The nuclear spin alignments of the β-emitting fragments 12B(Iπ = 1+, T1/2 = 20.2 ms) and 13B(Iπ = 3/2-, T1/2 = 17.4 ms) produced in the 100A-MeV 13C, 15N + 9Be collisions respectively have been observed for the first time detecting asymmetric β-ray emission from these nuclei. By means of the spin manipulation technique based on the hyperfine interaction of B isotopes in TiO2, both the polarization P and the alignment A were determined reliably. The obtained P and A were significantly smaller than the expectation from the kinematical model. From the fact that the quenching factors for P and A are almost the same, there may be some depolarization mechanism in the collision process itself.
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