Lifetime measurement of higher-lying excited states in ¹⁶C

Electromagnetic properties of the neutron-rich carbon isotopes provide an exciting opportunity to directly test theoretical models using NN+3N Hamiltonians derived from chiral EFT. Indeed, the EM properties of ¹⁶C are particularly sensitive to the inclusion of 3N forces in the calculations. However, the experimental information on ¹⁶C are limited to the lifetime of the first excited state and an upper limit of 4 ps for the higher-lying states. To investigate lifetimes and branching ratios of the higher-lying states (2₂⁺,3⁺,4⁺) a fusion-evaporation reaction has been performed at the Argonne National Laboratory. Evaporated charged particles were identified using the μ-Ball detector and emitted gamma rays were identified using the Gammasphere array. Lifetimes of the excited states can be extracted using the doppler shift attenuation method. In the talk the measurement techniques and preliminary gamma spectra of ¹⁶C, which can be used to give a first approximation of the magnitude of the lifetime, are presented.