Status of MIND

The Magnetised Iron Neutrino Detector (MIND) has been identied as the ideal candidate for the de-tection of the golden \wrong sign muon " channel at a Neutrino Factory. However, previous analyses of the channel relied on a parameterisation of the detector performance which assumed pefect muon pattern recog-nition. For the rst time, a study of the muon reconstruction eciency involvoing full pattern recognition has been carried out. Using a simple pattern recognition algorithm it is shown that past results assuming perfect muon identication can already be reproduced after one simple cut

Performance of the MIND detector at a Neutrino Factory using realistic muon reconstruction

A Neutrino Factory producing an intense beam composed of nu_e(nubar_e) and nubar_mu(nu_mu) from muon decays has been shown to have the greatest sensitivity to the two currently unmeasured neutrino mixing parameters, theta_13 and delta_CP . Using the `wrong-sign muon' signal to measure nu_e to nu_mu(nubar_e to nubar_mu) oscillations in a 50 ktonne Magnetised Iron Neutrino Detector (MIND) sensitivity to delta_CP could be maintained down to small values of theta_13. However, the detector efficiencies used in previous studies were calculated assuming perfect pattern recognition. In this paper, MIND is re-assessed taking into account, for the first time, a realistic pattern recognition for the muon candidate. Reoptimisation of the analysis utilises a combination of methods, including a multivariate analysis similar to the one used in MINOS, to maintain high efficiency while suppressing backgrounds, ensuring that the signal selection efficiency and the background levels are comparable or better than the ones in previous analyses

Future neutrino oscillation facilities

The recent discovery that neutrinos have masses opens a wide new field of experimentation. Accelerator-made neutrinos are essential in this program. Ideas for future facilities include high intensity muon neutrino beams from pion decay (`SuperBeam'), electron neutrino beams from nuclei decays (`Beta Beam'), or muon and electron neutrino beams from muon decay (`Neutrino Factory'), each associated with one or several options for detector systems. Each option offers synergetic possibilities, e.g. some of the detectors can be used for proton decay searches, while the Neutrino Factory is a first step towards muon colliders. A summary of the perceived virtues and shortcomings of the various options, and a number of open questions are presented.Comment: Originally written for the CERN Strategy Grou

Detectors for leptonic CP violation at the neutrino factory

Studies carried out in the framework of the International Design Study for the Neutrino Factory (the IDS-NF) show that the sensitivity to the CP violating phase and the last unknown mixing angle θ13 is maximised when two far detectors optimized to detect the sub-leading νe to νμ oscillation are combined. Several technologies are being discussed for these detectors: magnetised iron calorimeters; giant liquid argon TPCs; and totally active scintillating detectors. The IDS-NF baseline option, a compromise between feasibility, cost, and performance, is documented in the Interim Design Report (IDR) that has recently been completed. It consists of two magnetised iron sampling calorimeters, similar to the existing MINOS detector, but with 10-20 times more mass and improved performance. A detector of mass 100 kton is assumed at the intermediate baseline (between 2500 km and 5000 km) and a 50 kton detector at the long baseline (between 7000 km and 8000 km). The other far-detector options, which have better granularity, may be able to detect additional oscillation channels, thus improving the overall performance of the facility. However, these options are likely to be more expensive and require significant R&D

The Golden Channel at a Neutrino Factory revisited: improved sensitivities from a Magnetised Iron Neutrino Detector

This paper describes the performance and sensitivity to neutrino mixing parameters of a Magnetised Iron Neutrino Detector (MIND) at a Neutrino Factory with a neutrino beam created from the decay of 10 GeV muons. Specifically, it is concerned with the ability of such a detector to detect muons of the opposite sign to those stored (wrong-sign muons) while suppressing contamination of the signal from the interactions of other neutrino species in the beam. A new more realistic simulation and analysis, which improves the efficiency of this detector at low energies, has been developed using the GENIE neutrino event generator and the GEANT4 simulation toolkit. Low energy neutrino events down to 1 GeV were selected, while reducing backgrounds to the $10^{-4}$ level. Signal efficiency plateaus of ~60% for $\nu_\mu$ and ~70% for $\bar{\nu}_\mu$ events were achieved starting at ~5 GeV. Contamination from the $\nu_\mu\rightarrow \nu_\tau$ oscillation channel was studied for the first time and was found to be at the level between 1% and 4%. Full response matrices are supplied for all the signal and background channels from 1 GeV to 10 GeV. The sensitivity of an experiment involving a MIND detector of 100 ktonnes at 2000 km from the Neutrino Factory is calculated for the case of $\sin^2 2\theta_{13}\sim 10^{-1}$. For this value of $\theta_{13}$, the accuracy in the measurement of the CP violating phase is estimated to be $\Delta \delta_{CP}\sim 3^\circ - 5^\circ$, depending on the value of $\delta_{CP}$, the CP coverage at $5\sigma$ is 85% and the mass hierarchy would be determined with better than $5\sigma$ level for all values of $\delta_{CP}$

Toroidal magnetized iron neutrino detector for a neutrino factory

A neutrino factory has unparalleled physics reach for the discovery and measurement of CP violation in the neutrino sector. A far detector for a neutrino factory must have good charge identification with excellent background rejection and a large mass. An elegant solution is to construct a magnetized iron neutrino detector (MIND) along the lines of MINOS, where iron plates provide a toroidal magnetic field and scintillator planes provide 3D space points. In this paper, the current status of a simulation of a toroidal MIND for a neutrino factory is discussed in light of the recent measurements of large θ13. The response and performance using the 10 GeV neutrino factory configuration are presented. It is shown that this setup has equivalent δCP reach to a MIND with a dipole field and is sensitive to the discovery of CP violation over 85% of the values of δCP

Upper bound on neutrino mass based on T2K neutrino timing measurements

The Tokai to Kamioka (T2K) long-baseline neutrino experiment consists of a muon neutrino beam, produced at the J-PARC accelerator, a near detector complex and a large 295-km-distant far detector. The present work utilizes the T2K event timing measurements at the near and far detectors to study neutrino time of flight as a function of derived neutrino energy. Under the assumption of a relativistic relation between energy and time of flight, constraints on the neutrino rest mass can be derived. The sub-GeV neutrino beam in conjunction with timing precision of order tens of ns provide sensitivity to neutrino mass in the few MeV/c(2) range. We study the distribution of relative arrival times of muon and electron neutrino candidate events at the T2K far detector as a function of neutrino energy. The 90% C.L. upper limit on the mixture of neutrino mass eigenstates represented in the data sample is found to be m(v)(2) < 5.6 MeV2/c(4).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 (FP7), EU; JSPS, Japan; Royal Society, UK; DOE Early Career program, USA.Peer reviewe

Testing Matter Effects in Very Long Baseline Neutrino Oscillation Experiments

Assuming three-neutrino mixing, we study the capabilities of very long baseline neutrino oscillation experiments to verify and test the MSW effect and to measure the lepton mixing angle theta_13. We suppose that intense neutrino and antineutrino beams will become available in so-called neutrino factories. We find that the most promising and statistically significant results can be obtained by studying nu_e ->nu_mu and \bar{nu}_e-> \bar{nu}_mu oscillations which lead to matter enhancements and suppressions of wrong sign muon rates. We show the theta_13 ranges where matter effects could be observed as a function of the baseline. We discuss the scaling laws of rates, significances and sensitivities with the relevant mixing angles and experimental parameters. Our analysis includes fluxes, event rates and statistical aspects so that the conclusions should be useful for the planning of experimental setups. We discuss the subleading Delta m^2_{21} effects in the case of the LMA MSW solution of the solar problem, showing that they are small for L >= 7000 km. For shorter baselines, Delta m^2_{21} effects can be relevant and their dependence on L offers a further handle for the determination of the CP-violation phase \delta. Finally we comment on the possibility to measure the specific distortion of the energy spectrum due to the MSW effect.Comment: 30 pages, 13 figures, figures and more discussion added, results and conclusions unchange

Kalman filter tracking and vertexing in a silicon detector for neutrino physics

This article describes the application of Kalman filter techniques for the tracking and vertexing of particles inside the NOMAD-STAR detector a silicon vertex detector installed in NOMAD, one of the neutrino oscillation experiments at the CERN-SPS. The use of the Kalman filter simplifies computationally the tracking and vertex procedure for NOMAD-STAR. The alignment of NOMAD-STAR is shown as an example of the application of the Kalman filter for tracking purposes. The accuracy of the method is such that one obtains alignment residuals between 9 and 12~$\mu$m. Furthermore, a preliminary measure of the impact parameter (with an RMS $\sim 36~\mu$m) illustrates the vertexing capabilities of this technique

The design, construction and performance of the MICE scintillating fibre trackers

This is the Pre-print version of the Article. The official published version can be accessed from the link below - Copyright @ 2011 ElsevierCharged-particle tracking in the international Muon Ionisation Cooling Experiment (MICE) will be performed using two solenoidal spectrometers, each instrumented with a tracking detector based on diameter scintillating fibres. The design and construction of the trackers is described along with the quality-assurance procedures, photon-detection system, readout electronics, reconstruction and simulation software and the data-acquisition system. Finally, the performance of the MICE tracker, determined using cosmic rays, is presented.This work was supported by the Science and Technology Facilities Council under grant numbers PP/E003214/1, PP/E000479/1, PP/E000509/1, PP/E000444/1, and through SLAs with STFC-supported laboratories. This work was also supportedby the Fermi National Accelerator Laboratory, which is operated by the Fermi Research Alliance, under contract No. DE-AC02-76CH03000 with the U.S. Department of Energy, and by the U.S. National Science Foundation under grants PHY-0301737,PHY-0521313, PHY-0758173 and PHY-0630052. The authors also acknowledge the support of the World Premier International Research Center Initiative (WPI Initiative), MEXT, Japan