Isoscalar Multipole Resonances inCa40

Abstract

A correlation experiment between inelastically scattered ^He particles at 1.2° and decay a particles was performed in the giant-resonance region of ^^Ca at an incident energy of 120 MeV. A new O"*" state with 6% energy-weighted sum-rule strength was observed at E^=1A,2 MeV. Two broad resonances (quadrupole and possibly octupole) were observed at E^'^ 18 MeV. No resonant structure was observed at E > 20 MeV.

Experimental determination of monopole strength in 40Ca between 10 and 20 MeV excitation energy

“…The results of the two independent determinations of the E0 strength are in good agreement. Also the agreement with the prevmusly reported values is good: the structure at E x = 14.17 MeV has been reported to exhaust (6 + 3)% [16] and (6-7)% of the E0 EWSR [12], while the amount of E0 strength found between E x = 15.7 MeV and 20 MeV is in agreement with the suggestions of refs. [1,6,17].…”

“…In the first place previous RPA calculations [8,9] predict that there should be a compact monopole resonance located somewhere between 20 and 25 MeV excitation, while a more recent calculation m the framework of the selfconslstent continuum RPA predicts that the monopole strength in 40Ca should be fragmented [10]. The other reason is that nearly all experiments [1,6,[11][12][13][14][15][16][17] the E0 EWSR in the region betv een 16 and 20 MeV excitation energy [1,6]. We have used two independent methods to determine monopole strength, both of which have been used previously, but only separately or at least not mdependently as m the present experiment: singles measurements and coincidences with a-decay to the 0 + ground state of the residual nucleus 36At at very forward scattering angles.…”

Systematics of the isoscalar giant monopole resonance from 60 MeV inelastic proton scattering

“…The EWSR depletion for the GQR deduced for these nuclei is in good agreement between the two experiments. For 4°Ca our analysis of the GQR is consistent with recent results from small- angle (r, r') measurements [10]. Cross sections for the GMR-GDR peak are plotted in fig.…”

“…(A small mixture ofL = 0 (~< 15%) could be consistent within the uncertainty on the data.) This result agrees with recent 40Ca(7., 7-') measurements [10].…”

Quadrupole Radiation in Fast-Neutron Capture onCa40

“…The reported value of 26% was used for case 2. 19 One exception to the good agreement is the large negative value of a s at 6 MeV. This may indicate some fragmentation of the collective quadrupole resonance similar to that observed in 40 Ca by Youngblood et al 20 Elastic scattering of 104-MeV a particles from ^'^Ca was measured between 3° and 110°.…”