Examining the exotic structure of the proton-rich nucleus Al-23

[著者版]The longitudinal momentum distribution (P-//) of fragments after one-proton removal from Al-23 and reaction cross sections (sigma(R)) for Al-23,Al-24 on a carbon target at 74A MeV have been measured. The Al-23,Al-24 ions were produced through projectile fragmentation of 135A MeV Si-28 primary beam using the RIPS fragment separator at RIKEN. P-// is measured by a direct time-of-flight (TOF) technique, while sigma(R) is determined using a transmission method. An enhancement in sigma(R) is observed for Al-23 compared with Al-24. The P-// for Mg-22 fragments from Al-23 breakup has been obtained for the first time. FWHM of the distributions has been determined to be 232 +/- 28 MeV/c. The experimental data are discussed by using the Few-Body Glauber model. Analysis of P-// demonstrates a dominant d-wave configuration for the valence proton in ground state of Al-23, indicating that Al-23 is not a proton halo nucleus