scholarly journals Long-Baseline Neutrino Oscillation Experiments

2013 ◽  
Vol 2013 ◽  
pp. 1-30 ◽  
Author(s):  
G. J. Feldman ◽  
J. Hartnell ◽  
T. Kobayashi

A review of accelerator long-baseline neutrino oscillation experiments is provided, including all experiments performed to date and the projected sensitivity of those currently in progress. Accelerator experiments have played a crucial role in the confirmation of the neutrino oscillation phenomenon and in precision measurements of the parameters. With a fixed baseline and detectors providing good energy resolution, precise measurements of the ratio of distance/energy (L/E) on the scale of individual events have been made and the expected oscillatory pattern resolved. Evidence for electron neutrino appearance has recently been obtained, opening a door for determining the CP violating phase as well as resolving the mass hierarchy and the octant ofθ23; some of the last unknown parameters of the standard model extended to include neutrino mass.

Universe ◽  
2019 ◽  
Vol 5 (1) ◽  
pp. 21
Author(s):  
Dean Karlen ◽  
on behalf of the TtwoK Collaboration

The T2K long baseline neutrino oscillation experiment measures muon neutrino disappearance and electron neutrino appearance in accelerator-produced neutrino and anti-neutrino beams. This presentation reports on the analysis of our data from an exposure of 2 . 6 × 10 21 protons on target. Results for oscillation parameters, including the CP violation parameter and neutrino mass ordering, are shown.


2018 ◽  
Vol 46 ◽  
pp. 1860038 ◽  
Author(s):  
Erica Smith

The NOvA experiment is a long-baseline accelerator-based neutrino oscillation experiment. It uses the upgraded NuMI beam from Fermilab to measure electron-neutrino appearance and muon-neutrino disappearance between the Near Detector, located at Fermilab, and the Far Detector, located at Ash River, Minnesota. The NuMI beam has recently reached and surpassed the 700 kW power benchmark. NOvA’s primary physics goals include precision measurements of oscillation parameters, such as [Formula: see text] and the atmospheric mass-squared splitting, along with probes of the mass hierarchy and of the CP violating phase. This talk will present the latest NOvA results, based on a neutrino beam exposure equivalent to [Formula: see text] protons-on-target.


2016 ◽  
Vol 3 (2) ◽  
pp. 252-256 ◽  
Author(s):  
Ling Wang ◽  
Mu-ming Poo

Abstract On 8 March 2012, Yifang Wang, co-spokesperson of the Daya Bay Experiment and Director of Institute of High Energy Physics, Chinese Academy of Sciences, announced the discovery of a new type of neutrino oscillation with a surprisingly large mixing angle (θ13), signifying ‘a milestone in neutrino research’. Now his team is heading for a new goal—to determine the neutrino mass hierarchy and to precisely measure oscillation parameters using the Jiangmen Underground Neutrino Observatory, which is due for completion in 2020. Neutrinos are fundamental particles that play important roles in both microscopic particle physics and macroscopic universe evolution. The studies on neutrinos, for example, may answer the question why our universe consists of much more matter than antimatter. But this is not an easy task. Though they are one of the most numerous particles in the universe and zip through our planet and bodies all the time, these tiny particles are like ‘ghost’, difficult to be captured. There are three flavors of neutrinos, known as electron neutrino (νe), muon neutrino (νμ), and tau neutrino (ντ), and their flavors could change as they travel through space via quantum interference. This phenomenon is known as neutrino oscillation or neutrino mixing. To determine the absolute mass of each type of neutrino and find out how they mix is very challenging. In a recent interview with NSR in Beijing, Yifang Wang explained how the Daya Bay Experiment on neutrino oscillation not only addressed the frontier problem in particle physics, but also harnessed the talents and existing technology in Chinese physics community. This achievement, Wang reckons, will not be an exception in Chinese high energy physics, when appropriate funding and organization for big science projects could be efficiently realized in the future.


2019 ◽  
Vol 214 ◽  
pp. 04059
Author(s):  
Marc Paterno ◽  
Jim Kowalkowski ◽  
Saba Sehrish

In their recent measurement of the neutrino oscillation parameters, NOvA uses a sample of approximately 25 million reconstructed spills to search for electron-neutrino appearance events. These events are stored in an n-tuple format, in 250 thousand ROOT files. File sizes range from a few hundred KiB to a few MiB; the full dataset is approximately 1.4 TiB. These millions of events are reduced to a few tens of events by the application of strict event selection criteria, and then summarized by a handful of numbers each, which are used in the extraction of the neutrino oscillation parameters. The NOvA event selection code is currently a serial C++ program that reads these n-tuples. The current table data format and organization and the selection/ reduction processing involved provides us with an opportunity to explore alternate approaches to represent the data and implement the processing. We represent our n-tuple data in HDF5 format that is optimized for the HPC environment and which allows us to use the machine’s high-performance parallel I/O capabilities. We use MPI, numpy and h5py to implement our approach and compare the performance with the existing approach. We study the performance implications of using thousands of small files of different sizes as compared with one large file using HPC resources. This work has been done as part of the SciDAC project, “HEP analytics on HPC” in collaboration with the ASCR teams at ANL and LBNL.


2013 ◽  
Vol 2013 ◽  
pp. 1-29 ◽  
Author(s):  
Silvia Pascoli ◽  
Thomas Schwetz

Recently the last unknown lepton mixing angleθ13has been determined to be relatively large, not too far from its previous upper bound. This opens exciting possibilities for upcoming neutrino oscillation experiments towards addressing fundamental questions, among them the type of the neutrino mass hierarchy and the search for CP violation in the lepton sector. In this paper we review the phenomenology of neutrino oscillations, focusing on subleading effects, which will be the key towards these goals. Starting from a discussion of the present determination of three-flavour oscillation parameters, we give an outlook on the potential of near-term oscillation physics as well as on the long-term program towards possible future precision oscillation facilities. We discuss accelerator-driven long-baseline experiments as well as nonaccelerator possibilities from atmospheric and reactor neutrinos.


Universe ◽  
2020 ◽  
Vol 6 (3) ◽  
pp. 37 ◽  
Author(s):  
Marco Danilo Claudio Torri

This work explores the possibility of resorting to neutrino phenomenology to detect evidence of new physics, caused by the residual signals of the supposed quantum structure of spacetime. In particular, this work investigates the effects on neutrino oscillations and mass hierarchy detection, predicted by models that violate Lorentz invariance, preserving the spacetime isotropy and homogeneity. Neutrino physics is the ideal environment where conducting the search for new “exotic” physics, since the oscillation phenomenon is not included in the original formulation of the minimal Standard Model (SM) of particles. The confirmed observation of the neutrino oscillation phenomenon is, therefore, the first example of physics beyond the SM and can indicate the necessity to resort to new theoretical models. In this work, the hypothesis that the supposed Lorentz Invariance Violation (LIV) perturbations can influence the oscillation pattern is investigated. LIV theories are indeed constructed assuming modified kinematics, caused by the interaction of massive particles with the spacetime background. This means that the dispersion relations are modified, so it appears natural to search for effects caused by LIV in physical phenomena governed by masses, as in the case of neutrino oscillations. In addition, the neutrino oscillation phenomenon is interesting since there are three different mass eigenstates and in a LIV scenario, which preserves isotropy, at least two different species of particle must interact.


2008 ◽  
Vol 23 (21) ◽  
pp. 3388-3394
Author(s):  
HISAKAZU MINAKATA

I discuss why and how powerful is the two-detector setting in neutrino oscillation experiments. I cover three concrete examples: (1) reactor θ13 experiments, (2) T2KK, Tokai-to-Kamioka-Korea two-detector complex for measuring CP violation, determining the neutrino mass hierarchy, and resolving the eight-fold parameter degeneracy, (3) two-detector setting in a neutrino factory at baselines 3000 km and 7000 km for detecting effects of non-standard interactions (NSI) of neutrinos.


2019 ◽  
Vol 64 (7) ◽  
pp. 613
Author(s):  
T. Nosek

NOvA is a two-detector long-baseline neutrino oscillation experiment using Fermilab’s 700 kW NuMI muon neutrino beam. With a total exposure of 8.85×1020 +12.33×1020 protons on target delivered to NuMI in the neutrino + antineutrino beam mode (78% more antineutrino data than in 2018), the experiment has made a 4.4q-significant observation of the ve appearance in a vм beam, measured oscillation parameters |Δm232|, sin2O23, and excluded most values near бCP = п/2 for the inverted neutrino mass hierarchy by more than 3q.


2016 ◽  
Vol 2016 ◽  
pp. 1-17
Author(s):  
M. G. Catanesi

This paper presents thestate of the artof the T2K experiment and the measurements prospects for the incoming years. After a brief description of the experiment, the most recent results will be illustrated. The observation of the electron neutrino appearance in a muon neutrino beam and the new high-precision measurements of the mixing angleθ13by the reactor experiments have led to a reevaluation of the expected sensitivity to the oscillation parameters, relative to what was given in the original T2K proposal. For this reason the new physics potential of T2K for7.8×1021p.o.t. and for data exposure 3 times larger than that expected to be reachable with accelerator and beam line upgrades in 2026 before the start of operation of the next generation of long-baseline neutrino oscillation experiments will also be described in the text. In particular the last challenging scenario opens the door to the possibility of obtaining, under some conditions, a 3σmeasurement excludingsin⁡(δCP)=0.


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