Using electron scattering superscaling to predict charge-changing neutrino cross sections in nuclei

Abstract

Superscaling analyses of few-GeV inclusive electron scattering from nuclei are extended to include not only quasielastic processes, but also the region where excitation dominates. With reasonable assumptions about the basic nuclear scaling function extracted from data and information from other studies of the relative roles played by correlation and meson-exchange-current effects, it is shown that the residual strength in the resonance region can be accounted for through an extended scaling analysis. One observes scaling upon assuming that the elementary cross section by which one divides the residual to obtain a new scaling function is dominated by the N → transition and employing a new scaling variable suited to the resonance region. This yields a good representation of the electromagnetic response in both the quasielastic and regions. The scaling approach is then inverted and predictions are made for charge-changing neutrino reactions at energies of a few GeV, with focus placed on nuclei that are relevant to neutrino oscillation measurements. For this, a relativistic treatment of the required weak interaction vector and axial-vector currents for both quasielastic and -excitation processes is presented.

Scaling and isospin effects in quasielastic lepton–nucleus scattering in the relativistic mean field approach

“…Within the context of our model this outcome reinforces the validity of the general assumption implied by SuSA [19], i.e., the use of the phenomenological scaling function (extracted from the analysis of longitudinal QE electron scattering data) to predict CC neutrino-nucleus cross sections. However, it is also striking that f (ψ ) for ν μ and ν μ reactions, which are totally dominated by the purely transverse (T , T ) channels, coincides with the f L function of (e, e ) instead of f T , in contrast to what one might expect.…”

“…The validity of the superscaling hypothesis, i.e., the existence of a universal scaling function in electroweak processes, constitutes an essential result which is supported by various theoretical studies [6][7][8]10] and gave rise to recent applications to neutrino studies [20,21]. The universal character of the scaling function is the basis of the SuperScaling Analysis (SuSA) introduced in [19]. Within SuSA, the experimental superscaling function extracted from the analysis of (e, e ) world data is used to reconstruct CC neutrino-nucleus cross sections.…”

“…One important application of superscaling has been suggested in [19] within the context of making realistic predictions for charge-changing (CC) neutrino-nucleus differential cross sections which, for example, are of interest in neutrino oscillation experiments. The validity of the superscaling hypothesis, i.e., the existence of a universal scaling function in electroweak processes, constitutes an essential result which is supported by various theoretical studies [6][7][8]10] and gave rise to recent applications to neutrino studies [20,21].…”

“…The longitudinal contribution to inclusive CC neutrino-nucleus scattering is negligible and therefore is not shown. The usual relativistic single-nucleon expression for the charged-current operator [14,19] has been employed. From results in Fig.…”

Nuclear effects in (anti)neutrino charge-current quasielastic scattering at MINER νA kinematics

“…Both have been extensively tested against existing QE electron scattering data over a wide energy range. The detailed description of these models can be found in our previous work (see, e.g., [14] and [15][16][17]). Here we just summarize their main features.…”