Search for: All records

Abstract Low-lying states in$$^{54}$$ $_{}^{54}$ Cr have been investigated via the$$\alpha $$ $\alpha$ -transfer reaction$$^{50}$$ $_{}^{50}$ Ti($$^{7}$$ $_{}^7$ Li,t) at a bombarding energy of 20 MeV. The exclusive$$\alpha $$ $\alpha$ -transfer channel is separated from other reaction channels through the appropriate energy gate on the complementary particle, triton. Levels of$$^{54}$$ $_{}^{54}$ Cr populated exclusively by the$$\alpha $$ $\alpha$ -transfer process could be identified up to$$\approx $$ $\approx$ 5 MeV excitation energy and angular momentum up to$$(8)^{+}$$ ${\left(8\right)}^{+}$ , by identifying the corresponding known$$\gamma $$ $\gamma$ -rays. These include multiple low-lying non-yrast 2$$^+$$ $_{}^{+}$ and 4$$^+$$ $_{}^{+}$ states, which would otherwise be unfavorable via fusion evaporation reactions. The feeding-subtracted$$\gamma $$ $\gamma$ -ray yields have been extracted to estimate the population of various excited states through the transfer process. The measured integrated transfer cross sections for all the observed yrast and non-yrast states are compared with Coupled Channels calculations usingfrescoto extract the$$\alpha $$ $\alpha$ +$$^{50}$$ $_{}^{50}$ Ti core spectroscopic factors. For the yrast states, a higher$$\alpha $$ $\alpha$ +core overlap is seen for the$$2^+$$ $2^{+}$ and$$4^+$$ $4^{+}$ states, while it is seen to be less favorable for the$$6^+$$ $6^{+}$ and$$(8)^+$$ ${\left(8\right)}^{+}$ states when$$\alpha $$ $\alpha$ -transfer is considered to occur predominantly as a direct one-step process to the$$^{50}$$ $_{}^{50}$ Ti core ground state. The yrast$$2^+$$ $2^{+}$ , and$$4^+$$ $4^{+}$ states are predominantly populated by single-step transfer, while for the states with spin$$\ge $$ $\ge$ 5, the possibility of core excitation followed by$$\alpha $$ $\alpha$ -transfer shows a larger$$\alpha $$ $\alpha$ -core overlap. For the non-yrast$$0^+$$ $0^{+}$ ,$$2^+$$ $2^{+}$ , and$$4^+$$ $4^{+}$ states, single-step transfer shows moderate to small$$\alpha $$ $\alpha$ -core overlap. No higher spin non-yrast states are observed.