arXiv subjects

R. Gran

Publications and source records attributed to R. Gran.

At least 19 recordsLinked to original sources

arXiv2026

Comparisons of triple-differential cross sections for quasielastic-like $\nu_\mu$-hydrocarbon interactions using $\langle E_\nu\rangle \sim$ 3~GeV versus $\sim$ 6~GeV beams in MINERvA

Neutrino charged-current quasielastic-like scattering, a reaction category extensively used in neutrino oscillation measurements, receives contributions from single nucleon knockout processes, multinucleon processes, and inelastic scattering with subsequent rescattering or absorption in the nucleus to produce only nucleons in the final state. In this article, comparisons are presented of the same measurement in two different wideband neutrino beams: one beam peaks near 3 GeV with few neutrinos above 6 GeV; the other peaks near 6 GeV with few neutrinos above 10 GeV. Comparisons of differential cross sections in muon and proton kinematics for these two exposures probe deviations from free-neutron scattering that arise from the processes involving the nuclear medium, and provide a test of neutrino interaction models used to infer neutrino energies in oscillation experiments. Discrepancies are observed between the data and predictions that point to overestimates of the final state interactions of both protons and charged pions in quasielastic-like events.

hep-ex↗

arXiv2026

High Statistics Measurements of $\nu_{\mu}$ Charged-Current Single $\pi^{+}$ Production with Zero Pion Kinetic Energy Threshold in MINERvA

This Letter presents measurements of single-differential cross sections of $\nu_{\mu}$-induced charged-current 1 $\pi^{+}$ production on scintillator using the MINERvA detector at Fermilab. These measurements use traditional track-based pion reconstruction as well as pions identified solely via Michel electron decays, allowing measurement of kinetic energies from 0 to 350 MeV. In total, 91,843 events were selected with $W_{exp}$ $<$ 1.4 GeV/c. Differential cross sections as a function of pion and muon kinematic variables are presented and compared with the predictions of several neutrino event generators. Overall, modern pion production models tend to agree with data at the ends of the kinematic regions probed, but are discrepant with the main regions of the phase space probed by up to 15% in muon observables and up to 20% in pion observables. No model describes any of the variables well, and this result highlights model areas that require improvement for the next generation of neutrino oscillation experiments.

hep-ex↗

arXiv2026

Boosted decision tree reweighting of simulated neutrino interactions for $O(1)$ GeV neutrino cross section measurements

This paper illustrates a generic method for multi-dimensional reweighting of $O(1)$ GeV neutrino interaction Monte Carlo samples. The reweighting is based on a Boosted Decision Tree algorithm trained on high-dimensional space in detector final-state observables. This enables one generator's events to be reweighted so that its reconstructed particle content and kinematics distributions, as well as detector efficiency, match those of a target model. The approach establishes an efficient way to reuse legacy Monte Carlo data, avoiding re-generation. As an example, we test its use in a measurement of transverse kinematic imbalance of the $μ^-$ and proton in charged-current quasielastic like $ν_μ$ events from the MINERvA experiment.

hep-ex↗

arXiv2026

Measurement of Inclusive Charged-Current $\barν_μ$ Scattering on C, CH, Fe, and Pb at $\langle E_{\barν}\rangle \sim$ 6 GeV with MINERvA

We report MINERvA's first measurement of inclusive charged-current $\barν_μ$ cross sections on carbon, hydrocarbon, iron, and lead, and their ratios to the cross section on hydrocarbon, as functions of the antimuon transverse momentum, $p_{\mathrm{T}}$. Using a wide-band $\barν_μ$ beam with mean energy $\sim 6~\text{GeV}$, these measurements probe all interaction modes, including the transition from resonance production to deep-inelastic scattering. The total uncertainties are typically $5-10\%$ for the absolute cross sections and $2-5\%$ for the ratios. Comparisons with multiple neutrino interaction models reveal significant discrepancies in the $p_{\mathrm{T}}$ dependence, particularly for heavier nuclei. The disagreements are most pronounced at low $p_{\mathrm{T}}$ but extend across the full $p_{\mathrm{T}}$ range, indicating missing or mis-modelled nuclear effects.

hep-ex↗

arXiv2026

Nuclear binding energy and transverse momentum imbalance in neutrino-nucleus reactions

We have measured new observables based on the final state kinematic imbalances in the mesonless production of $ν_μ+A\rightarrowμ^-+p+X$ in the $\text{MINER}ν\text{A}$ tracker. Components of the muon-proton momentum imbalances parallel ($δp_\mathrm{Ty}$) and perpendicular($δp_\mathrm{Tx}$) to the momentum transfer in the transverse plane are found to be sensitive to the nuclear effects such as Fermi motion, binding energy and non-QE contributions. The QE peak location in $δp_\mathrm{Ty}$ is particularly sensitive to the binding energy. Differential cross sections are compared to predictions from different neutrino interaction models. The Fermi gas models presented in this study cannot simultaneously describe features such as QE peak location, width and the non-QE events contributing to the signal process. Correcting the GENIE's binding energy implementation according to theory causes better agreement with data. Hints of proton left-right asymmetry are observed in $δp_\mathrm{Tx}$. Better modeling of the binding energy can reduce bias in neutrino energy reconstruction and these observables can be applied in current and future experiments to better constrain nuclear effects.

hep-ex↗

arXiv2025

The Nucleon Axial Form Factor from Elementary Target Data

Precise neutrino-nucleon amplitudes are essential ingredients for predicting neutrino event rates in current and upcoming long-baseline neutrino oscillation experiments. A common neutrino interaction with a low reaction threshold and with most of the energy carried by two final state particles is quasielastic scattering, for which the nucleon axial form factor, $F_{A}(Q^{2})$, is a dominant source of uncertainty. Improvements to the nucleon axial form factor rely on neutrino scattering data with elementary targets to reduce or eliminate the need for nuclear modeling systematics. This work examines constraints on the nucleon axial form factor that can be achieved from datasets of neutrino scattering on deuterium targets, Lattice QCD predictions, and from the recent hydrogen target data from the MINERvA Collaboration. Significant tension is found between hydrogen and deuterium target data, suggesting that extractions from deuterium underestimate both the central value and uncertainty of the form factor. Parameterizations for and uncertainties of the nucleon axial form factor using the $z$ expansion are provided.

hep-ex↗

arXiv2025

Readout electronics for low occupancy High-Pressure Gas TPCs

HPgTPCs have benefits such as low energy threshold, magnetisability, and 4$π$ acceptance, making them ideal for neutrino experiments such as DUNE. We present the design of an FPGA-based solution optimised for ND-GAr, which is part of the Phase-II more capable near detector for DUNE. These electronics reduce the cost significantly compared to using collider readout electronics which are typically designed for much higher occupancy and therefore, for example, need much larger numbers of FPGAs and power per channel. We demonstrate the performance of our electronics with the TOAD at Fermilab in the US at a range of pressures and gas mixtures up to 4.5barA, reading out ~10000 channels from a multi-wire proportional chamber. The operation took place between April and July of 2024. We measure the noise characteristics of the system to be sufficiently low and we identify sources of noise that can be further mitigated in the next iteration. We also note that the cooling scheme used in the test requires improvement before full-scale deployment. Despite these necessary improvements, we show that the system can fulfil the needs of a HPgTPC for a fraction of the price of collider readout electronics.

physics.ins-det↗

arXiv2025

Measurement of the A dependence of the muon neutrino charged-current quasielastic-like cross section as a function of muon and proton kinematics at $<$E$_ν>\sim$6 GeV

The first simultaneous measurements of the $ν_μ$ quasielastic-like cross section on C, CH, H$_2$0, Fe, and Pb targets as a function of kinematic imbalance variables in the plane transverse to the incoming neutrino direction are presented. These variables combine the muon and proton information to provide a new way to disentangle the effects of the nucleus in quasielastic-like processes. The data were obtained using a wide-band $ν_μ$ beam with $<$E$_ν>\sim$6 GeV. Cross-section ratios of the different target materials to CH are also shown. These measurements are used to explore the nature of the cross-section $A$-scaling, as well as initial and final state interaction effects. Comparisons are made to predictions from a number of commonly used neutrino Monte Carlo event generators. The range of predictions of the different models tends to cover the data but the degree and consistency of the agreement suffers in regions, and on higher $A$ targets, where the final state interactions are expected to be more pronounced.

hep-ex↗

arXiv2025

Measurement of charged-current $ν_μ$ and $\barν_μ$ cross sections on hydrocarbon in a shallow inelastic scattering region

This MINERvA analysis is the first neutrino and antineutrino study of a shallow inelastic scattering region, which is the transition region between resonant production and deep inelastic scattering processes. This transition is explicitly included in this study by expanding the scope of shallow inelastic scattering to include not only the mainly lower-$Q^2$ nonresonant pion production but also the kinematic region where pion production off quarks within the nucleon becomes significant with $Q^2$ below the onset of the deep-inelastic scattering region defined in this analysis. To reduce the resonance background the kinematic region 1.5 $<$ $W$ $<$ 2 GeV/$c^2$ was chosen. In addition to the inclusive differential cross section measurements, to emphasize SIS interactions off quarks within the nucleon a sample with $Q^2$ $\geq$ 1 GeV/$c^2$ was also analyzed. The measurements of one-dimensional cross sections at $\left\langle E_ν\right\rangle \sim 6$ GeV on hydrocarbon of $Q^2$, Bjorken x and muon momentum variables are compared with modified predictions from the GENIE 2 neutrino generator as well as predictions of other neutrino simulators GiBUU, NEUT, NuWro and an alternative GENIE 3 version. Significant discrepancies both in shape and magnitude between measurements and neutrino simulator predictions of all variables have been observed.

hep-ex↗

arXiv2025

Investigation of Medium Modifications to $^{12}$C Structure Functions in the Resonance Region

We present results from a high precision experimental study of the nuclear modification of the longitudinal ($F_L$) to transverse ($F_1$) structure function ratio for bound nucleons in the resonance region. The inclusive electron scattering cross sections were measured in Jefferson Lab Experimental Hall C on carbon and deuterium nuclei for a large range of kinematics, allowing for separations of the longitudinal and transverse structure functions to be performed at a range of four-momentum transfer values $0.5 \le Q^2 \le$ 3.75 GeV$^2$. In contrast to the significant body of measurements of the nuclear modification of the $F_2$ structure function in the deep inelastic scattering region, there is very little on $F_L$ and $R = F_L / 2xF_1$ in the region of the nucleon resonances. In this paper we present measurements of the nuclear effect on $R$ for $^{12}$C ($R_C$) relative to deuterium ($R_D$). These results indicate regions in which in $R_C>R_D$, requiring that the nuclear modifications be different in all three structure functions, $F_2$, $F_1$ and $F_L$.

nucl-ex↗

arXiv2024

Probing nuclear effects with neutrino-induced charged-current neutral pion production

We study neutrino-induced charged-current (CC) $π^0$ production on carbon nuclei using events with fully imaged final-state proton-$π^0$ systems. Novel use of final-state correlations based on transverse kinematic imbalance enable the first measurements of the struck nucleon's Fermi motion, of the intranuclear momentum transfer (IMT) dynamics, and of the final-state hadronic momentum configuration in neutrino pion production. Event distributions are presented for i) the momenta of neutrino-struck neutrons below the Fermi surface, ii) the direction of missing transverse momentum characterizing the strength of IMT, and iii) proton-pion momentum imbalance with respect to the lepton scattering plane. The observed Fermi motion and IMT strength are compared to the previous MINERvA measurement of neutrino CC quasielastic-like production. The measured shapes and absolute rates of these distributions, as well as the cross-section asymmetries show tensions with predictions from current neutrino generator models.

hep-ex↗

arXiv2024

Measurement of Electron Neutrino and Antineutrino Cross Sections at Low Momentum Transfer

Accelerator based neutrino oscillation experiments seek to measure the relative number of electron and muon neutrinos and antineutrinos at different $L/E$ values. However high statistics studies of neutrino interactions are almost exclusively measured using muon neutrinos and antineutrinos since the dominant flavor of neutrinos produced by accelerator based beams are of the muon type. This work reports new measurements of electron neutrino and antineutrino interactions in hydrocarbon, obtained by strongly suppressing backgrounds initiated by muon flavor neutrinos and antineutrinos. Double differential cross sections as a function of visible energy transfer, $E_\text{avail}$, and transverse momentum transfer, $p_T$, or three momentum transfer, $q_3$ are presented.

hep-ex↗

arXiv2023

Measurement of the Multi-Neutron $\barν_μ$ Charged Current Differential Cross Section at Low Available Energy on Hydrocarbon

Neutron production in antineutrino interactions can lead to bias in energy reconstruction in neutrino oscillation experiments, but these interactions have rarely been studied. MINERvA previously studied neutron production at an average antineutrino energy of ~3 GeV in 2016 and found deficiencies in leading models. In this paper, the MINERvA 6 GeV average antineutrino energy data set is shown to have similar disagreements. A measurement of the cross section for an antineutrino to produce two or more neutrons and have low visible energy is presented as an experiment-independent way to explore neutron production modeling. This cross section disagrees with several leading models' predictions. Neutron modeling techniques from nuclear physics are used to quantify neutron detection uncertainties on this result.

hep-ex↗

arXiv2023

Simultaneous measurement of muon neutrino $ν_μ$ charged-current single $π^+$ production in CH, C, H$_2$O, Fe, and Pb targets in MINERvA

Neutrino-induced charged-current single $π^+$ production in the $Δ(1232)$ resonance region is of considerable interest to accelerator-based neutrino oscillation experiments. In this work, high statistics differential cross sections are reported for the semi-exclusive reaction $ν_μA \to μ^- π^+ +$ nucleon(s) on scintillator, carbon, water, iron, and lead targets recorded by MINERvA using a wide-band $ν_μ$ beam with $\left< E_ν\right> \approx 6$~GeV. Suppression of the cross section at low $Q^2$ and enhancement of low $T_π$ are observed in both light and heavy nuclear targets compared to phenomenological models used in current neutrino interaction generators. The cross-section ratios for iron and lead compared to CH across the kinematic variables probed are 0.8 and 0.5 respectively, a scaling which is also not predicted by current generators.

hep-ex↗

arXiv2023

Neutrino-induced coherent $π^{+}$ production in C, CH, Fe and Pb at $\langle E_ν\rangle \sim 6$ GeV

MINERvA has measured the $ν_μ$-induced coherent $π^{+}$ cross section simultaneously in hydrocarbon (CH), graphite (C), iron (Fe) and lead (Pb) targets using neutrinos from 2 to 20 GeV. The measurements exceed the predictions of the Rein-Sehgal and Berger-Sehgal PCAC based models at multi-GeV $ν_μ$ energies and at produced $π^{+}$ energies and angles, $E_π>1$ GeV and $θ_π<10^{\circ}$. Measurements of the cross-section ratios of Fe and Pb relative to CH reveal the effective $A$-scaling to increase from an approximate $A^{1/3}$ scaling at few GeV to an $A^{2/3}$ scaling for $E_ν>10$ GeV.

hep-ex↗

arXiv2023

High-Statistics Measurement of Antineutrino Quasielastic-like scattering at $E_ν\sim$ 6~GeV on a Hydrocarbon Target

We present measurements of the cross section for anti-neutrino charged-current quasielastic-like scattering on hydrocarbon using the medium energy (ME) NuMI wide-band neutrino beam peaking at $ \sim 6$ GeV. The cross section measurements are presented as a function of the longitudinal momentum ($p_{||}$) and transverse momentum ($p_{T}$) of the final state muon. This work complements our previously reported high statistics measurement in the neutrino channel and extends the previous anti-neutrino measurement made in the low energy (LE) beam at neutrino energy($ $) $\sim$ 3.5 GeV to $p_{T}$ of 2.5 GeV/c. Current theoretical models do not completely describe the data in this previously unexplored high $p_{T}$ region. The single differential cross section as a function of four momentum transfer ($Q^{2}_{QE}$) now extends to 4 GeV$^2$ with high statistics. The cross section as a function of $Q^{2}_{QE}$ shows that the tuned simulations developed by the MINERvA collaboration that agreed well with the low energy beam measurements do not agree as well with the medium energy beam measurements. Newer neutrino interaction models such as the GENIE 3 tunes are better able to simulate the high $Q^{2}_{QE}$.

hep-ex↗

arXiv2023

Simultaneous measurement of muon neutrino quasielastic-like cross sections on CH, C, water, Fe, and Pb as a function of muon kinematics at MINERvA

This paper presents the first simultaneous measurement of the quasielastic-like neutrino-nucleus cross sections on C, water, Fe, Pb and scintillator (hydrocarbon or CH) as a function of longitudinal and transverse muon momentum. The ratio of cross sections per nucleon between Pb and CH is always above unity and has a characteristic shape as a function of transverse muon momentum that evolves slowly as a function of longitudinal muon momentum. The ratio is constant versus longitudinal momentum within uncertainties above a longitudinal momentum of 4.5GeV/c. The cross section ratios to CH for C, water, and Fe remain roughly constant with increasing longitudinal momentum, and the ratios between water or C to CH do not have any significant deviation from unity. Both the overall cross section level and the shape for Pb and Fe as a function of transverse muon momentum are not reproduced by current neutrino event generators. These measurements provide a direct test of nuclear effects in quasielastic-like interactions, which are major contributors to long-baseline neutrino oscillation data samples.

hep-ex↗

arXiv2022

Neutron detection and application with a novel 3D-projection scintillator tracker in the future long-baseline neutrino oscillation experiments

Neutrino oscillation experiments require a precise measurement of the neutrino energy. However, the kinematic detection of the final-state neutron in the neutrino interaction is missing in current neutrino oscillation experiments. The missing neutron kinematic detection results in a feed-down of the detected neutrino energy compared to the true neutrino energy. A novel 3D\textcolor{black}{-}projection scintillator tracker, which consists of roughly ten million active cubes covered with an optical reflector, is capable of measuring the neutron kinetic energy and direction on an event-by-event basis using the time-of-flight technique thanks to the fast timing, fine granularity, and high light yield. The $\barν_μ$ interactions tend to produce neutrons in the final state. By inferring the neutron kinetic energy, the $\barν_μ$ energy can be reconstructed better, allowing a tighter incoming neutrino flux constraint. This paper shows the detector's ability to reconstruct neutron kinetic energy and the $\barν_μ$ flux constraint achieved by selecting the charged-current interactions without mesons or protons in the final state.

hep-ex↗