0000000000040893
AUTHOR
D. Autiero
Study of scintillation light collection, production and propagation in a 4 tonne dual-phase LArTPC
The $3 \times 1 \times 1$ m$^3$ demonstrator is a dual phase liquid argon time projection chamber that has recorded cosmic rays events in 2017 at CERN. The light signal in these detectors is crucial to provide precise timing capabilities. The performances of the photon detection system, composed of five PMTs, are discussed. The collected scintillation and electroluminescence light created by passing particles has been studied in various detector conditions. In particular, the scintillation light production and propagation processes have been analyzed and compared to simulations, improving the understanding of some liquid argon properties.
Measurement of Coherent π+ Production in Low Energy Neutrino-Carbon Scattering
We report the first measurement of the flux-averaged cross section for charged current coherent π+ production on carbon for neutrino energies less than 1.5 GeV, and with a restriction on the final state phase space volume in the T2K near detector, ND280. Comparisons are made with predictions from the Rein-Sehgal coherent production model and the model by Alvarez-Ruso et al., the latter representing the first implementation of an instance of the new class of microscopic coherent models in a neutrino interaction Monte Carlo event generator. We observe a clear event excess above background, disagreeing with the null results reported by K2K and SciBooNE in a similar neutrino energy region. The …
Search for the exotic Θ+ resonance in the NOMAD experiment
12 pages, 16 figures.-- PACS nrs.: 13.15.+g; 13.60.Le; 13.87.Fh; 14.40.Ev.-- ISI Article Identifier: 000243973100007.-- ArXiv pre-print available at: http://arxiv.org/abs/hep-ex/0612063.-- et al.
Search for short baseline nu(e) disappearance with the T2K near detector
8 pages.- 6 figures
A more sensitive search for νμ→ντ oscillations in NOMAD
With additional data and improved algorithms, we have enhanced the sensitivity of our appearance search for $\numunutau$ oscillations in the NOMAD detector in the CERN-SPS wide-band neutrino beam. The search uses kinematic criteria to identify $\nutau$ charged current interactions followed by decay of the $\tau^-$ to one of several decay modes. Our ``blind'' analyses of deep-inelastic scattering data taken in 1996 and 1997, combined with consistent reanalyses of previously reported 1995 data, yield no oscillation signal. For the two-family oscillation scenario, we present the contour outlining a 90\% C.L. confidence region in the $\sin^22\theta_{\mu \tau} - \Delta m^2$ plane. At large $\Del…
Volume IV The DUNE far detector single-phase technology
This document was prepared by the DUNE collaboration using the resources of the Fermi National Accelerator Laboratory (Fermilab), a U.S. Department of Energy, Office of Science, HEP User Facility. Fermilab is managed by Fermi Research Alliance, LLC (FRA), acting under Contract No. DE-AC02-07CH11359. The DUNE collaboration also acknowledges the international, national, and regional funding agencies supporting the institutions who have contributed to completing this Technical Design Report.
First results on ProtoDUNE-SP liquid argon time projection chamber performance from a beam test at the CERN Neutrino Platform
The ProtoDUNE-SP detector was constructed and operated on the CERN Neutrino Platform. We thank the CERN management for providing the infrastructure for this experiment and gratefully acknowledge the support of the CERN EP, BE, TE, EN, IT and IPT Departments for NP04/ProtoDUNE-SP. This documentwas prepared by theDUNEcollaboration using the resources of the Fermi National Accelerator Laboratory (Fermilab), a U.S. Department of Energy, Office of Science, HEP User Facility. Fermilab is managed by Fermi Research Alliance, LLC (FRA), acting under Contract No. DE-AC02-07CH11359. This work was supported by CNPq, FAPERJ, FAPEG and FAPESP, Brazil; CFI, IPP and NSERC, Canada; CERN; MSMT, Czech Republi…
Search for eV (pseudo)scalar penetrating particles in the SPS neutrino beam
We carried out a model-independent search for light scalar or pseudoscalar particles $a$'s (an example of which is the axion) that couple to two photons by using a photon-regeneration method at high energies allowing a substantial increase in the sensitivity to $eV$ masses.\ The experimental set-up is based on elements of the CERN West Area Neutrino Facility (WANF) beam line and theNOMAD neutrino detector.\ The new particles, if they exist, could be produced through the Primakoff effect in interactions of high energy photons, generated by the 450 $GeV$ protons in the CERN SPS neutrino target, with virtual photons from the WANF horn magnetic field.\ The particles would penetrate the downstre…
Neutrino interaction classification with a convolutional neural network in the DUNE far detector
The Deep Underground Neutrino Experiment is a next-generation neutrino oscillation experiment that aims to measure CP-violation in the neutrino sector as part of a wider physics program. A deep learning approach based on a convolutional neural network has been developed to provide highly efficient and pure selections of electron neutrino and muon neutrino charged-current interactions. The electron neutrino (antineutrino) selection efficiency peaks at 90% (94%) and exceeds 85% (90%) for reconstructed neutrino energies between 2–5 GeV. The muon neutrino (antineutrino) event selection is found to have a maximum efficiency of 96% (97%) and exceeds 90% (95%) efficiency for reconstructed neutrino…
Search for νμ→νe oscillations in the NOMAD experiment
We present the results of a search for vμ → v e oscillations in the NOMAD experiment at CERN. The experiment looked for the appearance of ve in a predominantly vμ wide-band neutrino beam at the CERN SPS. No evidence for oscillations was found. The 90% confidence limits obtained are Δm2 < 0.4 eV 2 for maximal mixing and sin2(2θ) < 1.4 × 10-3 for large Δm2. This result excludes the LSND allowed region of oscillation parameters with Δm2 ≳ 10 eV2. © 2003 Elsevier B.V. All rights reserved.
T2K neutrino flux prediction
The Tokai-to-Kamioka (T2K) experiment studies neutrino oscillations using an off-axismuon neutrino beam with a peak energy of about 0.6 GeV that originates at the Japan Proton Accelerator Research Complex accelerator facility. Interactions of the neutrinos are observed at near detectors placed at 280 m from the production target and at the far detector-Super-Kamiokande-located 295 km away. The flux prediction is an essential part of the successful prediction of neutrino interaction rates at the T2K detectors and is an important input to T2K neutrino oscillation and cross section measurements. A FLUKA and GEANT3-based simulation models the physical processes involved in the neutrino producti…
Combined Analysis of Neutrino and Antineutrino Oscillations at T2K.
T2K reports its first results in the search for CP violation in neutrino oscillations using appearance and disappearance channels for neutrino- and antineutrino-mode beams. The data include all runs from January 2010 to May 2016 and comprise 7.482 ×10^(20) protons on target in neutrino mode, which yielded in the far detector 32 e-like and 135 μ-like events, and 7.471 × 10^(20) protons on target in antineutrino mode, which yielded 4 e-like and 66 μ-like events. Reactor measurements of sin(2)2θ(13) have been used as an additional constraint. The one-dimensional confidence interval at 90% for the phase δCP spans the range (−3.13, −0.39) for normal mass ordering. The CP conservation hypothesis …
A Search for Single Photon Events in Neutrino Interactions
We present a search for neutrino induced events containing a single, exclusive photon using data from the NOMAD experiment at the CERN SPS where the average energy of the neutrino flux is ≃25 GeV. The search is motivated by an excess of electron-like events in the 200-475 MeV energy region as reported by the MiniBooNE experiment. In NOMAD, photons are identified via their conversion to e + e - in an active target embedded in a magnetic field. The background to the single photon signal is dominated by the asymmetric decay of neutral pions produced either in a coherent neutrino-nucleus interaction, or in a neutrino-nucleon neutral current deep inelastic scattering, or in an interaction occurr…
Production properties of $K*(892)\pm$ vector mesons and their spin alignment as measured in the NOMAD experiment
First measurements of K*(892) mesons production properties and their spin alignment in nu_mu charged current (CC) and neutral current (NC) interactions are presented. The analysis of the full data sample of the NOMAD experiment is performed in different kinematic regions. For K*+ and K*- mesons produced in nu_mu CC interactions and decaying into K0 pi+/- we have found the following yields per event: (2.6 +/- 0.2 (stat.) +/- 0.2 (syst.))% and (1.6 +/- 0.1 (stat.) +/- 0.1 (syst.))% respectively, while for the K*+ and K*- mesons produced in nu NC interactions the corresponding yields per event are: (2.5 +/- 0.3 (stat.) +/- 0.3 (syst.))% and (1.0 +/- 0.3 (stat.) +/- 0.2 (syst.))%. The results o…
Measurements of the T2K neutrino beam properties using the INGRID on-axis near detector
Precise measurement of neutrino beam direction and intensity was achieved based on a new concept with modularized neutrino detectors. INGRID (Interactive Neutrino GRID) is an on-axis near detector for the T2K long baseline neutrino oscillation experiment. INGRID consists of 16 identical modules arranged in horizontal and vertical arrays around the beam center. The module has a sandwich structure of iron target plates and scintillator trackers. INGRID directly monitors the muon neutrino beam profile center and intensity using the number of observed neutrino events in each module. The neutrino beam direction is measured with accuracy better than 0.4 mrad from the measured profile center. The …
Precision measurement of scaled momentum, charge multiplicity, and thrust in νμN and interactions
By focusing on the notion of electronic document, we differentiate two evolutions which are useful to distinct titles: on the one hand are the documents, which have value of reference. Its administrator will take care to preserve its integrity and its context of production which is strongly significant. On the other hand are resources, evolutionary elements by nature, which the user must be able to appropriate and who must thus be placed at the disposal so that the production is erased, to focus on a logic of exploitation and service.
A study of strange particle production in nu(mu) charged current interactions in the NOMAD experiment
A study of strange particle production in $\nu_\mu$ charged current interactions has been performed using the data from the NOMAD experiment. Yields of neutral strange particles ($K^0_s, \Lambda, \bar{\Lambda}$) have been measured. Mean multiplicities are reported as a function of the event kinematic variables $E_\nu$, $W^2$ and $Q^2$ as well as of the variables describing particle behaviour within a hadronic jet: $x_F$, $z$ and $p_T^2$. Decays of resonances and heavy hyperons with identified $K^0_s$ and $\Lambda$ in the final state have been analyzed. Clear signals corresponding to $\rm {K^\star}^\pm$ $\rm {\Sigma^\star}^\pm$, $\rm \Xi^-$ and $\rm \Sigma^0$ have been observed. A study of s…
Measurement of the muon neutrino inclusive charged-current cross section in the energy range of 1–3 GeV with the T2K INGRID detector
International audience; We report a measurement of the $\nu_{\mu}$-nucleus inclusive charged current cross section (=$\sigma^{cc}$) on iron using data from 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$^\circ$ to 1.1$^\circ$. 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 $\sigma^{cc}(1.1\text{ GeV}) = 1.10 \pm 0.15$ $(10^{-38}\text{cm}^2/\text{nucleon})$, $\sigma^{cc}(2.0\text{ GeV}) = 2.07 \pm 0.27$ $(10^{-38}\te…
Search for heavy neutrinos mixing with tau neutrinos
We report on a search for heavy neutrinos ($\nus$) produced in the decay $D_s\to \tau \nus$ at the SPS proton target followed by the decay $\nudecay$ in the NOMAD detector. Both decays are expected to occur if $\nus$ is a component of $\nu_{\tau}$.\ From the analysis of the data collected during the 1996-1998 runs with $4.1\times10^{19}$ protons on target, a single candidate event consistent with background expectations was found. This allows to derive an upper limit on the mixing strength between the heavy neutrino and the tau neutrino in the $\nus$ mass range from 10 to 190 $\rm MeV$. Windows between the SN1987a and Big Bang Nucleosynthesis lower limits and our result are still open for f…
The mass-hierarchy and CP-violation discovery reach of the LBNO long-baseline neutrino experiment.
The next generation neutrino observatory proposed by the LBNO collaboration will address fundamental questions in particle and astroparticle physics. The experiment consists of a far detector, in its first stage a 20 kt LAr double phase TPC and a magnetised iron calorimeter, situated at 2300 km from CERN and a near detector based on a high-pressure argon gas TPC. The long baseline provides a unique opportunity to study neutrino flavour oscillations over their 1st and 2nd oscillation maxima exploring the $L/E$ behaviour, and distinguishing effects arising from $\delta_{CP}$ and matter. In this paper we have reevaluated the physics potential of this setup for determining the mass hierarchy (M…
Updated T2K measurements of muon neutrino and antineutrino disappearance using 1.5×1021 protons on target
We report measurements by the T2K experiment of the parameters $\theta_{23}$ and $\Delta m^{2}_{32}$ 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 $7.482 \times 10^{20}$ POT in neutrino running mode and $7.471 \times 10^{20}$ POT in antineutrino mode, T2K obtained, $\sin^{2}(\theta_{23})=0.51^{+0.08}_{-0.07}$ and $\Delta m^{2}_{32} = 2.53^{+0.15}_{-0.13} \times 10^{-3}$eV$^{2}$/c$^{4}$ for neutrinos, and $\sin^{2}({\overline{\theta}}_{23})=0.4…
Measurement of the $\nu_{\mu}$ charged current quasi-elastic cross-section on carbon with the T2K on-axis neutrino beam
17 pages.- 21 figures
Updated Results from the $\nu_{\tau}$ Appearance Search in NOMAD
Updated results from the appearance searches for $\numunutau$ and $\nuenutau$ oscillations in the full NOMAD data sample are reported. The increased data and the use of more refined kinematic schemes for the $\nutau$ CC selection allow a significant improvement of the overall sensitivity. The ``blind analysis" of both the deep-inelastic and the low multiplicity samples yields no evidence for an oscillation signal. In the two-family oscillation scenario, this sets a 90\% C.L. region in the $\sin^22\theta_{\mu\tau} - \Delta m^2$ plane which includes $\sin^22\theta_{\mu\tau}\ <\ 4.4\times10^{-4}$ at large $\Delta m^2$ and $\Delta m^2 < 0.8$ eV$^2$/$c^4$ at $\sin^22\theta_{\mu \tau}=1$. The cor…
Measurement of double-differential muon neutrino charged-current interactions onC8H8without 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 n…
Measurement of the inclusive $\nu_{\mu}$ charged current cross section on iron and hydrocarbon in the T2K on-axis neutrino beam
We report a measurement of the $\nu_\mu$ inclusive charged current cross sections on iron and hydrocarbon in the T2K on-axis neutrino beam. The measured inclusive charged current cross sections on iron and hydrocarbon averaged over the T2K on-axis flux with a mean neutrino energy of 1.51 GeV are $(1.444\pm0.002(stat.)_{-0.157}^{+0.189}(syst.))\times 10^{-38}\mathrm{cm}^2/\mathrm{nucleon}$, and $(1.379\pm0.009(stat.)_{-0.147}^{+0.178}(syst.))\times 10^{-38}\mathrm{cm}^2/\mathrm{nucleon}$, respectively, and their cross section ratio is $1.047\pm0.007(stat.)\pm0.035(syst.)$. These results agree well with the predictions of the neutrino interaction model, and thus we checked the correct treatme…
Inclusive production of ρ0(770), f0(980) and f2(1270) mesons in νμ charged current interactions
The inclusive production of the meson resonances $\rho^{0}(770)$, $f_0(980)$ and $f_2(1270)$ in neutrino-nucleus charged current interactions has been studied with the NOMAD detector exposed to the wide band neutrino beam generated by 450 GeV protons at the CERN SPS. For the first time the $f_{0}(980)$ meson is observed in neutrino interactions. The statistical significance of its observation is 6 standard deviations. The presence of $f_{2}(1270)$ in neutrino interactions is reliably established. The average multiplicity of these three resonances is measured as a function of several kinematic variables. The experimental results are compared to the multiplicities obtained from a simulation b…
Limit on νe→ντ oscillations from the NOMAD experiment
Abstract In the context of a two-flavour approximation we reinterpret the published NOMAD limit on ν μ → ν τ oscillations in terms of ν e → ν τ oscillations. At 90% C.L. we obtain sin 2 2θ eτ 5.2×10 −2 for large Δm 2 , while for sin 2 2 θ eτ =1 the confidence region includes Δm 2 2 / c 4 .
New results on a search for a 33.9 MeV/c2 neutral particle from π+ decay in the NOMAD experiment
We report on a direct search in NOMAD for a new 33.9 MeV/c^2 neutral particle (X) produced in pion decay in flight, pi-->mu_X followed by the decay X -->nu e^+e^-. Both decays are postulated to occur to explain the time anomaly observed by the KARMEN experiment. From the analysis of the data collected during the 1996?1998 runs with 4.1×10^19 protons on target, a single candidate event consistent with background expectations was found. The search is sensitive to a pion branching ratio BR(pi-->muX >3.7×10^-15, significantly smaller than previous experimental limits.
Observation of Electron Neutrino Appearance in a Muon Neutrino Beam
The T2K experiment has observed electron neutrino appearance in a muon neutrino beam produced 295 km from the Super-Kamiokande detector with a peak energy of 0.6 GeV. A total of 28 electron neutrino events were detected with an energy distribution consistent with an appearance signal, corresponding to a significance of 7.3$\sigma$ when compared to 4.92 $\pm$ 0.55 expected background events. In the PMNS mixing model, the electron neutrino appearance signal depends on several parameters including three mixing angles $\theta_{12}$, $\theta_{23}$, $\theta_{13}$, a mass difference $\Delta m^2_{32}$ and a CP violating phase $\delta_{\mathrm{CP}}$. In this neutrino oscillation scenario, assuming $…
Search for Lorentz and CPT violation using sidereal time dependence of neutrino flavor transitions over a short baseline
A class of extensions of the Standard Model allows Lorentz and CPT violations, which can be identified by the observation of sidereal modulations in the neutrino interaction rate. A search for such modulations was performed using the T2K on-axis near detector. Two complementary methods were used in this study, both of which resulted in no evidence of a signal. Limits on associated Lorentz and CPT-violating terms from the Standard Model extension have been derived by taking into account their correlations in this model for the first time. These results imply such symmetry violations are suppressed by a factor of more than 1020 at the GeV scale.
A 4 tonne demonstrator for large-scale dual-phase liquid argon time projection chambers
A 10 kilo-tonne dual-phase liquid argon TPC is one of the detector options considered for the Deep Underground Neutrino Experiment (DUNE). The detector technology relies on amplification of the ionisation charge in ultra-pure argon vapour and offers several advantages compared to the traditional single-phase liquid argon TPCs. A 4.2 tonne dual-phase liquid argon TPC prototype, the largest of its kind, with an active volume of \three has been constructed and operated at CERN. In this paper we describe in detail the experimental setup and detector components as well as report on the operation experience. We also present the first results on the achieved charge amplification, prompt scintillat…
Volume I. Introduction to DUNE
Journal of Instrumentation 15(08), T08008 (1-228) (2020). doi:10.1088/1748-0221/15/08/T08008
Measurement of the polarization in νμ charged current interactions in the NOMAD experiment
The Λ polarization in νμ charged current interactions has been measured in the NOMAD experiment. The event sample (8087 reconstructed Λ 's) is more than an order of magnitude larger than that of previous bubble chamber experiments, while the quality of event reconstruction is comparable. We observe negative polarization along the W -boson direction which is enhanced in the target fragmentation region: Px(xF 0)=−0.09±0.06(stat)±0.03(sys) . These results provide a test of different models describing the nucleon spin composition and the spin transfer mechanisms. A significant transverse polarization (in the direction orthogonal to the Λ production plane) has been observed for the first time in…
Indication of electron neutrino appearance from an accelerator-produced off-axis muon neutrino beam
The T2K experiment observes indications of $\nu_\mu\rightarrow \nu_e$ appearance in data accumulated with $1.43\times10^{20}$ protons on target. Six events pass all selection criteria at the far detector. In a three-flavor neutrino oscillation scenario with $|\Delta m_{23}^2|=2.4\times10^{-3}$ eV$^2$, $\sin^2 2\theta_{23}=1$ and $\sin^2 2\theta_{13}=0$, the expected number of such events is 1.5$\pm$0.3(syst.). Under this hypothesis, the probability to observe six or more candidate events is 7$\times10^{-3}$, equivalent to 2.5$\sigma$ significance. At 90% C.L., the data are consistent with 0.03(0.04)$<\sin^2 2\theta_{13}<$ 0.28(0.34) for $\delta_{\rm CP}=0$ and a normal (inverted) hierarchy.
Measurement of theνμcharged-current quasielastic cross section on carbon with the ND280 detector at T2K
We 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; CEA and CNRS/IN2P3, France; DFG, Germany; INFN, Italy; National Science Centre (NCN), Poland; RSF, RFBR, and MES, Russia; MINECO and ERDF funds, Spain; SNSF and SER, 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 (…
A study of quasi-elastic muon neutrino and antineutrino scattering in the NOMAD experiment
We have studied the muon neutrino and antineutrino quasi-elastic (QEL) scattering reactions ($\nu_\mu n\to \mu^- p$ and $\bar{\nu}_\mu p\to \mu^+ n$) using a set of experimental data collected by the NOMAD collaboration. We have performed measurements of the cross-section of these processes on a nuclear target (mainly Carbon) normalizing it to the total $\nu_\mu$ ($\bar{\nu}_\mu$) charged current cross-section. The results for the flux averaged QEL cross-sections in the (anti)neutrino energy interval 3-100 GeV are $\sigma^{qel}_{\nu_\mu} = (0.92 \pm 0.02 (stat) \pm 0.06 (syst))\times 10^{-38} \cm^2$ and $\sigma{qel}_{\bar{\nu}_\mu} = (0.81 \pm 0.05 (stat) \pm 0.08 (syst))\times 10^{-38} \cm…
First Muon-Neutrino Disappearance Study with an Off-Axis Beam
We report a measurement of muon-neutrino disappearance in the T2K experiment. The 295-km muon-neutrino beam from Tokai to Kamioka is the first implementation of the off-axis technique in a long-baseline neutrino oscillation experiment. With data corresponding to 1.43 × 10(20) protons on target, we observe 31 fully-contained single μ-like ring events in Super-Kamiokande, compared with an expectation of 104 ± 14(syst) events without neutrino oscillations. The best-fit point for two-flavor νμ → ντ oscillations is sin 2(2θ(23)) = 0.98 and |Δm(2)(32)| = 2.65 × 10(−3) eV2. The boundary of the 90% confidence region includes the points (sin2 (2θ(23)), |Δm(2)(32)|) = (1.0, 3.1 × 10(−3) eV2), (0.84, …
Precise measurement of the neutrino mixing parameter θ23 from muon neutrino disappearance in an off-axis beam
New data from the T2K neutrino oscillation experiment produce the most precise measurement of the neutrino mixing parameter theta_{23}. Using an off-axis neutrino beam with a peak energy of 0.6 GeV and a data set corresponding to 6.57 x 10^{20} protons on target, T2K has fit the energy-dependent nu_mu oscillation probability to determine oscillation parameters. Marginalizing over the values of other oscillation parameters yields sin^2 (theta_{23}) = 0.514 +0.055/-0.056 (0.511 +- 0.055), assuming normal (inverted) mass hierarchy. The best-fit mass-squared splitting for normal hierarchy is Delta m^2_{32} = (2.51 +- 0.10) x 10^{-3} eV^2/c^4 (inverted hierarchy: Delta m^2_{13} = (2.48 +- 0.10) …
Study of D*+ production in nu_mu charged current interactions in the NOMAD experiment
A search was made among $\nu_\mu$ charged current events collected in the NOMAD experiment for the reaction: $\nu_\mu + N \rightarrow \mu^- + D^{\star+} + hadrons \hookrightarrow D^0 + \pi^+ \hookrightarrow K^- + \pi^+ A $D^{\star+}$ sample composed of 47 events, with 90% purity, was extracted. The $D^{\star+}$ yield in $\nu_\mu$ charged current interactions was measured to be $T = (0.99 \pm 0.15(stat.) \pm 0.11(syst.))$%. The mean fraction of the hadronic jet energy taken by the $D^{\star+}$ is $0.67 \pm 0.02(stat) \pm 0.02(syst.)$. The distributions of the fragmentation variables $z$, ${P_{T}}^2$ and $x_F$ for $D^{\star+}$ are also presented.
Neutrino production of opposite sign dimuons in the NOMAD experiment
The NOMAD Collaboration presents a study of opposite sign dimuon events in the framework of Leading Order QCD. A total of 2714 neutrino- and 115 antineutrino-induced opposite sign dimuon events with $E_{\mu 1}, E_{\mu 2} > 4.5$ GeV, $15 1\;(\mbox{GeV}/\mbox{c})^{2}$ are observed %in the data from the 1995 and 1996 runs. in the Front-Calorimeter of NOMAD during the 1995 and 1996 runs. The analysis yields a value for the charm quark mass of $m_{c} = 1.3^{+0.3\;+0.3}_{-0.3\;-0.3}\;\mbox{GeV}/\m box{c}^{2}$ and for the average semileptonic branching ratio of $B_{c} = 0.095^{+0.007\;+0.014}_{-0.007\;-0.013}$. The ratio of the strange to non-strange sea in the nucleon is measured to be $\kappa = …
Prediction of neutrino fluxes in the NOMAD experiment
The method developed for the calculation of the flux and composition of the West Area Neutrino Beam used by NOMAD in its search for neutrino oscillations is described. The calculation is based on particle production rates computed using a recent version of FLUKA and modified to take into account the cross sections measured by the SPY and NA20 experiments. These particles are propagated through the beam line taking into account the material and magnetic fields they traverse. The neutrinos produced through their decays are tracked to the NOMAD detector. The fluxes of the four neutrino flavours at NOMAD are predicted with an uncertainty of about 8% for nu(mu) and nu(e), 10% for antinu(mu), and…
Search for a new gauge boson in $\pi^{0}$ decays
A search was made for a new light gauge boson $X$ which might be produced in $\pi^{0}\to\gamma + X$ decay from neutral pions generated by 450-GeV protons in the CERN SPS neutrino target. The X's would penetrate the downstream shielding and be observed in the NOMAD detector via the Primakoff effect, in the process of $X \to\pi^{0}$ conversion in the external Coulomb field of a nucleus. With $1.45\times10^{18}$ protons on target, 20 candidate events with energy between 8 and 140 GeV were found from the analysis of neutrino data. This number is in agreement with the expectation of 18.1$\pm$2.8 background events from standard neutrino processes. A new 90% C.L. upper limit on the branching ratio…
Measurement of the neutrino-oxygen neutral-current interaction cross section by observing nuclear deexcitation gamma rays
We report the first measurement of the neutrino-oxygen neutral-current quasielastic (NCQE) cross section. It is obtained by observing nuclear deexcitation $\gamma$-rays which follow neutrino-oxygen interactions at the Super-Kamiokande water Cherenkov detector. We use T2K data corresponding to $3.01 \times 10^{20}$ protons on target. By selecting only events during the T2K beam window and with well-reconstructed vertices in the fiducial volume, the large background rate from natural radioactivity is dramatically reduced. We observe 43 events in the $4-30$ MeV reconstructed energy window, compared with an expectation of 51.0, which includes an estimated 16.2 background events. The background …
LBNO-DEMO: Large-scale neutrino detector demonstrators for phased performance assessment in view of a long-baseline oscillation experiment
In June 2012, an Expression of Interest for a long-baseline experiment (LBNO) has been submitted to the CERN SPSC. LBNO considers three types of neutrino detector technologies: a double-phase liquid argon (LAr) TPC and a magnetised iron detector as far detectors. For the near detector, a high-pressure gas TPC embedded in a calorimeter and a magnet is the baseline design. A mandatory milestone is a concrete prototyping effort towards the envisioned large-scale detectors, and an accompanying campaign of measurements aimed at assessing the detector associated systematic errors. The proposed $6\times 6\times 6$m$^3$ DLAr is an industrial prototype of the design discussed in the EoI and scalable…
Bose-Einstein correlations in charged current muon-neutrino interactions in the NOMAD experiment at CERN
Bose-Einstein Correlations in one and two dimensions have been studied, with high statistics, in charged current muon-neutrino interaction events collected with the NOMAD detector at CERN. In one dimension the Bose-Einstein effect has been analyzed with the Goldhaber and the Kopylov-Podgoretskii phenomenological parametrizations. The Goldhaber parametrization gives the radius of the pion emission region R_G = 1.01+/-0.05(stat)+0.09-0.06(sys) fm and for the chaoticity parameter the value lambda = 0.40+/-0.03(stat)+0.01-0.06(sys). Using the Kopylov-Podgoretskii parametrization yields R_KP = 2.07+/-0.04(stat)+0.01-0.14(sys) fm and lambda_KP = 0.29+/-0.06(stat)+0.01-0.04(sys). Different paramet…
A precision measurement of charm dimuon production in neutrino interactions from the NOMAD experiment
We present our new measurement of the cross-section for charm dimuon production in neutrino iron interactions based upon the full statistics collected by the NOMAD experiment. After background subtraction we observe 15 344 charm dimuon events, providing the largest sample currently available. The analysis exploits the large inclusive charged current sample - about 9 x 10(6) events after all analysis cuts - and the high resolution NOMAD detector to constrain the total systematic uncertainty on the ratio of charm dimuon to inclusive Charged Current (CC) cross-sections to similar to 2%. We also perform a fit to the NOMAD data to extract the charm production parameters and the strange quark sea…
A precise measurement of the muon neutrino nucleon inclusive charged current cross section off an isoscalar target in the energy range 2.5
Abstract We present a measurement of the muon neutrino–nucleon inclusive charged current cross section, off an isoscalar target, in the neutrino energy range 2.5 ⩽ E ν ⩽ 40 GeV . The significance of this measurement is its precision, ±4% in 2.5 ⩽ E ν ⩽ 10 GeV , and ±2.6% in 10 ⩽ E ν ⩽ 40 GeV regions, where significant uncertainties in previous experiments still exist, and its importance to the current and proposed long baseline neutrino oscillation experiments.
A study of strange particles produced in neutrino neutral current interactions in the NOMAD experiment
Results of a detailed study of strange particle production in neutrino neutral current interactions are presented using the data from the NOMAD experiment. Integral yields of neutral strange particles (K0s, Lambda, Lambda-bar) have been measured. Decays of resonances and heavy hyperons with an identified K0s or Lambda in the final state have been analyzed. Clear signals corresponding to K* and Sigma(1385) have been observed. First results on the measurements of the Lambda polarization in neutral current interactions have been obtained.
A measurement of coherent neutral pion production in neutrino neutral current interactions in the NOMAD experiment
We present a study of exclusive neutral pion production in neutrino-nucleus Neutral Current interactions using data from the NOMAD experiment at the CERN SPS. The data correspond to $1.44 \times 10^6$ muon-neutrino Charged Current interactions in the energy range $2.5 \leq E_{\nu} \leq 300$ GeV. Neutrino events with only one visible $\pi^0$ in the final state are expected to result from two Neutral Current processes: coherent $\pi^0$ production, {\boldmath $\nu + {\cal A} \to \nu + {\cal A} + \pi^0$} and single $\pi^0$ production in neutrino-nucleon scattering. The signature of coherent $\pi^0$ production is an emergent $\pi^0$ almost collinear with the incident neutrino while $\pi^0$'s pro…
Large underground, liquid based detectors for astro-particle physics in Europe: scientific case and prospects
This document reports on a series of experimental and theoretical studies conducted to assess the astro-particle physics potential of three future large-scale particle detectors proposed in Europe as next generation underground observatories. The proposed apparatus employ three different and, to some extent, complementary detection techniques: GLACIER (liquid Argon TPC), LENA (liquid scintillator) and MEMPHYS (\WC), based on the use of large mass of liquids as active detection media. The results of these studies are presented along with a critical discussion of the performance attainable by the three proposed approaches coupled to existing or planned underground laboratories, in relation to…
Measurement of the Inclusive NuMu Charged Current Cross Section on Carbon in the Near Detector of the T2K Experiment
T2K has performed the first measurement of nu(mu) inclusive charged current interactions on carbon at neutrino energies of similar to 1 GeV where the measurement is reported as a flux-averaged double differential cross section in muon momentum and angle. The flux is predicted by the beam Monte Carlo and external data, including the results from the NA61/SHINE experiment. The data used for this measurement were taken in 2010 and 2011, with a total of 10.8 x 10(19) protons-on-target. The analysis is performed on 4485 inclusive charged current interaction candidates selected in the most upstream fine-grained scintillator detector of the near detector. The flux-averaged total cross section is (…
Volume III. DUNE far detector technical coordination
The preponderance of matter over antimatter in the early universe, the dynamics of the supernovae that produced the heavy elements necessary for life, and whether protons eventually decay-these mysteries at the forefront of particle physics and astrophysics are key to understanding the early evolution of our universe, its current state, and its eventual fate. The Deep Underground Neutrino Experiment (DUNE) is an international world-class experiment dedicated to addressing these questions as it searches for leptonic charge-parity symmetry violation, stands ready to capture supernova neutrino bursts, and seeks to observe nucleon decay as a signature of a grand unified theory underlying the st…
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 pπ+>200 MeV/c, pμ>200 MeV/c, cos(θπ+)>0.3 and cos(θμ)>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 ⟨σ⟩ϕ=4.25±0.48(stat)±1.56(syst)×10-40 cm2/nucleon. The total cross section is consistent with the NEUT prediction (5.03×10-40 cm2/nucleon) and 2σ…
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 ~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 $1.11\pm0.09~(stat)\pm0.18~(syst)\times10^{-38} cm^2/nucleon$. The differential and total cross-section measurements agree with the predictions of two leading neutrino interaction generators, NEUT and GENIE. The NEUT prediction is $1.23\times10^{-38} cm^2/nucleon$ and the GENIE prediction is $1.08\times10^{-38} cm^2/nucleon$…
The T2K Experiment
The T2K experiment is a long-baseline neutrino oscillation experiment. Its main goal is to measure the last unknown lepton sector mixing angle {\theta}_{13} by observing {\nu}_e appearance in a {\nu}_{\mu} beam. It also aims to make a precision measurement of the known oscillation parameters, {\Delta}m^{2}_{23} and sin^{2} 2{\theta}_{23}, via {\nu}_{\mu} disappearance studies. Other goals of the experiment include various neutrino cross section measurements and sterile neutrino searches. The experiment uses an intense proton beam generated by the J-PARC accelerator in Tokai, Japan, and is composed of a neutrino beamline, a near detector complex (ND280), and a far detector (Super-Kamiokande)…
Evidence of Electron Neutrino Appearance in a Muon Neutrino Beam
The T2K Collaboration reports evidence for electron neutrino appearance at the atmospheric mass splitting, vertical bar Delta m(32)(2)vertical bar approximate to 2.4 X 10(-3) eV(2). An excess of electron neutrino interactions over background is observed from a muon neutrino beam with a peak energy of 0.6 GeV at the Super-Kamiokande (SK) detector 295 km from the beam's origin. Signal and background predictions are constrained by data from near detectors located 280 m from the neutrino production target. We observe 11 electron neutrino candidate events at the SK detector when a background of 3.3 +/- 0.4(syst) events is expected. The background-only hypothesis is rejected with a p value of 0.0…
Measurement of the single π0 production rate in neutral current neutrino interactions on water
The single π0 production rate in neutral current neutrino interactions on water in a neutrino beam with a peak neutrino energy of 0.6 GeV has been measured using the POD, one of the subdetectors of the T2K near detector. The production rate was measured for data taking periods when the POD contained water (2.64×1020 protons-on-target) and also periods without water (3.49×1020 protons-on-target). A measurement of the neutral current single π0 production rate on water is made using appropriate subtraction of the production rate with water in from the rate with water out of the target region. The subtraction analysis yields 106±41±69 signal events where the uncertainties are statistical (stat.…