Neutrino beam flux prediction 2020
The files in the following archive file contain the neutrino and antineutrino beam flux predictions for the T2K ND280 (near) and Super-Kamiokande (far) detectors. It supersedes the previous flux release in 2016.
Since the previous flux release, the flux prediction has been updated to use 2009 replica target data from the NA61/SHINE experiment to tune interactions inside of the neutrino production target. The NA61/SHINE 2009 replica target measurements of π± production are published in Eur. Phys. J. C (2016) 76: 617. The flux prediction released here corresponds to that used in the T2K 2020 oscillation physics result paper (to be submitted to Eur. Phys. J. C).
The provided flux predictions include no neutrino oscillations.
A matrix which encodes the covariance between different energy bins of the fluxes at the near and far detectors for both horn operation modes is also provided in this release.
The provided tar file contains the flux predictions, covariance matrix, and a README.pdf file with detailed information on the included files:
T2K 2020 flux prediction
Data release for the “First T2K measurement of transverse kinematic imbalance in the muon neutrino charged-current single π+ production channel containing at least one proton”
This data release contains the data corresponding to the article “First T2K measurement of transverse kinematic imbalance in the muon neutrino charged-current single π+ production channel containing at least one proton”. The related article can be found at this link, arXiV:2102.03346
Improved constraints on neutrino mixing from the T2K experiment with 3.13E21 protons on target
The T2K experiment reports updated measurements of neutrino and antineutrino oscillations using both appearance and disappearance channels. This result comes from an exposure of 14.9 (16.4) × 1020 protons on target in neutrino (antineutrino) mode. For fits including a constraint on sin2θ13 from reactor data and assuming normal mass ordering, T2K measures sin2θ23 = 0.53+0.03-0.04 and Δ m223 = (2.45 ± 0.07) × 10-3 eV2c-4.
The Bayesian analyses show a weak preference for normal mass ordering (89% posterior probability) and the upper sin2θ23 octant (80% posterior probability), with a uniform prior probability assumed in both cases. The T2K data exclude CP conservation in neutrino oscillations at the 2σ level.
Oscillation results from Neutrino 2020
This archive contains the electronic version (ROOT format) of the results of the measurements of oscillation parameters presented by T2K at Neutrino 2020 (Preliminary run 1-10 results). Both Bayesian and frequentist results are provided for the different oscillation parameters, with 2D confidence/credible regions and 1D DeltaChi2/posterior probability distributions.
Citation: Dunne, Patrick. (2020, July). Latest Neutrino Oscillation Results from T2K https://doi.org/10.5281/zenodo.3959558
Data release for the “Measurement of the charged-current electron (anti-)neutrino inclusive cross-sections at the T2K off-axis near detector ND280”
This data release is associated with the publication “Measurement of the charged-current electron (anti-)neutrino inclusive cross-sections at the T2K off-axis near detector ND280”. It is currently available on arXiv and in JHEP:
arXiv:2002.11986 [hep-ex] and J. High Energ. Phys. 2020, 114 (2020)
When citing this data release, please cite as well the paper.
The full author list and acknowledgements for the T2K collaboration are described in the article.
The data release contains:
- cross-section measurements with NEUT 5.3.2 (fraction and total with covariances)
- cross-section measurements with GENIE 2.8.0 (fraction and total with covariances)
- smearing matrices for selected electron/positron momentum
Description:
The cross-section measurements are provided in the form of text files and a PDF summary. The detailed method and results are presented in the paper (especially section 8).
The smearing matrices are provided as one ROOT file with two 2D histograms showing the electron/positron smearing matrices for momentum and angle, obtained using the selection from the ND280 nue CC inclusive analysis. It is similar to the figure 10 of the paper, but with more statistics and finer binning. They are accompanied with a README file presenting how to use these matrices and the related caveats. Please read it carefully.
We strongly encourage any users of the matrices to present these caveats alongside any public comparison to T2K data.
Full abstract:
The electron (anti-)neutrino component of the T2K neutrino beam constitutes the largest background in the measurement of electron (anti-)neutrino appearance at the far detector. The electron neutrino scattering is measured directly with the T2K off-axis near detector, ND280. The selection of the electron (anti-)neutrino events in the plastic scintillator target from both neutrino and anti-neutrino mode beams is discussed in this paper. The flux integrated single differential charged-current inclusive electron (anti-)neutrino cross-sections, dσ/dp and dσ/dcos(θ), and the total cross-sections in a limited phase-space in momentum and scattering angle (p>300 MeV/c and θ≤45∘) are measured using a binned maximum likelihood fit and compared to the neutrino Monte Carlo generator predictions, resulting in good agreement.
Data release for “First Measurement of the Charged Current antinumu Double Differential Cross Section on a Water Target without Pions in the final state”
This page will show the data release for the paper, “First Measurement of the Charged Currentantinumu Double Differential Cross Section on a Water Target without Pions in the final state.” This has been published in Phys. Rev. D 102 (2020) 012007.
Data release for the “Constraint on the matter–antimatter symmetry-violating phase in neutrino oscillations” paper
This is the data release to accompany the results of T2K’s neutrino oscillation analysis using neutrino and antineutrino data collected between 2010 and 2018, as reported in the T2K collaboration’s April 16th 2020 article in Nature.
The information shared is the value of minus two times the log of the marginal likelihood (described in the methods section of the Nature article) as a function of several of the neutrino oscillation parameters. This is referred to as the “χ2”. We also give δχ2 distributions, which are the difference in the χ2 value between the minimum χ2 and the χ2 at the other points in oscillation parameter space. Additionally, 68% and 90% confidence level contours are included in one of the two file formats detailed below. All distributions and contours have nth and ith versions which give the information for the normal and inverted neutrino mass orderings respectively.
Nature publication is available from: https://www.nature.com/articles/s41586-020-2177-0#citeas
T2K neutrino oscillation public data release.
Data release for the paper “Simultaneous measurement of the muon neutrino charged-current cross section on oxygen and carbon without pions in the final state at T2K”
his paper reports the first simultaneous measurement of the double differential muon neutrino charged-current cross section on oxygen and carbon without pions in the final state as a function of the outgoing muon kinematics, made at the ND280 off-axis near detector of the T2K experiment. The ratio of the oxygen and carbon cross sections is also provided to help validate various models’ ability to extrapolate between carbon and oxygen nuclear targets, as is required in T2K oscillation analyses. The data are taken using a neutrino beam with an energy spectrum peaked at 0.6~GeV and comprises 57.34$\times$10$^{19}$ protons on target. The extracted measurement is compared with the prediction from different Monte Carlo neutrino-nucleus interaction event generators, showing particular model separation for very forward-going muons. Overall, of the models tested, the result is best described using Local Fermi Gas descriptions of the nuclear ground state with RPA suppression.
Data release for the “First combined measurement of the muon neutrino and antineutrino charged-current cross section without pions in the final state at T2K”
This data release contains the data corresponding to the article “ First combined measurement of the muon neutrino and antineutrino charged-current cross-section without pions in the final state at T2K” published by T2K (ArXiv: https://arxiv.org/abs/2002.09323).
Search for light sterile neutrinos with the T2K far detector Super-Kamiokande at a baseline of 295 km
This data release contains the delta_chisq surface and confidence regions of the long baseline sterile neutrino search as a function of sinsqth24 and sinsqth34.
