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dc.contributor.authorPitthan, R.
dc.contributor.authorBuskirk, F.R.
dc.contributor.authorDally, E.B.
dc.contributor.authorShannon, J.O.
dc.contributor.authorSmith, W.H.
dc.date.accessioned2016-01-11T23:53:29Z
dc.date.available2016-01-11T23:53:29Z
dc.date.issued1977-09
dc.identifier.citationPhysical Review C, v. 16, no. 3, September 1977, pp. 970-982en_US
dc.identifier.urihttp://hdl.handle.net/10945/47513
dc.description.abstract92.5 MeV electrons were used to study in (89)Y the excitation range between 2 and 55 MeV. Above neutron threshold, broad electric resonances have been seen at 14.0 (63A(-1/3) MeV (E2, vT = 0) and 28 (125A-(1/3) MeV (E2, vT = 1). The total width of the isoscalar E2 resonance is (4.5 +/-0.4) MeV and its strength (56 =/- 6) % energy-weighted sum rule (E2, vT = 0). For the isovector E2 resonance only a minimal value of 7 MeV for the width can be given which is connected with (48 +/- 5)% of the isovector sum rule. The strength of the E1 resonance [T>7(104 =/- 10)% of the Thomas-Reiche-Kuhn sum rule] agrees well with (y,n) measurements, thus giving a check for the accuracy of the evaluating methods employed. A structure around 19-20 MeV, believed to be the T> part of the giant dipole resonance, carries (8 +/- 3)% of the E1 sum rule. In addition to these generally well known states, clustering of E3 strength, (13 +/- 2)% energy-weighted sum rule (E3, vT = 0), was found at 6.75 and 80.5 MeV; the enveloping line shape of these clusters was best described by a Breit-Wigner term. Other concentrations of strength include E3 at 2.6 MeV, (15 +/-3)% energy-weighted sum rule E3, (vT = 0), E2 at 4.0 MeV, (11 +/- 3)% energy-weighted sum rule (E2, vT = 0), and E3 strength at 13.5 MeV. No resonance other than the E1 was found around 17 MeV, thus ruling out in (89)Y the existence of a monopole state with 100% sum rule proposed for (90)Zr from (a,a') and (e,e') measurements. In contrast to heavy nuclei, no resonant 3hw E3 strength could be located.en_US
dc.format.extent13 p.en_US
dc.rightsThis publication is a work of the U.S. Government as defined in Title 17, United States Code, Section 101. Copyright protection is not available for this work in the United States.en_US
dc.titleGiant resonances and bound collective states observed in the scattering of 92.5-MeV electrons from the closed-neutron-shell nucleus Y89 between excitation energies from 2.0 to 55 MeVen_US
dc.typeArticleen_US
dc.contributor.corporateNaval Postgraduate School (U.S.)en_US
dc.contributor.departmentPhysics and Chemistryen_US


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