Elastic and inelastic scattering of 0.8 GeV protons fromAr40

Dirac coupled channel analyses of proton inelastic scattering from the 40Ar nucleus

“…The surface-peaked phenomena observed for most of the s-d shell deformed nuclei [7,[10][11][12][13] are not observed at the effective central potentials when 40 Ar nucleus is considered. The strength of the real effective central potential of the Dirac approach turns out to be large, about -130 MeV at the center of the nucleus, compared to that of the nonrelativistic Schrödinger approach, which is about 4.0MeV [14]. The real parts of the effective central and spin-orbit potentials turn out to have negative values as in the cases of the other deformed nuclei [12,13], while those of the nonrelativistic calculations states, and the results are compared with those obtained by the calculation where only the ground and one excited states are coupled.…”

“…In Fig. 2, the Dirac effective central and spin-orbit potentials for 40 Ar are compared with those of the nonrelativistic calculations [14]. We should note that one of the merits of using the relativistic approach based on the Dirac equation instead of using the nonrelativistic approach based on the Schrödinger equation is that the spin-orbit potential appears naturally in the Dirac approach when the Dirac equation is reduced to a Schrödinger-like secondorder differential equation, whereas the spin-orbit potential must be inserted by hand in the nonrelativistic Schrödinger approach.…”

“…Reproducing hadron scattering experimental data of excited 0 + levels is known to be notoriously difficult because the form factors of λ = 0 transitions, the assignment of the excited 0 + state to a band structure, the reduced matrix elements, and the relative phases for all the multipolarities of the different transitions are not well known [15]. by using the nonrelativistic DWBA calculations [14] using the same Woods-Saxon shapes for the geometries of the optical potentials, even though the theoretical bases are quite different.…”

“…So far only the distorted wave Born approximation (DWBA) calculation using phenomenological optical potentials in nonrelativistic formalism neglecting the coupled channel effects, or the nonrelativistic coupled channel calculation at low energy has been done to analyze the inelastic scatterings of proton from 40 Ar nucleus [14,15]. A rotational collective model is used for the transition optical potentials to accommodate the collective motion of excited deformed nuclei considering the low lying excited states of the rotational bands [5].…”

Inclusive and exclusive electron scattering data analysis from Jefferson Lab experiment E12-14-012

“…A test of this ability is presented in Fig. 6.8, where the 40 Ar(p, p ′ ) cross section calculated at 0.8 GeV with the three OPs is compared to the corresponding experimental cross section obtained using the HRS of the Los Alamos Meson Physics Facility [171]. The results of the three OPs largely overlap, and their agreement with the experimental cross section, although not perfect, is more than reasonable, in particular if we consider that it has not been obtained from a fit to the data.…”