Coulomb Dissociation of $^{12}$N and $^{13}$O

T.\ Minemura$^A$, T.\ Motobayashi$^A$, S.\ Shimoura$^D$, H.\ Murakami$^B$, Y.\ Ando$^B$, Y.\ Yanagisawa$^A$, Y.\ Iwata$^B$, S.\ Ozawa$^A$, S.\ Takeuchi$^A$, Y.\ Higurashi$^A$, K.\ Yamada$^B$, T.\ Gomi$^B$, M.\ Serata$^B$, H.\ Kobayashi$^B$, N.\ Aoi$^A$, M.\ Hirai$^C$, H.\ Iwasaki$^C$, K.\ Yoshida$^A$, N.\ Iwasa$^E$ M.\ Kurokawa$^D$, H.\ Akiyoshi$^A$, Zs.\ F\"ul\"op$^{A,}$ H.\ Sakurai$^C$, T.\ Teranishi$^D$, Z.\ Liu$^A$, M.\ Ishihara$^A$ $^A$RIKEN $^B$Department of Physics, Rikkyo University $^C$Department of Physics, University of Tokyo $^D$Center for Nuclear Study (CNS), University of Tokyo, $^E$Department of Physics, Tohoku University ---The Coulomb breakup technique was employed to determine the radiative width of excited levels in $^{12}$N and $^{13}$O, which dominate the low-energy cross sections of the $^ {11}$C(p,$\gamma$)$^{12}$N and $^{12}$N(p,$\gamma$)$^{13}$O reactions. The $^{12}$N and $^{13}$O radioactive beams were produced through transfer and fragmentation reactions of aprimary 135~MeV/nucleon $^{16}$O beam at RIKEN. For the $^{12}$N-dissociation experiment, the radiative width of the 2$^-$ state at $E_{\rm{ex}}$=1.19~MeV in $^{12}$N was extracted to be $\Gamma_{\gamma}$=29.0$\pm$4.1~meV, the accuracy of which has been much improved compared with earlier studies. For $^{13}$O, large E1 strength was found for the first time at around $E_{\rm x}$=2.5~MeV. By the present study, the accuracy of the low-energy photo- capture cross sections for $^{11}$C and $^{12}$N have been improved, and reaction rates are now calculable based on more reliable experimental informations.