1,150 research outputs found
Study of the performance of a large scale water-Cherenkov detector (MEMPHYS)
MEMPHYS (MEgaton Mass PHYSics) is a proposed large-scale water Cherenkov
experiment to be performed deep underground. It is dedicated to nucleon decay
searches, neutrinos from supernovae, solar and atmospheric neutrinos, as well
as neutrinos from a future Super-Beam or Beta-Beam to measure the CP violating
phase in the leptonic sector and the mass hierarchy. A full simulation of the
detector has been performed to evaluate its performance for beam physics. The
results are given in terms of "Migration Matrices" of reconstructed versus true
neutrino energy, taking into account all the experimental effects.Comment: Updated after JCAP's referee's comment
Future large-scale water-Cherenkov detector
MEMPHYS (MEgaton Mass PHYSics) is a proposed large-scale water-Cherenkov
experiment to be performed deep underground. It is dedicated to nucleon decay
searches and the detection of neutrinos from supernovae, solar, and atmospheric
neutrinos, as well as neutrinos from a future beam to measure the CP violating
phase in the leptonic sector and the mass hierarchy. This paper provides an
overview of the latest studies on the expected performance of MEMPHYS in view
of detailed estimates of its physics reach, mainly concerning neutrino beams
The OPERA experiment Target Tracker
The main task of the Target Tracker detector of the long baseline neutrino
oscillation OPERA experiment is to locate in which of the target elementary
constituents, the lead/emulsion bricks, the neutrino interactions have occurred
and also to give calorimetric information about each event. The technology used
consists in walls of two planes of plastic scintillator strips, one per
transverse direction. Wavelength shifting fibres collect the light signal
emitted by the scintillator strips and guide it to both ends where it is read
by multi-anode photomultiplier tubes. All the elements used in the construction
of this detector and its main characteristics are described.Comment: 25 pages, submitted to Nuclear Instrument and Method
Determination of the muon charge sign with the dipolar spectrometers of the OPERA experiment
The OPERA long-baseline neutrino-oscillation experiment has observed the
direct appearance of in the CNGS beam. Two large muon
magnetic spectrometers are used to identify muons produced in the
leptonic decay and in interactions by measuring their charge and
momentum. Besides the kinematic analysis of the decays, background
resulting from the decay of charmed particles produced in
interactions is reduced by efficiently identifying the muon track. A new method
for the charge sign determination has been applied, via a weighted angular
matching of the straight track-segments reconstructed in the different parts of
the dipole magnets. Results obtained for Monte Carlo and real data are
presented. Comparison with a method where no matching is used shows a
significant reduction of up to 40\% of the fraction of wrongly determined
charges.Comment: 10 pages. Improvements in the tex
Beams for European Neutrino Experiments (BENE): Midterm scientific report
The activities of BENE during 2004 and 2005 are reviewed. Neutrino oscillation experiments at accelerators offer the richest possibilities of precision studies of neutrino mixing and mass differences, with the potential of important discoveries including leptonic CP or T violation. Two main options for a major initiative have been studied: 1) a high-energy Neutrino Factory coupled to a large dense magnetized detector; 2) a lower energy betabeam and conventional superbeam, coupled to a very large low-density, non-magnetic, detector. Both offer signi cant scienti c breakthroughs over other planned facilities. Much remains to be done to optimize and establish the cost, performance, and feasibility of either solution so as to allow comparison and decision. The proposal of a FP7 Design Study of a Neutrino Facility to be completed by the end of the decade is being prepared. Its success will require strong support and engagement at CERN and other European laboratories and funding agencies. International contributors are already engaged in the framework of an international scoping study. The recommendations and milestones proposed by BENE towards a complete conceptual design are summarized
Procedure for short-lived particle detection in the OPERA experiment and its application to charm decays
The OPERA experiment, designed to perform the first observation of oscillations in appearance mode through the detection of
the leptons produced in charged current interactions, has
collected data from 2008 to 2012. In the present paper, the procedure developed
to detect particle decays, occurring over distances of the order of 1 mm
from the neutrino interaction point, is described in detail. The results of its
application to the search for charmed hadrons are then presented as a
validation of the methods for appearance detection
Limits on muon-neutrino to tau-neutrino oscillations induced by a sterile neutrino state obtained by OPERA at the CNGS beam
The OPERA experiment, exposed to the CERN to Gran Sasso beam,
collected data from 2008 to 2012. Four oscillated Charged Current
interaction candidates have been detected in appearance mode, which are
consistent with oscillations at the atmospheric within the "standard" three-neutrino framework. In this paper, the OPERA
appearance results are used to derive limits on the mixing
parameters of a massive sterile neutrino.Comment: 11 pages, 4 figures; reference to Planck result updated in the
Introduction. Submitted to JHE
Observation of nu_tau appearance in the CNGS beam with the OPERA experiment
The OPERA experiment is searching for nu_mu -> nu_tau oscillations in
appearance mode i.e. via the direct detection of tau leptons in nu_tau charged
current interactions. The evidence of nu_mu -> nu_tau appearance has been
previously reported with three nu_tau candidate events using a sub-sample of
data from the 2008-2012 runs. We report here a fourth nu_tau candidate event,
with the tau decaying into a hadron, found after adding the 2012 run events
without any muon in the final state to the data sample. Given the number of
analysed events and the low background, nu_mu -> nu_tau oscillations are
established with a significance of 4.2sigma.Comment: Submitted to Progress of Theoretical and Experimental Physics (PTEP
Evidence for appearance in the CNGS neutrino beam with the OPERA experiment
The OPERA experiment is designed to search for oscillations in appearance mode i.e. through the direct observation
of the lepton in charged current interactions. The
experiment has taken data for five years, since 2008, with the CERN Neutrino to
Gran Sasso beam. Previously, two candidates with a decaying
into hadrons were observed in a sub-sample of data of the 2008-2011 runs. Here
we report the observation of a third candidate in the
decay channel coming from the analysis of a sub-sample of the
2012 run. Taking into account the estimated background, the absence of
oscillations is excluded at the 3.4
level.Comment: 9 pages, 5 figures, 1 table
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