A 36S(d,p) study with high energy resolution

Isobaric analog resonances of theN=21nucleus35Si

“…As followed the assignment of the β decay study, when J π = 3/2 + is assumed for the l = 2 state, the obtained p and tot change to 41.0 (108) keV and 86.5(265) keV, respectively. S increases accordingly to 1.21 (32). The S values are much larger than expected values of S 0.05 and 0.5, respectively, from the systematics.…”

“…Several experimental works have studied the nuclear structure around 32 Mg, and the results are consistently interpreted as showing that the magic number N = 20 disappears in this region. The first evidence of this was obtained by measuring the enhanced two-neutron separation energy of 31,32 Na [5].…”

“…The systematic errors were estimated to be 13%, which mainly come from that of the cross sections. The systematics of S for the bound states at the low-lying states in N = 21 nuclei, which were obtained by (d,p) reactions [32][33][34], suggest that the f or p states have S = 0.5 ∼ 0.8, whereas the s or d states, which are considered to be hole states have S 0.05.…”

“…Around 5 MeV, we observed two peaks. [32]) and 33 Mg (Yordanov [9], Tripathi [10]) are shown for comparison in (d) and (e), respectively.…”

“…A sudden decrease of the energy of the first 2 + state from 3.33 to 0.88 MeV for 34 Si and 32 Mg [4,6], respectively, suggests that the onset of the deformation starts at 32 Mg, not at 34 Si. More direct evidence was obtained from comparing the enhanced quadrupole collectivities for 32 Mg [3] and 34 Si [7]. In the common picture explaining the shell breaking, there remain problems in the shell structure in this region.…”