4 research outputs found
T2K Results and Future Plans
We present the numu to nue appearance and the numu disappearance results,
using a total of 1.43 x 10^{20} protons on target collected with the T2K
experiment. T2K is long baseline neutrino experiment in Japan with detectors
located at J-PARC, Tokai, and at Kamioka in the Gifu Prefecture, situated 295
km away from J-PARC. The muon neutrino beam is produced and measured at the
near detectors at J-PARC whilst the neutrino rates after oscillation are
measured with the Super-Kamiokande detector, at Kamioka. A total of six events
pass all the selection criteria for numu to nue oscillations at the far
detector Super-Kamiokande, leading to 0.03(0.04) < sin^2 2theta_{13} <
0.28(0.34) for deltaCP = 0 and normal (inverted) hierarchy at 90% C.L. The numu
disappearance analysis excludes no oscillations at 4.3 sigma. At 90% C.L., the
best fit values are sin^2 2theta_{23} > 0.84 and 2.1 x 10^{-3} < Delta m^2_{23}
(eV^2) < 3.1 x 10^{-3}. Finally, we present an overview of the T2K plans from
2011 onwards.Comment: Contribution to NUFACT 11, XIIIth International Workshop on Neutrino
Factories, Super beams and Beta beams, 1-6 August 2011, CERN and University
of Geneva (Submitted to IOP conference series). 8 pages, 7 postscript figure
Neutrino-nucleus cross sections for oscillation experiments
Neutrino oscillations physics is entered in the precision era. In this
context accelerator-based neutrino experiments need a reduction of systematic
errors to the level of a few percent. Today one of the most important sources
of systematic errors are neutrino-nucleus cross sections which in the
hundreds-MeV to few-GeV energy region are known with a precision not exceeding
20%. In this article we review the present experimental and theoretical
knowledge of the neutrino-nucleus interaction physics. After introducing
neutrino oscillation physics and accelerator-based neutrino experiments, we
overview general aspects of the neutrino-nucleus cross sections, both
theoretical and experimental views. Then we focus on these quantities in
different reaction channels. We start with the quasielastic and
quasielastic-like cross section, putting a special emphasis on multinucleon
emission channel which attracted a lot of attention in the last few years. We
review the main aspects of the different microscopic models for this channel by
discussing analogies and differences among them.The discussion is always driven
by a comparison with the experimental data. We then consider the one pion
production channel where data-theory agreement remains very unsatisfactory. We
describe how to interpret pion data, then we analyze in particular the puzzle
related to the impossibility of theoretical models and Monte Carlo to
simultaneously describe MiniBooNE and MINERvA experimental results. Inclusive
cross sections are also discussed, as well as the comparison between the
and cross sections, relevant for the CP violation
experiments. The impact of the nuclear effects on the reconstruction of
neutrino energy and on the determination of the neutrino oscillation parameters
is reviewed. A window to the future is finally opened by discussing projects
and efforts in future detectors, beams, and analysis
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Long baseline neutrino oscillation experiment at the AGS. Physics design report
The authors present a design for a multi-detector long baseline neutrino oscillation experiment at the BNL AGS. It has been approved by the BNL-HENP-PAC as AGS Experiment 889. The experiment will search for oscillations in the {nu}{sub {mu}}, disappearance channel and the {nu}{sub {mu}} {leftrightarrow} {nu}{sub e} appearance channel by means of four identical neutrino detectors located 1, 3, 24, and 68km from the AGS neutrino source. Observed depletion of the {nu}{sub {mu}} flux (via quasi-elastic muon neutrino events, {nu}{sub {mu}}n {yields} {mu}{sup {minus}}p) in the far detectors not attended by an observed proportional increase of the {nu}{sub e} flux (via quasi-elastic electron neutrino events, {nu}{sub e}n {yields} e{sup {minus}}p) in those detectors will be prima facie evidence for the oscillation channel {nu}{sub {mu}} {leftrightarrow} {nu}{sub {tau}}. The experiment is directed toward exploration of the region of the neutrino oscillation parameters {Delta}m{sup 2} and sin{sup 2}2{theta}, suggested by the Kamiokande and IMB deep underground detectors but it will also explore a region more than two orders of magnitude larger than that of previous accelerator experiments. The experiment will run in a mode new to BNL. It will receive the fast extracted proton beam on the neutrino target approximately 20 hours per day when the AGS is not filling RHIC. A key aspect of the experimental design involves placing the detectors 1.5 degrees off the center line of the neutrino beam, which has the important advantage that the central value of the neutrino energy ({approx} 1 GeV) and the beam spectral shape are, to a good approximation, the same in all four detectors. The proposed detectors are massive, imaging, water Cherenkov detectors similar in large part to the Kamiokande and IMB detectors. The design has profited from their decade-long experience, and from the detector designs of the forthcoming SNO and SuperKamiokande detectors