Tensor polarization of $^{12}$C[ 2$^+_1$] in the $^{16}$O($^{13}$C,$^{12}$C)$^{17}$O reaction at 50 MeV

N. Ikeda; F. Nakamura; K. Mizuuchi; T. Sugimitsu; S. Teruyama; T. Okamoto; H. Fujita; S. Morinobu

doi:doi:10.1007/PL00013650

2022 Impact factor 2.7

Hadrons and Nuclei

Eur. Phys. J. A 7, 491-502

Tensor polarization of ¹²C[2⁺₁] in the ¹⁶O(¹³C,¹²C)¹⁷O reaction at 50MeV

N. Ikeda¹ - F. Nakamura¹ - K. Mizuuchi¹ - T. Sugimitsu¹ - S. Teruyama¹ - T. Okamoto¹ - H. Fujita² - S. Morinobu¹

¹ Department of Physics, Kyushu University, Fukuoka 812-8581, Japan
² Daiichi College of Pharmaceutical Sciences, Fukuoka 815-8511, Japan

Received: 2 August 1999 / Revised version: 3 February 2000 Communicated by K. Nakai

Abstract
The ¹⁶O(¹³C,¹²C)¹⁷O reaction at 50MeV has been investigated using the kinematical coincidence method. Polarization tensors t₂₀ and t₄₀ of ¹²C[2⁺₁] for the quantization axis taken along the direction of propagation have been measured by analyzing the energy spectrum of ¹²C[2⁺₁], modulated by the effect of $\gamma$ ray emission. The deduced t₄₀ values significantly deviate from zero, contrary to the prediction of the distorted-wave Born approximation theory based on one-step p shell neutron stripping without spin-dependent interactions. The phenomenological spin-orbit interaction necessary to reproduce the magnitude of measured t₄₀ is found to be much larger than the folding model prediction. It is shown that the experimental polarization tensors as well as the cross sections can be reproduced by introducing multi-step processes involving excitations in ¹²C and ¹³C without introducing spin-dependent interactions.