Experimental evidence for signature inversion in ~(132)La from a revisited level scheme

摘要

The decay out of the πh_(11/2)vh_(11/2) band to the known low-energy levels in ~(132)La was studied using the reaction ~(100)Mo+~(36)S at 160 MeV beam energy. The low-energy level scheme has been further developed and unambiguous spin and parity values have been assigned to the levels connecting the band to the 6~- isomeric state. According to the new level scheme the spins in the πh_(11/2)vh_(11/2) band are shifted up by one unit compared to the earlier tentative experimental values. The obtained new spins prove the existence of signature inversion in ~(132)La and give further support to the spin assignments made for the πh_(11/2)vh_(11/2) bands in the neighbouring odd-odd La isotopes from level energy systematics.