The nuclear response in the isoscalar channel

Abstract

The nuclear response is evaluated in the frame of the bosonic loop expansion in a purely nucleonic dynamical scheme, which seems to be reliable in handling those channels where a direct excitation of a ∆-resonance is not allowed. It is shown that the response strongly depends upon the effective interaction in the spin-transverse isovector channel. New experiments at CEBAF on parity-violating electron scattering could further constrain the form of the effective interaction.

The longitudinal and transverse responses in the inclusive electron scattering A functional approach

“…Having shortly revisited the experimental and theoretical situation, let us spend a few words about the philosophy underlying our approach [1,19].…”

“…No indications are available instead for q c T . Some possible choices are discussed in [19], but since the interaction in the ρ-channel dominates the responses, as we shall see below, we defer its description to the subsequent sections. The vertex function present in (5) is customarily assumed to be…”

“…9, together with the one we employed in ref. [19] (m ρ = 770 MeV , g ′ 0 = 0.5, q c,T = 1.4 GeV /c, C ρ = 2.2, Λ = 2.5 GeV /c). We remark, as already outlined in [19], that this effective interaction is qualitatively analogous to the one used by Oset and coworkers [33,46].…”

“…[19] (m ρ = 770 MeV , g ′ 0 = 0.5, q c,T = 1.4 GeV /c, C ρ = 2.2, Λ = 2.5 GeV /c). We remark, as already outlined in [19], that this effective interaction is qualitatively analogous to the one used by Oset and coworkers [33,46]. The main difference, which is now linked to a phenomenological outcome, is the point where the effective interaction changes sign, which is, in view of the quoted experimental data, set around 300 MeV /c.…”