Measurements of the differential cross section and polarization in proton-proton scattering at about 143 MeV

Optimized Chiral Nucleon-Nucleon Interaction at Next-to-Next-to-Leading Order

“…However, excitation energies relative to the ground state converge somewhat better. Our results for the first 2 + state in 22,24 O and in 48 Ca are 2.3(3) MeV, 3.5(5) MeV and 4.8 (7) MeV, respectively. We estimate the uncertainty by varying Ω in the interval [16][17][18][19][20][21][22] MeV.…”

“…Value [3] with respect to the np and pp 1999 databases [23]. The values without the high-precision data sets [24] are marked by asterisks. The unusual precision of those 47 data points distorts the χ 2 /datum for this interval.…”

“…The complete description of nuclei at NNLO also requires 3NFs. We computed the first 2 + state in 22,24 O and in 48 Ca with the 3NF compatible with the NNLO opt interaction. The matrix elements of the 3NF are expensive computationally, and we must at present limit their calculation to three-body energies up to e 3max = 2n a + l a + 2n b + l b + 2n c + l c = 14.…”

“…We estimate the uncertainty by varying Ω in the interval [16][17][18][19][20][21][22] MeV. The results obtained by using NNLO opt N N interaction alone yields 2.5 MeV, 5.0 MeV, and 4.5 MeV in 22,24 O and 48 Ca, respectively. These preliminary results suggest that the 3NFs may not dramatically change the results that were obtained with the NNLO opt N N interaction alone.…”

“…Around energies of 144 MeV there exist two data sets of pp differential cross sections with a very high precision (0.5% error) [24] (47 data points). The total number of pp data in the energy interval 125-183 MeV is 343.…”