Seagull and pion-in-flight currents in neutrino-induced 1N1N and 2N2N knockout

[Background] The neutrino-nucleus ($\nu A$) cross section is a major source of systematic uncertainty in neutrino-oscillation studies. A precise $\nu A$ scattering model, in which multinucleon effects are incorporated, is pivotal for an accurate interpretation of the data. [Purpose] In $\nu A$ interactions, meson-exchange currents (MECs) can induce two-nucleon ($2N$) knockout from the target nucleus, resulting in a two-particle two-hole (2p2h) final state. They also affect single nucleon ($1N$) knockout reactions, yielding a one-particle one-hole (1p1h) final state. Both channels affect the inclusive strength. We present a study of axial and vector, seagull and pion-in-flight currents in muon-neutrino induced $1N$ and $2N$ knockout reactions on $^{12}$C. [Method] Bound and emitted nucleons are described as Hartree-Fock wave functions. For the vector MECs, the standard expressions are used. For the axial current, three parameterizations are considered. The framework developed here allows for a treatment of MECs and short-range correlations (SRCs). [Results] Results are compared with electron-scattering data and with literature. The strengths of the seagull, pion-in-flight and axial currents are studied separately and double differential cross sections including MECs are compared with results including SRCs. A comparison with MiniBooNE and T2K data is presented. [Conclusions] In the 1p1h channel, the effects of the MECs tend to cancel each other, resulting in a small effect on the double differential cross section. $2N$ knockout processes provide a small contribution to the inclusive double differential cross section, ranging from the $2N$ knockout threshold into the dip region. A fair agreement with the MiniBooNE and T2K data is reached.Comment: 16 pages, 10 figure

Electron-neutrino scattering off nuclei from two different theoretical perspectives

We analyze charged-current electron-neutrino cross sections on Carbon. We consider two different theoretical approaches, on one hand the Continuum Random Phase Approximation (CRPA) which allows a description of giant resonances and quasielastic excitations, on the other hand the RPA-based calculations which are able to describe multinucleon emission and coherent and incoherent pion production as well as quasielastic excitations. We compare the two approaches in the genuine quasielastic channel, and find a satisfactory agreement between them at large energies while at low energies the collective giant resonances show up only in the CRPA approach. We also compare electron-neutrino cross sections with the corresponding muon-neutrino ones in order to investigate the impact of the different charged-lepton masses. Finally, restricting to the RPA-based approach we compare the sum of quasielastic, multinucleon emission, coherent and incoherent one-pion production cross sections (folded with the electron-neutrino T2K flux) with the charged-current inclusive electron-neutrino differential cross sections on Carbon measured by T2K. We find a good agreement with the data. The multinucleon component is needed in order to reproduce the T2K electron-neutrino inclusive cross sections

Impact of low-energy nuclear excitations on neutrino-nucleus scattering at MiniBooNE and T2K kinematics

[Background] Meticulous modeling of neutrino-nucleus interactions is essential to achieve the unprecedented precision goals of present and future accelerator-based neutrino-oscillation experiments. [Purpose] Confront our calculations of charged-current quasielastic cross section with the measurements of MiniBooNE and T2K, and to quantitatively investigate the role of nuclear-structure effects, in particular, low-energy nuclear excitations in forward muon scattering. [Method] The model takes the mean-field (MF) approach as the starting point, and solves Hartree-Fock (HF) equations using a Skyrme (SkE2) nucleon-nucleon interaction. Long-range nuclear correlations are taken into account by means of the continuum random-phase approximation (CRPA) framework. [Results] We present our calculations on flux-folded double differential, and flux-unfolded total cross sections off $^{12}$C and compare them with MiniBooNE and (off-axis) T2K measurements. We discuss the importance of low-energy nuclear excitations for the forward bins. [Conclusions] The CRPA predictions describe the gross features of the measured cross sections. They underpredict the data (more in the neutrino than in the antineutrino case) because of the absence of processes beyond pure quasielastic scattering in our model. At very forward muon scattering, low-energy nuclear excitations ($\omega <$ 50 MeV) account for nearly 50% of the flux-folded cross section.Comment: 8 pages, 9 figures. Version published in Physical Review

Nuclear Structure Physics in Coherent Elastic Neutrino-Nucleus Scattering

The prospects of extracting new physics signals in a coherent elastic neutrino-nucleus scattering (CE$\nu$NS) process are limited by the precision with which the underlying nuclear structure physics, embedded in the weak nuclear form factor, is known. We present microscopic nuclear structure physics calculations of charge and weak nuclear form factors and CE$\nu$NS cross sections on $^{12}$C, $^{16}$O, $^{40}$Ar, $^{56}$Fe and $^{208}$Pb nuclei. We obtain the proton and neutron densities, and charge and weak form factors by solving Hartree-Fock equations with a Skyrme (SkE2) nuclear potential. We validate our approach by comparing $^{208}$Pb and $^{40}$Ar charge form factor predictions with elastic electron scattering data. In view of the worldwide interest in liquid-argon based neutrino and dark matter experiments, we pay special attention to the $^{40}$Ar nucleus and make predictions for the $^{40}$Ar weak form factor and the CE$\nu$NS cross sections. Furthermore, we attempt to gauge the level of theoretical uncertainty pertaining to the description of the $^{40}$Ar form factor and CE$\nu$NS cross sections by comparing relative differences between recent microscopic nuclear theory and widely-used phenomenological form factor predictions. Future precision measurements of CE$\nu$NS will potentially help in constraining these nuclear structure details that will in turn improve prospects of extracting new physics.Comment: 12 pages, 14 figure

PPP1R8 (protein phosphatase 1, regulatory (inhibitor) subunit 8)

Review on PPP1R8 (protein phosphatase 1, regulatory (inhibitor) subunit 8), with data on DNA, on the protein encoded, and where the gene is implicated

Comparison of two corticosteroid regimens on brain volumetrics in patients with Duchenne muscular dystrophy

ObjectiveDuchenne muscular dystrophy (DMD) is a neuromuscular disorder in which many patients also have neurobehavioral problems. Corticosteroids, the primary pharmacological treatment for DMD, have been shown to affect brain morphology in other conditions, but data in DMD are lacking. This study aimed to investigate the impact of two corticosteroid regimens on brain volumetrics in DMD using magnetic resonance imaging (MRI).MethodsIn a cross-sectional, two-center study, T1-weighted MRI scans were obtained from three age-matched groups (9–18 years): DMD patients treated daily with deflazacort (DMDd, n = 20, scan site: Leuven), DMD patients treated intermittently with prednisone (DMDi, n = 20, scan site: Leiden), and healthy controls (n = 40, both scan sites). FSL was used to perform voxel-based morphometry analyses and to calculate intracranial, total brain, gray matter, white matter, and cerebrospinal fluid volumes. A MANCOVA was employed to compare global volumetrics between groups, with site as covariate.ResultsBoth patient groups displayed regional differences in gray matter volumes compared to the control group. The DMDd group showed a wider extent of brain regions affected and a greater difference overall. This was substantiated by the global volume quantification: the DMDd group, but not the DMDi group, showed significant differences in gray matter, white matter, and cerebrospinal fluid volumes compared to the control group, after correction for intracranial volume.InterpretationVolumetric differences in the brain are considered part of the DMD phenotype. This study suggests an additional impact of corticosteroid treatment showing a contrast between pronounced alterations seen in patients receiving daily corticosteroid treatment and more subtle differences in those treated intermittently.Neurological Motor Disorder