New evidence of the Hoyle-like structure in ¹⁶O

An experiment of ¹²C(¹⁶O,¹⁶O → 4α)¹²C was performed at a beam energy of 96 MeV. A large number of 4-α events were recorded in coincidence and with full particle identification (PID). This was made possible by employing a series of silicon-strip-based telescopes that provided excellent position and energy resolutions. Four narrow resonances just above the 15.1 MeV state were firmly identified in the α + ¹²C(7.65 MeV; Hoyle state) decay channel. Combined with the theoretical predictions, these resonant states provide new evidence for the predicted possible Hoyle-like structure in ¹⁶O above the 4-α separation threshold. Some very high-lying 4-α resonant states have also been observed and need to be further investigated.