Experimental study of resonance line-shapes in ¹²C( tau ,d) stripping into the continuum

Deuteron spectra from the ¹²C( tau ,d) reaction leading to excitation energies in ¹³N of more than 4 MeV above the proton threshold have been measured at angles between 7 degrees and 20 degrees . The spectra exhibit the broad d_3/2 single-particle resonance of ¹²C+p and, interfering with it, the 120 keV wide ³/₂⁺ resonance at E_x=6.885 MeV in ¹³N. The line-shape of the ⁵/₂⁺ resonance at E_x=6.364 MeV also displays a pronounced interference pattern. An observed angle dependence of the resonance profile is interpreted as indication for contributions from the nuclear interior.