For the experiment, we produced self-supporting CD2 sheets from the CD2 powder obtained from C/D/N Isotopes Inc. We heated and pressed the CD2 powder in a mold. The mold was evacuated and filled with nitrogen gas for several times during the process of heating in order to avoid the oxidation. And we kept heating at 145 °C and pressing with 100 kgf/cm2 for 60 hours. We succeeded in producing CD2 targets with 0.3-4.0 mm thickness, 37×47 mm2 area and +/-20 mum uniformity of the thickness. .
Nuclear Many-Body and Medium Effects in Nuclear Interactions and Reactions, 2003
Precise measurements of the deuteron to proton polarization transfer coefficients for the d-p ela... more Precise measurements of the deuteron to proton polarization transfer coefficients for the d-p elastic scattering has 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, a modification thereof closer to chiral symmerty and Urbana-Argonne type of three nucleon forces.
Measurements of the tensor and vector analyzing powers Ayy, Axx, Axz, and Ay for the dvec d -->... more Measurements of the tensor and vector analyzing powers Ayy, Axx, Axz, and Ay for the dvec d --> 3Hen and dvec d --> 3Hp reactions were performed at Ed = 270 and 200 MeV over wide angular range. T20 at thetacm = 0° and 180° were also measured at Ed = 270, 200, and 140 MeV. Obtained data were compared
AIP Conference Proceedings, 2005
ABSTRACT To test Bell's inequality, measurements of spin correlations between two protons... more ABSTRACT To test Bell's inequality, measurements of spin correlations between two protons in the spin singlet state have been performed. Proton pairs in the singlet state were produced by the 1H(d,2He)n reaction at Ed = 270 MeV.
Nuclear Instruments and Methods in Physics Research, Section A: Accelerators, Spectrometers, Detectors and Associated Equipment, 2007
The 12C(d⇒,α)10B*[2+] reaction at 0∘ has been proposed as a new tool to calibrate the deuteron be... more The 12C(d⇒,α)10B*[2+] reaction at 0∘ has been proposed as a new tool to calibrate the deuteron beam polarization at intermediate energies. The absolute values of the deuteron polarizations were extracted for the first time by using this reaction at 270 and 140MeV deuteron energies. The analyzing powers for the d⇒–p elastic scattering, which is used as a secondary reaction of a polarimetry, were determined by the new method.
Physics Letters B, 2004
The data on the tensor analyzing power T 20 in the dd → 3 Hen and dd → 3 Hp reactions at 140, 200... more The data on the tensor analyzing power T 20 in the dd → 3 Hen and dd → 3 Hp reactions at 140, 200 and 270 MeV of the deuteron kinetic energy and at zero degree obtained at RIKEN Accelerator Research Facility are presented. The observed positive sign of T 20 clearly demonstrates the sensitivity to the D/S wave ratios in the 3 He and 3 H in the energy domain of the measurements. The T 20 data for the 3 Hen and 3 H-p channels are in agreement within experimental accuracy.
Physics Letters B, 2001
The deuteron single and double spin-flip probabilities, S 1 and S 2 , have been measured for the ... more The deuteron single and double spin-flip probabilities, S 1 and S 2 , have been measured for the 12 C(d, d ′) reaction at E d = 270 MeV for an excitation energy range between 4 and 24 MeV and a scattering angular range between Θ lab = 2.5 and 7.5 •. The extracted S 1 exhibits characteristic values depending on the structure of the excited state. The S 2 is close to zero over the measured excitation energy range. The SFP angular distribution data for the 2 + (4.44 MeV) and 1 + (12.71 MeV) states are well described by the microscopic DWIA calculations.