Investigation of 6 He cluster structures

The α+2n and t+t clustering of the 6He ground state were investigated by means of the transfer reaction 6He( p, t)4He at 25 MeV/nucleon. The experiment was performed in inverse kinematics at GANIL with the SPEG spectrometer coupled to the MUST array. Experimental data for the transfer reaction were analyzed by a distorted wave Born approximation (DWBA) calculation, including the two neutrons and the triton transfer. The couplings to the 6He → 4He+ 2n breakup channels were taken into account with a polarization potential deduced from a coupled-discretized-continuum channels analysis of the 6He+ 1H elastic scattering measured at the same time. The influence on the calculations of the α+t exit potential and of the triton sequential transfer is discussed. The final calculation gives a spectroscopic factor close to one for the α+2n configuration as expected. The spectroscopic factor obtained for the t+t configuration is much smaller than the theoretical predictions.