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.

Future high-precision neutrino interaction experiments are needed to extend the current program of GeV-scale neutrino interactions and should include:1. A feasibility study of a high-statistics hydrogen or deuterium scattering experiment to supplement the currently poorly known (anti)neutrino-nucleon cross sections.2. The need for (anti)neutrino Ar scattering data in the energy range relevant for the DUNE experiment.3. The possibility of muon-based neutrino beams providing extremely accurate knowledge of the neutrino flux and an intense electron neutrino beam.• Current and future long-and short-baseline neutrino oscillation programs should evaluate and articulate what additional neutrino-nucleus interaction data is required to meet their ambitious goals and support experiments that provide this data.In addition to these general challenges facing the community, there are more specific concerns for particular topics and interaction channels. These are summarized below in the form of observations, problem description or recommendations. For a deeper insight, the reader is encouraged to consult the subsequent sections of this paper.

Superscaling of the quasielastic cross section in charged-current neutrino-nucleus reactions at energies of a few GeV is investigated within the framework of the relativistic impulse approximation. Several approaches are used to describe final-state interactions and comparisons are made with the plane-wave approximation. Superscaling is very successful in all cases. The scaling function obtained using a relativistic mean field for the final states shows an asymmetric shape with a long tail extending towards positive values of the scaling variable, in excellent agreement with the behavior presented by the experimental scaling function. DOI: 10.1103/PhysRevLett.95.252502 PACS numbers: 25.30.Pt, 13.15.+g, 24.10.Jv In the context of inclusive quasielastic (QE) electron scattering at intermediate to high energies, the concepts of scaling [1] and superscaling [2] have been explored in previous work [3,4], where an exhaustive analysis of the e; e 0 world data demonstrated the quality of the scaling behavior. Scaling of the first kind (no dependence on the momentum transfer) is reasonably well respected at excitation energies below the QE peak, whereas scaling of the second kind (no dependence on the nuclear species) is excellent in the same region. The simultaneous occurrence of both kinds of scaling is called superscaling. At energies above the QE peak both scaling of the first and, to a lesser extent, of the second kind are shown to be violated because of important contributions introduced by effects beyond the impulse approximation, namely, inelastic scattering [5] together with correlations and meson exchange currents in both the 1p-1h and 2p-2h sectors [6,7].The scaling analysis of e; e 0 data has recently been extended through the QE peak into the region [8]. Of relevance to the present work we note that the high-energy inclusive electron scattering cross section is well represented up to the peak using the scaling ideas, importantly, with an asymmetric QE scaling function. In that study the scaling approach was also used to predict nuclear ; cross sections, based on the assumption of a universal scaling function, valid for both electron and neutrino scattering at corresponding kinematics.In this Letter we investigate the QE scaling properties of charged-current (CC) neutrino-nucleus scattering within the context of the relativistic impulse approximation (RIA). After verifying that various RIA models do superscale, we compare the associated scaling functions with the e; e 0 phenomenological one referred to above. This allows a check on the consistency of the universality assumption and on the capabilities of different models to yield the required properties of the experimental scaling function, specifically, its asymmetric form.Here we follow the general procedure of scaling and superscaling studies, namely, we first construct inclusive cross sections within a model and then obtain scaling functions by dividing them by the relevant single-nucleon cross sections weighted by the corresponding proton and neutron...

We present a systematic analysis of the quasielastic scaling functions computed within the Relativistic Mean Field (RMF) Theory and we propose an extension of the SuperScaling Approach (SuSA) model based on these results. The main aim of this work is to develop a realistic and accurate phenomenological model (SuSAv2), which incorporates the different RMF effects in the longitudinal and transverse nuclear responses, as well as in the isovector and isoscalar channels. This provides a complete set of reference scaling functions to describe in a consistent way both (e, e ′ ) processes and the neutrino/antineutrino-nucleus reactions in the quasielastic region. A comparison of the model predictions with electron and neutrino scattering data is presented.

The so-called semirelativistic expansion of the weakly charged current in powers of the initial nucleon momentum is performed to describe charge-changing, quasielastic neutrino reactions (ν µ , µ − ) at intermediate energies. The quality of the expansion is tested by comparing it with the relativistic Fermi gas model using several choices of kinematics of interest for ongoing neutrino oscillation experiments. The new current is then implemented in a continuum shell model together with relativistic kinematics to investigate the scaling properties of (e, e ) and (ν µ , µ − ) cross sections.

We present a detailed study of charged-current (CC) neutrino-nucleus reactions in a fully relativistic framework and comparisons with recent experiments spanning an energy range from hundreds of MeV up to 100 GeV within the SuperScaling Approach, which is based on the analysis of electronnucleus scattering data and has been recently improved with the inclusion of Relativistic Mean Field theory effects. We also evaluate and discuss the impact of two-particle two-hole meson-exchange currents (2p-2h MEC) on neutrino-nucleus interactions through the analysis of two-particle two-hole axial and vector contributions to weak response functions in a fully relativistic Fermi gas. The results show a fairly good agreement with experimental data over the whole range of neutrino energies.

We present our recent progress on the relativistic modeling of electron-nucleus reactions and compare our predictions with inclusive 12 C (e, e ′ ) experimental data in a wide kinematical region. The model, originally based on the superscaling phenomenon shown by electron-nucleus scattering data, has recently been improved through the inclusion of Relativistic Mean Field theory effects that take into account the enhancement of the quasielastic transverse scaling function compared with its longitudinal counterpart. In this work we extend the model to include the complete inelastic spectrum -resonant, non-resonant and deep inelastic scattering (DIS). We also discuss the impact of meson-exchange currents (MEC) through the analysis of two-particle two-hole contributions to electromagnetic response functions evaluated within the framework of the relativistic Fermi gas, considering for the first time not only the transverse but also the longitudinal channel. The results show quite good agreement with data over the whole range of energy transfer, including the dip region between the quasielastic peak and the ∆ resonance.

We evaluate the quasielastic double differential neutrino cross sections obtained in a phenomenological model based on the superscaling behavior of electron scattering data. We compare our results with the recent experimental data for neutrinos of MiniBooNE and estimate the contribution of the vector meson-exchange currents in the 2p-2h sector.DGI FIS2008-01143 y FIS2008-04189INFN–Ministerio de Educación y Ciencia FPA2008-03770-E-INFN y ACI2009-1053Spanish Consolider-Ingenio 2000 programmed CPAN CSD2007-00042U.S. Department of Energy DE-FC02-94ER4081