ReactionAr38(d,p)Ar

Abstract

The level structure of 3 Ar has been investigated via the stripping reaction Ar(d, p)~A r at an incident deuteron energy of 10.064 MeV with an over-all experimental resolution of approximately 35 keV. Proton groups leading to 44 states of Ar with excitation energies up to 7.727 MeV have been identified. 30 of these states with excitation energies up to 6.488 MeV are neutron-bound.The orbital-angular-momentum-transfer values and the spectroscopic factors have been extracted for 28 of the observed neutron-bound states using zero-range distorted-wave Born-approximation (DWBA) calculations corrected for nonlocality of the optical potential and finite range in the local-energy approximation. One l =0, one l =2, twelve l =3, and fourteen l =1 transfer values are assigned. Spin assignments have been made on the basis of the conventional shell-model ordering of states, by comparison with the level structure of the isotonic nucleus Ca in the reaction Ca(d, p)4 Ca and on the basis of the Lee-Schiffer effect. It is found that the conventional DWBA calculation with spin-orbit coupling reproduces the observed Lee-Schiffer effect for l =1 states remarkably well. The results of the present investigation are in fair agreement with those of recent shell-model calculations.

Isobaric analog resonances of theN=21nucleus35Si

“…In the common picture explaining the shell breaking, there remain problems in the shell structure in this region. The experimental results for the spin-parity J π of the ground state in 33 Mg obtained in various studies are inconsistent with each other [8][9][10][11].…”

“…The systematics of J π for the second l = 1 state in N = 21 nuclei suggests J π = 3/2 − of this parent state. Although the present S value of 0.12(7) is close to the S = 0.17 of the second 3/2 − in 41 Ca [34], the corresponding values for 39 Ar [33] and 37 S [32] are 0.08, 0.03, respectively, which do not show any systematic trend. In the case of J π = 1/2 − , p and tot change to 58.0(160) and 58.0(180) keV, respectively.…”

“…A level scheme for 35 Si, proposed by taking into account the β decay study and the present results, is compared with those of 33 Mg and 37 S in Fig. 3(c).…”

“…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.…”