Search for Alpha particle Condensation in $^{16}$O

Recently, Tohsaki \textit{et al} were proposed the $\alpha $ particles condensed state existed in the vicinity of the threshold energy that decay into 3- and 4-$\alpha $ particles in the $^{12}$C and $^{16}$O nuclei.The energy state of the 4-$\alpha $ particles condensation has not been specified yet in $^{16}$O though it is considered that the second 0$^{+}$ state (7.65MeV) in $^{12}$C is the 3-$\alpha $ particles condensed one theoretically. To verify the existence of the $\alpha $ condensation in $^{16}$O, we have performed the experiment on the $^{12}$C($^{16}$O,$^{16}$O*[X+$\alpha $]) $^{12}$C reaction. The probability of the 4-$\alpha $ particles condensed state of $^{16}$O decays to 3-$\alpha $ condensed one of $^{12}$C and an $\alpha $ particle is large.Therefore,we investigate the excited state in $^{16}$O by obtaining the branching ratio of each decay channel of $^{16}$O*$\to ^{12}$C (0$_{2}^{+})+\alpha $,$^{ 16}$O*$\to ^{12}$C (2$_{1}^{+})+\alpha $,$^{ 16}$O*$\to ^{12}$C (g.s) +$\alpha $.In this talk, We will report on result of the experiment and the MonteCalro simulation in $^{16}$O for excited state of 15.1MeV which was one of candidates for the 4-$\alpha $ condensation.