Abstract
The partial one-neutron removal cross section of 24 O leading to the first ex- cited state in 23 O has been measured to be 65.7 5.3 mb with a proton target in inverse kinematics at the beam energy of 62 MeV/nucleon. The decay energy spectrum of the neutron unbound state of 23 O was reconstructed from the measured four momenta of 22 O and the emitted neutron. A sharp peak was observed at Edecay = 48 3 keV, confirming the previous measurements. The measured partial longitudinal momentum distribution of 23 O showed the d-wave knockout character, providing a support for the J assignment of 5/2 + for this state. The spectroscopic factor for the neutrons in 0d5=2 orbital was deduced, for the first time, to be C 2 S (0d5=2) = 3.7 0.3 (preliminary) by comparing with the result of Glauber model. The relatively large spectroscopic factor supports the N = 16 shell closure in the neutron drip-line nucleus 24 O.
Highlights
A relatively large spectroscopic factor is indicative of a strong neutron occupancy in 0d5/2 orbital, providing a support of the N = 16 spherical shell closure in 24O
The experiment was performed at the RIPS facility [7] at RIKEN
The liquid-hydrogen (LH2) target [9] was installed at the achromatic focus F3 of RIPS
Summary
Confirmed the N = 16 spherical shell closure of 24O from the measurement of large spectroscopic factor C2S (1s1/2) = 1.74 ± 0.19 reflecting the occupation number of the neutrons in 1s1/2 orbital. The excitation energy and the longitudinal momentum distribution of 23O∗ have been measured to identify the 0d5/2 neutron hole state. A relatively large spectroscopic factor is indicative of a strong neutron occupancy in 0d5/2 orbital, providing a support of the N = 16 spherical shell closure in 24O.
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
