Over the last decade, there has been enormous effort to measure neutrino interaction cross sections important to oscillation experiments. However, a number of results from modern experiments appear ...to be in tension with each other, despite purporting to measure the same processes. The TENSIONS2016 workshop was held at University of Pittsburgh July 24–31, 2016 and was sponsored by the Pittsburgh Particle Physics, Astronomy, and Cosmology Center (PITT PACC). The focus was on bringing experts from three experimental collaborations together to compare results in detail and try to find the source of tension by clarifying and comparing signal definitions and the analysis strategies used for each measurement. A set of comparisons between the measurements using a consistent set of models was also made. This paper summarizes the main conclusions of that work.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
Knowledge of the neutrino flux produced by the Neutrinos at the Main Injector (NuMI) beamline is essential to the neutrino oscillation and neutrino interaction measurements of the MINERvA, MINOS+, ...NOvA and MicroBooNE experiments at Fermi National Accelerator Laboratory. We have produced a flux prediction which uses all available and relevant hadron production data, incorporating measurements of particle production off of thin targets as well as measurements of particle yields from a spare NuMI target exposed to a 120 GeV proton beam. The result is the most precise flux prediction achieved for a neutrino beam in the one to tens of GeV energy region. We have also compared the prediction to in situ measurements of the neutrino flux and find good agreement.
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CMK, CTK, FMFMET, IJS, NUK, PNG, UM
Measurements of inclusive spectra and mean multiplicities of
π
±
, K
±
, p and
p
¯
produced in inelastic p + p interactions at incident projectile momenta of 20, 31, 40, 80 and 158
GeV
/
c
(
s
=
...6.3, 7.7, 8.8, 12.3 and 17.3
GeV
, respectively) were performed at the CERN Super Proton Synchrotron using the large acceptance NA61/SHINE hadron spectrometer. Spectra are presented as function of rapidity and transverse momentum and are compared to predictions of current models. The measurements serve as the baseline in the NA61/SHINE study of the properties of the onset of deconfinement and search for the critical point of strongly interacting matter.
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DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
A set of comparisons among neutrino interaction experiments MiniBooNE, MINERvA, Tokai-to-Kamioka (T2K), and MicroBooNE is presented. This gives a broad view of the field of neutrino-nucleus ...interactions. The emphasis is on charged-current inclusive, quasielastic-like, and pion production experiments. Measurements are compared in new ways. Comparisons of recent data with available event generator codes are made more comprehensively than is regularly found in most previous publications. Generator studies show sensitivities for experimental model dependence. Efficiencies calculated with different generators are presented in a novel way. A comparison of different forward-folding techniques is also presented.
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Elastic neutrino scattering on electrons is a precisely known purely leptonic process that provides a standard candle for measuring neutrino flux in conventional neutrino beams. Using a total sample ...of 810 neutrino-electron scatters after background subtraction, the measurement reduces the normalization uncertainty on the ν μ NuMI beam flux between 2 and 20 GeV from 7.6 to 3.9%. This is the most precise measurement of neutrino-electron scattering to date, will reduce uncertainties on MINER ν A's absolute cross section measurements, and demonstrates a technique that can be used in future neutrino beams such as long baseline neutrino facility.
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Scattering of high energy particles from nucleons probes their structure, as was done in the experiments that established the non-zero size of the proton using electron beams
. The use of charged ...leptons as scattering probes enables measuring the distribution of electric charges, which is encoded in the vector form factors of the nucleon
. Scattering weakly interacting neutrinos gives the opportunity to measure both vector and axial vector form factors of the nucleon, providing an additional, complementary probe of their structure. The nucleon transition axial form factor, F
, can be measured from neutrino scattering from free nucleons, ν
n → μ
p and Formula: see text, as a function of the negative four-momentum transfer squared (Q
). Up to now, F
(Q
) has been extracted from the bound nucleons in neutrino-deuterium scattering
, which requires uncertain nuclear corrections
. Here we report the first high-statistics measurement, to our knowledge, of the Formula: see text cross-section from the hydrogen atom, using the plastic scintillator target of the MINERvA
experiment, extracting F
from free proton targets and measuring the nucleon axial charge radius, r
, to be 0.73 ± 0.17 fm. The antineutrino-hydrogen scattering presented here can access the axial form factor without the need for nuclear theory corrections, and enables direct comparisons with the increasingly precise lattice quantum chromodynamics computations
. Finally, the tools developed for this analysis and the result presented are substantial advancements in our capabilities to understand the nucleon structure in the weak sector, and also help the current and future neutrino oscillation experiments
to better constrain neutrino interaction models.
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GEOZS, IJS, IMTLJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBMB, UL, UM, UPUK, ZAGLJ
We measure neutrino charged-current quasielasticlike scattering on hydrocarbon at high statistics using the wideband Neutrinos at the Main Injector beam with neutrino energy peaked at 6 GeV. The ...double-differential cross section is reported in terms of muon longitudinal (p_{∥}) and transverse (p_{⊥}) momentum. Cross section contours versus lepton momentum components are approximately described by a conventional generator-based simulation, however, discrepancies are observed for transverse momenta above 0.5 GeV/c for longitudinal momentum ranges 3-5 and 9-20 GeV/c. The single differential cross section versus momentum transfer squared (dσ/dQ_{QE}^{2}) is measured over a four-decade range of Q^{2} that extends to 10 GeV^{2}. The cross section turnover and falloff in the Q^{2} range 0.3-10 GeV^{2} is not fully reproduced by generator predictions that rely on dipole form factors. Our measurement probes the axial-vector content of the hadronic current and complements the electromagnetic form factor data obtained using electron-nucleon elastic scattering. These results help oscillation experiments because they probe the importance of various correlations and final-state interaction effects within the nucleus, which have different effects on the visible energy in detectors.
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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. The widely used pion production model in GENIE is compared to four MINERνA charged current pion production measurements using nuisance. Tunings, i.e., adjustments of model parameters, to help match GENIE to MINERνA and older bubble chamber data are presented. We find that scattering off nuclear targets as measured in MINERνA is not in good agreement with expectations based upon scattering off nucleon (hydrogen or deuterium) targets in existing bubble chamber data. An additional ad hoc correction for the low−Q2 region, where collective nuclear effects are expected to be large, is 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 framework allows for straightforward extensions to other neutrino event generators and models, and allows omitting and including new datasets as they become available.
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