The (α, α), (α, α′) and (α, 3He) reactions on 12C at 139 MeV

The alpha optical potential at 1,370 MeV

“…The magnitude of RSA at 1,370 MeV, however, is significantly smaller than at lower energies (RsA =3.76 fm for 12C and 5.33 fm for 4~ at 1,370 MeV compared to 4.61fro and 6.45fm, respectively, around 140 MeV [7,8]). This indicates the increased surface transparency at higher energies which has been observed already at 700 MeV [4 I.…”

Different Methods for Pion-nucleus Optical Potential

“…The values of the deformation lengths for all collective states analyzed here are summarized in Table 2 and compared to those extracted from K + scattering [14] and to the corresponding ones previously extracted by others [15][16][17][18] . It is clear from [14][15][16][17][18] .…”

“…It is clear from [14][15][16][17][18] . It can be seen from Table 2 that the values of imaginary deformation lengths determined here using the 3α-particle model and Kisslinger local potential for 2 + and 3 -excited states in the 12C increase with increasing pion kinetic energy, except for the case of 180 MeV π¯ inelastic scattering of 3 -state in 12 C. This 180 MeV energy lies in the (3, 3) resonance region of pions.…”

“…The inelastic data [10] are well represented by the present Kisslinger calculations with χ 2 =1.82 for π + and 2.35 for π¯ and Laplacian potential calculations with χ 2 =4.28 for π + and 3.15 for π¯, when the first and second order parameters are included in both of potentials, while calculations based on the 3α-particle model fail to agree with data at forward angles for π + with χ 2 =9.13 and also give a poor fit with π¯ data with χ 2 =6.13. 1.12-1.97 [15] 1.02-1.41…”

“…1.07±0.05 [17] 1.5-1.21 [18] 0.65-1.23 [15] Reaction Figure 5 and 6 display the predictions of the inelastic scattering differential cross-sections of π¯ from 12 C nucleus excited to the lowest 2 + and 3 + states in 150, 180 and 260 MeV. The three forms for the optical potential models give reasonable agreement with inelastic scattering data of [9] , but the Kisslinger local potential predictions seem to be better at all energies considered in the present work with χ 2 ranging from 5.…”