Comparing TWOFNR and FRESCO calculations for 56 Ni

Comparing TWOFNR and FRESCO calculations for 56 Ni transfer cross sections (p, d) Ø Zero-range and finite-range options Ø Consistency with increasing beam energy Ø Consistency with different potentials (d, 3 He) Ø Discontinuity with increasing energy in TWOFNR calculations with Daehnick deuteron potential [for (d, 3 He) reaction only]

56 Ni(p, d)

56 Ni(p, d) cross sections – Zero-range and Finite-range Chapel Hill 89 optical potential for p Johnson-Soper Adiabatic potential for d Same set of options • brush front end – produces input file for both calculations • did NOT include nonlocality • not an option for FRESCO • tried both ZR and FR (LEA) options Near peak, very little difference between the calculations Solid = TWOFNR Dashed = FRESCO 7 Nov

56 Ni(p, d) cross sections – increasing beam energy Chapel Hill 89 optical potential for p Johnson-Soper Adiabatic potential + CH 89 for d Little difference at peak with adiabatic pot. Differences at: • larger angles • higher energy Each color is a different beam energy (Me. V/u) Solid = TWOFNR Dashed = FRESCO 15 Nov

56 Ni(p, d) cross sections – different deuteron potential Chapel Hill 89 optical potential for p Daehnick Global optical potential for d Excellent agreement throughout the energy range using Daehnick deuteron potential Shape of cross section is much different than when using adiabatic potential Each color is a different beam energy (Me. V/u) Solid = TWOFNR Dashed = FRESCO 15 Nov

56 Ni(d, 3 He)

56 Ni(d, 3 He) cross sections – increasing energy for (d, 3 He) Daehnick Global optical potential for d Bechetti-Greenlees optical potential for 3 He Little difference at low E (red, black, green) Enormous differences above ~60 Me. V/u Related to Daehnick discontinuity ? [see later slides] Each color is a different beam energy (Me. V/u) Solid = TWOFNR Dashed = FRESCO 15 Nov

56 Ni(d, 3 He) cross sections – different deuteron potential Perey-Perey optical potential for d Bechetti-Greenlees optical potential for 3 He Excellent agreement throughout the energy range with Perey-Perey deuteron potential Each color is a different beam energy (Me. V/u) Solid = TWOFNR Dashed = FRESCO 23 Nov

56 Ni(d, 3 He) Daehnick discontinuity

56 Ni(d, 3 He) cross sections – Daehnick discontinuity Daehnick Global optical potential for d Bechetti-Greenlees optical potential for 3 He Smooth change in cross section with energy E<75 and E>76, Discontinuity at E~75. 85 Me. V Thick black lines are 60, 70, 80 Me. V/u Thin lines are 1 Me. V/u steps TWOFNR 17 Nov

56 Ni(d, 3 He) cross sections – no Daehnick discontinuity Daehnick Global optical potential for d Bechetti-Greenlees optical potential for 3 He Smooth change in cross section with energy over entire range Thick black lines are 60, 70, 80 Me. V/u Thin lines are 1 Me. V/u steps FRESCO 17 Nov

Future investigations with these codes (p, d) Ø Compare FRESCO calculations with exact finite range option (rather than LEA) – this is something TWOFNR doesn’t include Ø Run calcs with JLM potential for proton (d, 3 He) Ø Try to determine if Daehnick discontinuity in TWOFNR related to integration range, or possibly some other numerical effect Ø Implement GDP 08 potential in TWOFNR?