The emission of high-energy gamma-rays in the deexcitation of hot Ca-40 and K-39 nuclei formed in heavy-ion fusion reactions at excitation energy E(x) similar to 90 MeV has been studied. The high energy gamma-rays were measured in coincidence with evaporation residues or light charged particles. The gamma spectrum from the self-conjugated compound nucleus Ca-40 shows an appreciable yield suppression in the Giant Dipole Resonance (GDR) energy region with respect: to the K-39, due to isospin selection rules in the dipole gamma-decay. The spectral line shapes of the gamma spectra are well reproduced by using a statistical code which treats explicitly the isospin quantum number in evaluating level densities and transmission coefficients. The GDR parameters determined from the present coincidence measurements are in good agreement with the systematic in the A similar to 40 mass region at lower bombarding energy based on the analysis of inclusive spectra.
GIANT-DIPOLE RESONANCE IN A-SIMILAR-TO-40 HOT NUCLEI FROM COINCIDENCE MEASUREMENTS / Cinausero, M.; Gelli, N.; Lucarelli, Franco; Blasi, Paolo; Fioretto, E.; Gramegna, F.; Prete, G.; Fabris, D.; Nebbia, G.; Viesti, G.; Fiore, E. M.; Fiore, L.; Paticchio, V.; Bortignon, P. F.. - In: ZEITSCHRIFT FÜR PHYSIK. A, HADRONS AND NUCLEI. - ISSN 0939-7922. - STAMPA. - 352:(1995), pp. 273-277. [10.1007/BF01289500]
GIANT-DIPOLE RESONANCE IN A-SIMILAR-TO-40 HOT NUCLEI FROM COINCIDENCE MEASUREMENTS
LUCARELLI, FRANCO;BLASI, PAOLO;
1995
Abstract
The emission of high-energy gamma-rays in the deexcitation of hot Ca-40 and K-39 nuclei formed in heavy-ion fusion reactions at excitation energy E(x) similar to 90 MeV has been studied. The high energy gamma-rays were measured in coincidence with evaporation residues or light charged particles. The gamma spectrum from the self-conjugated compound nucleus Ca-40 shows an appreciable yield suppression in the Giant Dipole Resonance (GDR) energy region with respect: to the K-39, due to isospin selection rules in the dipole gamma-decay. The spectral line shapes of the gamma spectra are well reproduced by using a statistical code which treats explicitly the isospin quantum number in evaluating level densities and transmission coefficients. The GDR parameters determined from the present coincidence measurements are in good agreement with the systematic in the A similar to 40 mass region at lower bombarding energy based on the analysis of inclusive spectra.
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