The structure of 113Sn from proton and alpha- particle induced reactions.

The results of in-beam investigations of ¹¹³ Sn using the (p,n), (p,3n), (α,n) and (α,2n) reactions are summarized. Excited states have been identified until E_x = 4715 MeV and J^π = (27/2^{t -}). For a large number of levels mean lifetimes τ have been determined with the DSA method. For the J^k = 25/2⁺ state at E_x = 4059 MeV, τ = 1.0(4) ns has been measured with the γ-RF method. The experimental results are compared with the predictions of shell-model calculations. Most of the positive-parity states may be considered as one-or three-quasiparticle neutron excitations of the 2d_5/2, 1_g7/2, 3_s1/2 and 2d_3/2 shells, the negative-parity states as the coupling of one 1h_11/2 neutron to the two- or four-quasiparticle neutron excitations in the even-mass ¹¹²Sn core. For the 25/2⁺ isomer the three-quasiparticle neutron configuration ν(h₁₁^2/2 g₇^2/−1) has been proposed on the basis of a shell-model analysis using the mass-formula formalism. The experimentally observed yrast states in ₅₀¹¹³Sn₆₃ are compared with the corresponding states in the valence mirror nucleus ₆₃¹⁴⁵Eu82 giving remarkable similarities although the parameters for the shell-model calculations differ considerably. The analysis of nearest-neighbour spacing distributions of experimentally obtained 5/2⁺ states in ¹¹³Sn does not allow definite conclusions about regularity or chaos. [ABSTRACT FROM AUTHOR]