High-precision vector and tensor analyzing powers of elastic deuteron-proton ( d + p) scattering have been measured at intermediate energies to investigate effects of three-nucleon forces. Angular distributions in the range of 70°-120° in the center-of mass frame for incident-deuteron energies E d lab = 130 and 180 MeV were obtained using the RIKEN facility. The beam polarization was unambiguously determined by measuring the ^12C (d, α)^10B(2+) reaction at 0°. Results of the measurements are compared with state-of-the-art three-nucleon calculations. The present modeling of nucleon-nucleon forces and its extension to the three-nucleon system is not sufficient to describe the high-precision data consistently and requires, therefore, further investigation.

H. Mardanpour, H. R. Amir-Ahmadi, A. Deltuva, K. Itoh, N. Kalantar-Nayestanaki, T. Kawabata, H. Kuboki, Y. Maeda, J. G. Messchendorp, S. Sakaguchi, H. Sakai, N. Sakamoto, Y. Sasamoto, M. Sasano, K. Sekiguchi, K. Suda, Y. Takahashi, T. Uesaka, H. Witała, K. Yako.
Precision measurement of vector and tensor analyzing powers in elastic deuteron-proton scattering,
The European Physical Journal A,
2007, 383-391, DOI: 10.1140/epja/i2006-10228-0