arXiv subjects

M. Kordosky

Publications and source records attributed to M. Kordosky.

At least 55 records · Page 3Linked to original sources

arXiv2019

Tuning the GENIE Pion Production Model with MINERvA Data

Faced with unresolved tensions between neutrino interaction measurements at few-GeV neutrino energies, current experiments are forced to accept large systematic uncertainties to cover discrepancies between their data and model predictions. In this paper, the widely used pion production model in GENIE is compared to four MINERvA charged current pion production measurements using NUISANCE. Tunings, ie, adjustments of model parameters, to help match GENIE to MINERvA and older bubble chamber data are presented here. We find that scattering off nuclear targets as measured in MINERvA is not in good agreement with scattering off nucleon (hydrogen or deuterium) targets in the bubble chamber data. An additional ad hoc correction for the low-$Q^2$ region, where collective effects are expected to be large, is also presented. While these tunings and corrections improve the agreement of GENIE with the data, the modeling is imperfect. The development of these tunings within the NUISANCE frameworkallows for straightforward extensions to other neutrino event generators and models, and allows omitting and including new data sets as they become available.

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arXiv2019

Measurement of $ν_μ$ charged-current single $π^{0}$ production on hydrocarbon in the few-GeV region using MINERvA

The semi-exclusive channel $ν_μ+\textrm{CH}\rightarrowμ^{-}π^{0}+\textrm{nucleon(s)}$ is analyzed using MINERvA exposed to the low-energy NuMI $ν_μ$ beam with spectral peak at $E_ν \simeq 3$ GeV. Differential cross sections for muon momentum and production angle, $π^{0}$ kinetic energy and production angle, and for squared four-momentum transfer are reported, and the cross section $σ(E_ν)$ is obtained over the range 1.5 GeV $\leq E_ν <$ 20 GeV. Results are compared to GENIE and NuWro predictions and to published MINERvA cross sections for $ν_μ\textrm{-CC}(π^{+})$ and $\barν_μ\textrm{-CC}(π^{0})$. Disagreements between data and simulation are observed at very low and relatively high values for muon angle and for $Q^2$ that may reflect shortfalls in modeling of interactions on carbon. For $π^{0}$ kinematic distributions however, the data are consistent with the simulation and provide support for generator treatments of pion intranuclear scattering. Using signal-event subsamples that have reconstructed protons as well as $π^{0}$ mesons, the $pπ^{0}$ invariant mass distribution is obtained, and the decay polar and azimuthal angle distributions in the rest frame of the $pπ^{0}$ system are measured in the region of $Δ(1232)^+$ production, $W < 1.4$ GeV.

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arXiv2019

Neutron measurements from anti-neutrino hydrocarbon reactions

Charged-current anti-neutrino interactions on hydrocarbon scintillator in the MINERvA detector are used to study activity from their final-state neutrons. To ensure that most of the neutrons are from the primary interaction, rather than hadronic reinteractions in the detector, the sample is limited to momentum transfers below 0.8 GeV/c. From 16,129 interactions, 15,246 neutral particle candidates are observed. The reference simulation predicts 64\% of these candidates are due to neutrons from the anti-neutrino interaction directly, but also overpredicts the number of candidates by 15\% overall, which is beyond the standard uncertainty estimates for models of neutrino interactions and neutron propagation in the detector. Using the measured distributions for energy deposition, time of flight, position, and speed, we explore the sensitivity to the details those two aspects of the models. We also use multiplicity distributions to evaluate the presence of a two-nucleon knockout process. These results provide critical new information toward a complete description of the hadronic final state of neutrino interactions, which is vital to neutrino oscillation experiments.

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arXiv2019

Identification of nuclear effects in neutrino-carbon interactions at low three-momentum transfer

Two different nuclear-medium effects are isolated using a low three-momentum transfer subsample of neutrino-carbon scattering data from the MINERvA neutrino experiment. The observed hadronic energy in charged-current $ν_μ$ interactions is combined with muon kinematics to permit separation of the quasielastic and $Δ$(1232) resonance processes. First, we observe a small cross section at very low energy transfer that matches the expected screening effect of long-range nucleon correlations. Second, additions to the event rate in the kinematic region between the quasielastic and $Δ$ resonance processes are needed to describe the data. The data in this kinematic region also has an enhanced population of multi-proton final states. Contributions predicted for scattering from a nucleon pair have both properties; the model tested in this analysis is a significant improvement but does not fully describe the data. We present the results as a double-differential cross section to enable further investigation of nuclear models. Improved description of the effects of the nuclear environment are required by current and future neutrino oscillation experiments.

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arXiv2019

Measurement of $\barν_μ$ charged-current single $π^{-}$ production on hydrocarbon in the few-GeV region using MINERvA

The antineutrino scattering channel $\barν_μ \,\text{CH} \rightarrow μ^{+} \,π^{-} \,X$(nucleon(s)) is analyzed in the incident energy range 1.5 to 10 GeV using the MINERvA detector at Fermilab. Differential cross sections are reported as functions of $μ^{+}$ momentum and production angle, $π^{-}$ kinetic energy and production angle, and antineutrino energy and squared four-momentum transfer. Distribution shapes are generally reproduced by simulations based on the GENIE, NuWro, and GiBUU event generators, however GENIE (GiBUU) overestimates (underestimates) the cross-section normalizations by 8% (10%). Comparisons of data with the GENIE-based reference simulation probe conventional treatments of cross sections and pion intranuclear rescattering. The distribution of non-track vertex energy is used to decompose the signal sample into reaction categories, and cross sections are determined for the exclusive reactions $μ^{+} π^{-} n$ and $ μ^+ π^{-} p$. A similar treatment applied to the published MINERvA sample $\barν_μ \,\text{CH} \rightarrow μ^{+} \,π^{0} \,X$(nucleon(s)) has determined the $μ^{+} π^{0} n$ cross section, and the latter is used with $σ(π^{-} n)$ and $σ(π^{-} p)$ to carry out an isospin decomposition of $\barν_μ$-induced CC($π$). The ratio of magnitudes and relative phase for isospin amplitudes $A_{3}$ and $A_{1}$ thereby obtained are: $R^{\barν} = 0.99 \pm 0.19$ and $ϕ^{\barν} = 93^{\circ} \pm 7^{\circ}$. Our results are in agreement with bubble chamber measurements made four decades ago.

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arXiv2019

Antineutrino Charged-Current reactions on Hydrocarbon with Low Momentum Transfer

We report on multinucleon effects in low momentum transfer ($< 0.8$ GeV/c) anti-neutrino interactions on plastic (CH) scintillator. These data are from the 2010-2011 antineutrino phase of the MINERvA experiment at Fermilab. The hadronic energy spectrum of this inclusive sample is well described when a screening effect at low energy transfer and a two-nucleon knockout process are added to a relativistic Fermi gas model of quasielastic, $Δ$ resonance, and higher resonance processes. In this analysis, model elements introduced to describe previously published neutrino results have quantitatively similar benefits for this antineutrino sample. We present the results as a double-differential cross section to accelerate investigation of alternate models for antineutrino scattering off nuclei.

hep-ex↗

arXiv2018

Reducing model bias in a deep learning classifier using domain adversarial neural networks in the MINERvA experiment

We present a simulation-based study using deep convolutional neural networks (DCNNs) to identify neutrino interaction vertices in the MINERvA passive targets region, and illustrate the application of domain adversarial neural networks (DANNs) in this context. DANNs are designed to be trained in one domain (simulated data) but tested in a second domain (physics data) and utilize unlabeled data from the second domain so that during training only features which are unable to discriminate between the domains are promoted. MINERvA is a neutrino-nucleus scattering experiment using the NuMI beamline at Fermilab. $A$-dependent cross sections are an important part of the physics program, and these measurements require vertex finding in complicated events. To illustrate the impact of the DANN we used a modified set of simulation in place of physics data during the training of the DANN and then used the label of the modified simulation during the evaluation of the DANN. We find that deep learning based methods offer significant advantages over our prior track-based reconstruction for the task of vertex finding, and that DANNs are able to improve the performance of deep networks by leveraging available unlabeled data and by mitigating network performance degradation rooted in biases in the physics models used for training.

physics.data-an↗

arXiv2018

Measurement of Quasielastic-Like Neutrino Scattering at $\left< E_ν\right> \sim 3.5$~ GeV on a Hydrocarbon Target

MINERvA presents a new analysis of neutrino induced quasielastic-like interactions in a hydrocarbon tracking target. We report a double-differential cross section using the muon transverse and longitudinal momentum. In addition, differential cross sections as a function of the square of the four-momentum transferred and the neutrino energy are calculated using a quasielastic hypothesis. Finally, an analysis of energy deposited near the interaction vertex is presented. These results are compared to modified GENIE predictions as well as a NuWro prediction. All results use a dataset produced by $3.34\times10^{20}$ protons on target creating a neutrino beam with a peak energy of approximately 3.5 GeV

hep-ex↗

arXiv2018

Cross sections for neutrino and antineutrino induced pion production on hydrocarbon in the few-GeV region using MINERvA

Separate samples of charged-current pion production events representing two semi-inclusive channels $ν_μ$-CC($π^{+}$) and $\barν_μ$-CC($π^{0}$) have been obtained using neutrino and antineutrino exposures of the MINERvA detector. Distributions in kinematic variables based upon $μ^{\pm}$-track reconstructions are analyzed and compared for the two samples. The differential cross sections for muon production angle, muon momentum, and four-momentum transfer $Q^2$, are reported, and cross sections versus neutrino energy are obtained. Comparisons with predictions of current neutrino event generators are used to clarify the role of the $Δ(1232)$ and higher-mass baryon resonances in CC pion production and to show the importance of pion final-state interactions. For the $ν_μ$-CC($π^{+}$) ($\barν_μ$-CC($π^{0}$)) sample, the absolute data rate is observed to lie below (above) the predictions of some of the event generators by amounts that are typically 1-to-2 $σ$. However the generators are able to reproduce the shapes of the differential cross sections for all kinematic variables of either data set.

hep-ex↗

arXiv2018

Measurement of final-state correlations in neutrino muon-proton mesonless production on hydrocarbon at $\langle E_ν\rangle=3$ GeV

Final-state kinematic imbalances are measured in mesonless production of $ν_μ+ A \to μ^- + p + X$ in the MINERvA tracker. Initial- and final-state nuclear effects are probed using the direction of the $μ^-$-p transverse momentum imbalance and the initial-state momentum of the struck neutron. Differential cross sections are compared to predictions based on current approaches to medium modeling. These models under-predict the cross section at intermediate intranuclear momentum transfers that generally exceed the Fermi momenta. As neutrino interaction models need to correctly incorporate the effect of the nucleus in order to predict neutrino energy resolution in oscillation experiments, this result points to a region of phase space where additional cross section strength is needed in current models, and demonstrates a new technique that would be suitable for use in fine grained liquid argon detectors where the effect of the nucleus may be even larger.

hep-ex↗

arXiv2018

Measurement of the muon anti-neutrino double-differential cross section for quasi-elastic scattering on hydrocarbon at~$E_ν\sim 3.5$ GeV

We present double-differential measurements of anti-neutrino quasi-elastic scattering in the MINERvA detector. This study improves on a previous single differential measurement by using updated reconstruction algorithms and interaction models, and provides a complete description of observed muon kinematics in the form of a double-differential cross section with respect to muon transverse and longitudinal momentum. We include in our signal definition zero-meson final states arising from multi-nucleon interactions and from resonant pion production followed by pion absorption in the primary nucleus. We find that model agreement is considerably improved by a model tuned to MINERvA inclusive neutrino scattering data that incorporates nuclear effects such as weak nuclear screening and two-particle, two-hole enhancements.

hep-ex↗

arXiv2018

Measurement of Total and Differential Cross Sections of Neutrino and Antineutrino Coherent $π^\pm$ Production on Carbon

Neutrino induced coherent charged pion production on nuclei, $\overlineν_μA\toμ^\pmπ^\mp A$, is a rare inelastic interaction in which the four-momentum squared transfered to the nucleus is nearly zero, leaving it intact. We identify such events in the scintillator of MINERvA by reconstructing |t| from the final state pion and muon momenta and by removing events with evidence of energetic nuclear recoil or production of other final state particles. We measure the total neutrino and antineutrino cross sections as a function of neutrino energy between 2 and 20 GeV and measure flux integrated differential cross sections as a function of $Q^2$, $E_π$ and $θ_π$. The $Q^2$ dependence and equality of the neutrino and anti-neutrino cross-sections at finite $Q^2$ provide a confirmation of Adler's PCAC hypothesis.

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arXiv2018

Measurement of the antineutrino to neutrino charged-current interaction cross section ratio in MINERvA

We present measurements of the neutrino and antineutrino total charged-current cross sections on carbon and their ratio using the MINERvA scintillator-tracker. The measurements span the energy range 2-22 GeV and were performed using forward and reversed horn focusing modes of the Fermilab low-energy NuMI beam to obtain large neutrino and antineutrino samples. The flux is obtained using a sub-sample of charged-current events at low hadronic energy transfer along with precise higher energy external neutrino cross section data overlapping with our energy range between 12-22 GeV. We also report on the antineutrino-neutrino cross section ratio, Rcc, which does not rely on external normalization information. Our ratio measurement, obtained within the same experiment using the same technique, benefits from the cancellation of common sample systematic uncertainties and reaches a precision of 5% at low energy. Our results for the antineutrino-nucleus scattering cross section and for Rcc are the most precise to date in the energy range $E_ν <$ 6GeV.

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arXiv2017

Measurement of neutral-current $K^+$ production by neutrinos using MINERvA

Neutral-current production of $K^{+}$ by atmospheric neutrinos is a background in searches for the proton decay $p \rightarrow K^{+} \barν$. Reactions such as $νp \rightarrow νK^{+} Λ$ are indistinguishable from proton decays when the decay products of the $Λ$ are below detection threshold. Events with $K^{+}$ are identified in MINERvA by reconstructing the timing signature of a $K^{+}$ decay at rest. A sample of 201 neutrino-induced neutral-current $K^{+}$ events is used to measure differential cross sections with respect to the $K^{+}$ kinetic energy, and the non-$K^{+}$ hadronic visible energy. An excess of events at low hadronic visible energy is observed relative to the prediction of the NEUT event generator. Good agreement is observed with the cross section prediction of the GENIE generator. A search for photons from $π^{0}$ decay, which would veto a neutral-current $K^{+}$ event in a proton decay search, is performed, and a 2$σ$ deficit of detached photons is observed relative to the GENIE prediction.

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arXiv2017

Constraints on Large Extra Dimensions from the MINOS Experiment

We report new constraints on the size of large extra dimensions from data collected by the MINOS experiment between 2005 and 2012. Our analysis employs a model in which sterile neutrinos arise as Kaluza-Klein states in large extra dimensions and thus modify the neutrino oscillation probabilities due to mixing between active and sterile neutrino states. Using Fermilab's NuMI beam exposure of $10.56 \times 10^{20}$ protons-on-target, we combine muon neutrino charged current and neutral current data sets from the Near and Far Detectors and observe no evidence for deviations from standard three-flavor neutrino oscillations. The ratios of reconstructed energy spectra in the two detectors constrain the size of large extra dimensions to be smaller than $0.45\,μ\text{m}$ at 90% C.L. in the limit of a vanishing lightest active neutrino mass. Stronger limits are obtained for non-vanishing masses.

hep-ex↗

arXiv2016

A search for flavor-changing non-standard neutrino interactions using $ν_{e}$ appearance in MINOS

We report new constraints on flavor-changing non-standard neutrino interactions from the MINOS long-baseline experiment using $ν_{e}$ and $\barν_{e}$ appearance candidate events from predominantly $ν_μ$ and $\barν_μ$ beams. We used a statistical selection algorithm to separate $ν_{e}$ candidates from background events, enabling an analysis of the combined MINOS neutrino and antineutrino data. We observe no deviations from standard neutrino mixing, and thus place constraints on the non-standard interaction matter effect, $|\varepsilon_{eτ}|$, and phase, $(δ_{CP}+δ_{eτ})$, using a thirty-bin likelihood fit.

hep-ex↗

arXiv2016

Search for time-independent Lorentz violation using muon neutrino to muon antineutrino transitions in MINOS

Data from the MINOS experiment has been used to search for mixing between muon neutrinos and muon antineutrinos using a time-independent Lorentz-violating formalism derived from the Standard-Model Extension (SME). MINOS is uniquely capable of searching for muon neutrino-antineutrino mixing given its long baseline and ability to distinguish between neutrinos and antineutrinos on an event-by-event basis. Neutrino and antineutrino interactions were observed in the MINOS Near and Far Detectors from an exposure of 10.56$\times10^{20}$ protons-on-target from the NuMI neutrino-optimized beam. No evidence was found for such transitions and new, highly stringent limits were placed on the SME coefficients governing them. We place the first limits on the SME parameters $(c_{L})^{TT}_{μμ} $ and $(c_{L})^{TT}_{ττ}$ at $-8.4\times10^{-23} < (c_{L})^{TT}_{μμ} < 8.0\times10^{-23}$ and $-8.0\times10^{-23} < (c_{L})^{TT}_{ττ} < 8.4\times10^{-23}$, and the world's best limits on the $\tilde{g}^{ZT}_{μ\overlineμ}$ and $\tilde{g}^{ZT}_{τ\overlineτ}$ parameters at $|\tilde{g}^{ZT}_{μ\overlineμ}| < 3.3\times 10^{-23}$ and $|\tilde{g}^{ZT}_{τ\overlineτ}| < 3.3\times 10^{-23}$, all limits quoted at $3σ$.

hep-ex↗

arXiv2016

Measurement of electron neutrino quasielastic and quasielastic-like scattering on hydrocarbon at $\langle E_ν \rangle $ = 3.6 GeV

The first direct measurement of electron-neutrino quasielastic and quasielastic-like scattering on hydrocarbon in the few-GeV region of incident neutrino energy has been carried out using the MINERvA detector in the NuMI beam at Fermilab. The flux-integrated differential cross sections in electron production angle, electron energy and $Q^{2}$ are presented. The ratio of the quasielastic, flux-integrated differential cross section in $Q^{2}$ for $ν_{e}$ with that of similarly-selected $ν_μ$-induced events from the same exposure is used to probe assumptions that underpin conventional treatments of charged-current $ν_{e}$ interactions used by long-baseline neutrino oscillation experiments. The data are found to be consistent with lepton universality and are well-described by the predictions of the neutrino event generator GENIE.

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