51 research outputs found
Search for short baseline nu(e) disappearance with the T2K near detector
8 pages, 6 figures, submitted to PRD rapid communication8 pages, 6 figures, submitted to PRD rapid communicationWe thank the J-PARC staff for superb accelerator performance and the CERN NA61 collaboration for providing valuable particle production data. We acknowledge the support of MEXT, Japan; NSERC, NRC and CFI, Canada; Commissariat `a l’Energie Atomique and Centre National de la Recherche Scientifique–Institut National de Physique Nucle´aire et de Physique des Particules, France; DFG, Germany; INFN, Italy; National Science Centre (NCN), Poland; Russian Science Foundation, RFBR and Ministry of Education and Science, Russia; MINECO and European Regional Development Fund, Spain; Swiss National Science Foundation and State Secretariat for Education, Research and Innovation, Switzerland; STFC, UK; and DOE, USA. We also thank CERN for the UA1/NOMAD magnet, DESY for the HERA-B magnet mover system, NII for SINET4, the WestGrid and SciNet consortia in Compute Canada, GridPP, UK. In addition participation of individual researchers and institutions has been further supported by funds from ERC (FP7), EU; JSPS, Japan; Royal Society, UK; DOE Early Career program, USA
The SMRD subdetector at the T2K near detector station
The T2K long-baseline neutrino oscillation experiment is running in Japan. The primary goals of the T2K are measurement of the mixing angle 13, and precise measurements of the mixing angle 23 and of the mass difference m2 23. The installation of the near detector complex was completed and first data were already registered. This article presents operation of the Side Muon Range Detector, a component of the Off-Axis near detector. Detector concept and implementation are presented, followed by a description of cosmic muon track reconstruction algorithm and finally current status
Measurement of double-differential muon neutrino charged-current interactions on C8 H8 without pions in the final state using the T2K off-axis beam
We report the measurement of muon neutrino charged-current interactions on carbon without pions in the final state at the T2K beam energy using 5.734×1020 protons on target. For the first time the measurement is reported as a flux-integrated, double-differential cross section in muon kinematic variables (cosθμ, pμ), without correcting for events where a pion is produced and then absorbed by final state interactions. Two analyses are performed with different selections, background evaluations and cross-section extraction methods to demonstrate the robustness of the results against biases due to model-dependent assumptions. The measurements compare favorably with recent models which include nucleon-nucleon correlations but, given the present precision, the measurement does not distinguish among the available models. The data also agree with Monte Carlo simulations which use effective parameters that are tuned to external data to describe the nuclear effects. The total cross section in the full phase space is σ=(0.417±0.047(syst)±0.005(stat))×10-38 cm2 nucleon-1 and the cross section integrated in the region of phase space with largest efficiency and best signal-over-background ratio (cosθμ>0.6 and pμ>200 MeV) is σ=(0.202±0.036(syst)±0.003(stat))×10-38 cm2 nucleon-1
Measurement of the muon neutrino inclusive charged-current cross section in the energy range of 1–3 GeV with the T2K INGRID detector
We report a measurement of the νμ-nucleus inclusive charged-current cross section (¼ σcc) on iron using
data from the INGRID detector exposed to the J-PARC neutrino beam. The detector consists of 14 modules
in total, which are spread over a range of off-axis angles from 0° to 1.1°. The variation in the neutrino
energy spectrum as a function of the off-axis angle, combined with event topology information, is used to
calculate this cross section as a function of neutrino energy. The cross section is measured to be
σccð1.1 GeVÞ ¼ 1.10 0.15 ð10−38 cm2=nucleonÞ, σccð2.0 GeVÞ ¼ 2.07 0.27 ð10−38 cm2=nucleonÞ,
and σccð3.3 GeVÞ ¼ 2.29 0.45 ð10−38 cm2=nucleonÞ, at energies of 1.1, 2.0, and 3.3 GeV, respectively.
These results are consistent with the cross section calculated by the neutrino interaction generators
currently used by T2K. More importantly, the method described here opens up a new way to determine the
energy dependence of neutrino-nucleus cross sections
First measurement of the muon neutrino charged current single pion production cross section on water with the T2K near detector
The T2K off-axis near detector, ND280, is used to make the first differential cross section measurements
of muon neutrino charged current single positive pion production on a water target at energies ∼0.8 GeV.
The differential measurements are presented as a function of the muon and pion kinematics, in the restricted
phase space defined by pπþ > 200 MeV=c, pμ > 200 MeV=c, cosðθπþ Þ > 0.3 and cosðθμÞ > 0.3. The
total flux integrated νμ charged current single positive pion production cross section on water in the
restricted phase space is measured to be hσiϕ ¼ 4.25 0.48ðstatÞ 1.56ðsystÞ × 10−40 cm2=nucleon.
The total cross section is consistent with the NEUT prediction (5.03 × 10−40 cm2=nucleon) and 2σ lower
than the GENIE prediction (7.68 × 10−40 cm2=nucleon). The differential cross sections are in good
agreement with the NEUT generator. The GENIE simulation reproduces well the shapes of the
distributions, but overestimates the overall cross section normalization
Measurement of Muon Antineutrino Oscillations with an Accelerator-Produced Off-Axis Beam.
T2K reports its first measurements of the parameters governing the disappearance of ν[over ¯]_{μ} in an off-axis beam due to flavor change induced by neutrino oscillations. The quasimonochromatic ν[over ¯]_{μ} beam, produced with a peak energy of 0.6 GeV at J-PARC, is observed at the far detector Super-Kamiokande, 295 km away, where the ν[over ¯]_{μ} survival probability is expected to be minimal. Using a data set corresponding to 4.01×10^{20} protons on target, 34 fully contained μ-like events were observed. The best-fit oscillation parameters are sin^{2}(θ[over ¯]_{23})=0.45 and |Δm[over ¯]_{32}^{2}|=2.51×10^{-3} eV^{2} with 68% confidence intervals of 0.38-0.64 and 2.26-2.80×10^{-3} eV^{2}, respectively. These results are in agreement with existing antineutrino parameter measurements and also with the ν_{μ} disappearance parameters measured by T2K
Updated T2K measurements of muon neutrino and antineutrino disappearance using 1.5 x 10(21) protons on target
We report measurements by the T2K experiment of the parameters
and governing the disappearance of muon neutrinos and
antineutrinos in the three flavor neutrino oscillation model. Utilizing the
ability of the experiment to run with either a mainly neutrino or a mainly
antineutrino beam, the parameters are measured separately for neutrinos and
antineutrinos. Using POT in neutrino running mode and
POT in antineutrino mode, T2K obtained,
and eV/c for neutrinos, and
and
eV/c for antineutrinos (assuming normal mass ordering). No
significant differences between the values of the parameters describing the
disappearance of muon neutrinos and antineutrinos were observed.Comment: 8 pages, 2 figure
Measurement of the Inclusive Electron Neutrino Charged Current Cross Section on Carbon with the T2K Near Detector
The T2K off-axis near detector ND280 is used to make the first differential cross-section measurements of electron neutrino charged current interactions at energies similar to 1 GeV as a function of electron momentum, electron scattering angle, and four-momentum transfer of the interaction. The total flux-averaged nu(e) charged current cross section on carbon is measured to be (phi) = 1.11 +/- 0.10(stat) +/- 0.18(syst) x 10(-38) cm(2)/nucleon. The differential and total cross- section measurements agree with the predictions of two leading neutrino interaction generators, NEUT and GENIE. The NEUT prediction is 1.23 x 10(-38) cm(2)/nucleon and the GENIE prediction is 1.08 x 10(-38) cm(2)/nucleon. The total nu(e) charged current cross-section result is also in agreement with data from the Gargamelle experiment
Testing charged current quasi-elastic and multinucleon interaction models in the NEUT neutrino interaction generator with published datasets from the MiniBooNE and MINERνA experiments
The MiniBooNE large axial mass anomaly has prompted a great deal of theoretical work on
sophisticated Charged Current Quasi-Elastic (CCQE) neutrino interaction models in recent years.
As the dominant interaction mode at T2K energies, and the signal process in oscillation analyses, it
is important for the T2K experiment to include realistic CCQE cross section uncertainties in T2K
analyses. To this end, T2K’s Neutrino Interaction Working Group has implemented a number of
recent models in NEUT, T2K’s primary neutrino interaction event generator. In this paper, we
give an overview of the models implemented, and present fits to published νµ and νµ CCQE cross
section measurements from the MiniBooNE and MINERνA experiments. The results of the fits
are used to select a default cross section model for future T2K analyses, and to constrain the cross
section uncertainties of the model. We find a model consisting of a modified relativistic Fermi gas
model and multinucleon interactions most consistently describes the available data
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