Electromagnetic polarizabilities of nucleons bound in 12C and 16O

Compton scattering from6Li at 60 MeV

“…This result gives confidence that the absolute cross-section extraction does not suffer from any unknown systematic effects. 16 O obtained by [18,19] and [20,21] and current results. Statistical errors are shown on the data points.…”

“…Figure 6 shows the previous 16 O data from Lund [18,19] and the Saskatchewan Accelerator Laboratory (SAL) and University of Illinois collaboration [20,21]. The Lund data were collected at 58 MeV and the SAL/Illinois at 60 MeV.…”

“…Compton scattering measurements directly off the neutron are not possible due to the lack of a free neutron target. As such, experimenters have had to resort to using light nuclei such as [18][19][20][21] to try to measure α n and β n . The results for the heavier nuclei are ambiguous due to uncertainties in the model parameterizations.…”

Compton scattering fromC12using tagged photons in the energy range 65–115 MeV

“…The results are also shown in Fig. 5, along with the results from [10][11][12][13] above 55 MeV. The new data are in excellent agreement with the results from Schelhaas et al [10] and Warkentin et al [13].…”

“…[8] 12 C [9], [10], [11], [12], [13] 16 O [7], [8], [11], [12], [14], [15] 40 Ca [7], [9] It is also reasonable to ask whether the nucleon polarizabilities are modified when the proton or neutron is bound in a nucleus and, if so, to what degree. A multitude of Compton-scattering experiments have been carried out with a variety of light nuclei (see Table I) for the purpose of determining the bound-nucleon polarizabilities (α eff and β eff ) given by α eff = α N + ∆α, β eff = β N + ∆β, (6) where α N and β N are the nucleon-averaged free polarizabilities and ∆α and ∆β represent the nuclear modifications [13] which can be extracted from the scattering data.…”