Examination of level density prescriptions for the interpretation of high-energy γ-ray spectra

High-energy gamma-ray spectra measured by our group involving the compound nuclei (CN) Cu-63 at excitation energy E* similar to 36 MeV with average angular momentum J = 12-17 (h) over bar, Tc-97 at E* similar to 29-50 MeV with J = 12-14 (h) over bar, Sb-113 at E* = 109 and 121 MeV with J = 49-59 h, and Tl-201 at E* = 39.5 and 47.5 MeV with J = 18-24 h have been analyzed utilizing the level density prescriptions of (i) Ignatyuk, Smirenkin, and Tishin (IST), (ii) Budtz-Jorgensen and Knitter (BJK), and (iii) Kataria, Ramamurthy, and Kapoor (KRK). These three prescriptions have been tested for the correct statistical model description of high-energy gamma-ray in the light of extracting the giant dipole resonance (GDR) parameters at low excitation energy and spin where shell effects might play an important role, as well as at high excitation energy where shell effects have melted. Interestingly, only the IST level density prescription could explain the high-energy gamma-ray spectra with reasonable GDR parameters for all four nuclei.