FIG. 9: (Color online) ISGMR strength distributions obtained for the Sn isotopes in the present experiment. Error bars represent the uncertainties from fitting the angular distributions in the MDA procedure. The solid lines show Lorentzian fits to the data. in this experiment. The raison d‘ˆ etre of this extra strength is not quite well understood. However, similarly enhanced E1 strengths at high excitation energies were noted previously [29, 30] and have been attributed to contributions to the continuum from three-body chan- nels, such as knockout reactions [44]. These processes are implicitly included in the MDA as background and may lead to spurious contributions to the extracted multipole strengths at higher energies where the associated cross sections are very small. This conjecture is sup- ported by measurements of proton decay from the ISGDR at backward angles wherein no such spurious strength is observed in spectra in coincidence with the decay protons [31, 56– 58]; quasifree knockout results in protons that are forward peaked. A similar increase in the ISGMR strength at high excitation energies was reported as well by the TAMU group in $^{12}$C when they carried out MDA without subtracting the continuum from the excitation-energy spectra [18]. The L = 0 strength distributions were fitted with a Lorentzian function to determine the centroid energies and widths of the ISGMR. These fits are shown superimposed in 13