Extensions of superscaling from relativistic mean field theory: The SuSAv2 model

Abstract

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.

Parity violation in quasielastic electron-nucleus scattering within the relativistic impulse approximation

“…Not only does the function show an important asymmetry, with a long tail extended to high transferred energies, in accordance with data, but also the scaling functions corresponding to the longitudinal and transverse channels present differences, the T response being larger by ∼ 20%. This result, that is absent in most other theoretical approaches, seems to be supported by the analysis of data presented in [56,72].…”

“…The superscaling approach has been studied in detail in the past [12,35,[59][60][61][62] and its predictions have been extended to the analysis of neutrino-nucleus scattering processes [11,56,[63][64][65][66][67][68][69][70][71]. Moreover, scaling properties have also been analyzed within the context of different models, in particular, the RPWIA and the RMF-FSI approaches considered in this work.…”

“…All results in this section have been computed using the RMF-FSI model, that is, FSI are incorporated in the general formalism making use of the same relativistic, scalar and vector, potentials used for the bound nucleon states. This model has been widely tested in the case of the purely EM interaction comparing its prediction with a large body of (e, e ′ ) data (see [11,12,56]). In Fig.…”

Measurement of theνμcharged-current quasielastic cross section on carbon with the ND280 detector at T2K

“…Such additional processes not only contribute to the measured total cross section but also can affect the neutrino energy reconstruction. These new models have had success in describing MiniBooNE CCQE data [13][14][15][16][17] and T2K CC data [18][19][20][21][22]. However, models that simultaneously describe all data sets from low and high energy experiments remain elusive [17,[20][21][22][23].…”

Meson-exchange currents and quasielastic predictions for neutrino-nucleus scattering

“…This is the basis of the SuSA model [1], which exploits the scaling and superscaling properties exhibited by electron scattering data in order to predict neutrino-nucleus observables. In its more recent version, SuSAv2 [2], the model also takes into account the behavior of the responses provided by the Relativistic Mean Field (RMF): in particluar, the natural enhancement of the transverse electromagnetic response provided by RMF, a genuine dynamical relativistic effect, is incorporated in the SuSAv2 approach. However, while the RMF approach works properly at low to intermediate values of the momentum transfer q, where the effects linked to the treatment of the final-state interactions (FSI) are significant, it fails at higher q due to the strong energy-independent scalar and vector RMF potentials, whose effects should instead become less and less important with increasing momentum transfer.…”