11 research outputs found
Nuclear effects in neutrino-nucleus interactions
An accurate description of the nuclear response functions for neutrino
scattering in the Gev region is essential for the interpretation of present and
future neutrino oscillation experiments. Due to the close similarity of
electromagnetic and weak scattering processes, we will review the status of the
scaling approach and of relativistic modeling for the inclusive electron
scattering response functions in the quasielastic and -resonance
regions. In particular, recent studies have been focused on scaling violations
and the degree to which these imply modifications of existing predictions for
neutrino reactions. We will discuss sources and magnitude of such violations,
emphasizing similarities and differences between electron and neutrino
reactions.Comment: 7 pages, 5 figures, Proceeding of the XVIII International School on
Nuclear Physics, Neutron Physics and Applications, September 21 - 27, 2009
Varna, Bulgari
Status and perspectives of short baseline studies
The study of flavor changing neutrinos is a very active field of research. I
will discuss the status of ongoing and near term experiments investigating
neutrino properties at short distances from the source. In the next few years,
the Double Chooz, RENO and Daya Bay reactor neutrino experiments will start
looking for signatures of a non-zero value of the mixing angle
with much improved sensitivities. The MiniBooNE experiment is investigating the
LSND anomaly by looking at both the and
appearance channels. Recent results on
cross section measurements will be discussed briefly.Comment: 6 pages, 2 figures, to appear in the proceedings of the 11th
International Conference on Topics in Astroparticle and Underground Physics
(TAUP 2009), Rome, Italy, 1-5 July 200
First Measurement of Monoenergetic Muon Neutrino Charged Current Interactions
We report the first measurement of monoenergetic muon neutrino charged
current interactions. MiniBooNE has isolated 236 MeV muon neutrino events
originating from charged kaon decay at rest ()
at the NuMI beamline absorber. These signal -carbon events are
distinguished from primarily pion decay in flight and
backgrounds produced at the target station and decay pipe
using their arrival time and reconstructed muon energy. The significance of the
signal observation is at the 3.9 level. The muon kinetic energy,
neutrino-nucleus energy transfer (), and total cross
section for these events is extracted. This result is the first known-energy,
weak-interaction-only probe of the nucleus to yield a measurement of
using neutrinos, a quantity thus far only accessible through electron
scattering.Comment: 6 pages, 4 figure
A Search for Electron Antineutrino Appearance at the 1 Scale
The MiniBooNE Collaboration reports initial results from a search for
oscillations. A signal-blind analysis was
performed using a data sample corresponding to protons on
target. The data are consistent with background prediction across the full
range of neutrino energy reconstructed assuming quasielastic scattering, MeV: 144 electron-like events have been observed in this
energy range, compared to an expectation of events. No
significant excess of events has been observed, both at low energy, 200-475
MeV, and at high energy, 475-1250 MeV. The data are inconclusive with respect
to antineutrino oscillations suggested by data from the Liquid Scintillator
Neutrino Detector at Los Alamos National Laboratory.Comment: 5 pages, 3 figures, 2 table
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
A search for muon neutrino and antineutrino disappearance in MiniBooNE
The MiniBooNE Collaboration reports a search for \numu and \numubar
disappearance in the \dmsq region of a few \evsq. These measurements are
important for constraining models with extra types of neutrinos, extra
dimensions an d CPT violation. Fits to the shape of the \numu and \numubar
energy spectra reveal no evidence for disappearance at 90% confidence level
(CL) in either mode. This is the first test of \numubar disappearance between
\dmsq=0.1-10\evsq.Comment: 10 pages, 3 figures, submitted to PR
The MiniBooNE Detector
The MiniBooNE neutrino detector was designed and built to look for
muon-neutrino to electron-neutrino oscillations in the mixing parameter space
region where the LSND experiment reported a signal. The MiniBooNE experiment
used a beam energy and baseline that were an order of magnitude larger than
those of LSND so that the backgrounds and systematic errors would be completely
different. This paper provides a detailed description of the design, function,
and performance of the MiniBooNE detector.Comment: 46 pages, 21 figure
First Measurement of Monoenergetic Muon Neutrino Charged Current Interactions
We report the first measurement of monoenergetic muon neutrino charged current interactions. MiniBooNE has isolated 236 MeV muon neutrino events originating from charged kaon decay at rest (K+→μ+νμ) at the NuMI beamline absorber. These signal νμ-carbon events are distinguished from primarily pion decay in flight νμ and ¯νμ backgrounds produced at the target station and decay pipe using their arrival time and reconstructed muon energy. The significance of the signal observation is at the 3.9σ level. The muon kinetic energy, neutrino-nucleus energy transfer (ω=Eν−Eμ), and total cross section for these events are extracted. This result is the first known-energy, weak-interaction-only probe of the nucleus to yield a measurement of ω using neutrinos, a quantity thus far only accessible through electron scattering
Improved Search for ν̅ [subscript μ]→ν̅ [subscript e] Oscillations in the MiniBooNE Experiment
The MiniBooNE experiment at Fermilab reports results from an analysis of ν̅ [subscript e] appearance data from 11.27×10[superscript 20] protons on target in the antineutrino mode, an increase of approximately a factor of 2 over the previously reported results. An event excess of 78.4±28.5 events (2.8σ) is observed in the energy range 200<E[subscript ν][superscript QE]<1250  MeV. If interpreted in a two-neutrino oscillation model, ν̅ [subscript μ]→ν̅ [subscript e] , the best oscillation fit to the excess has a probability of 66% while the background-only fit has a χ[superscript 2] probability of 0.5% relative to the best fit. The data are consistent with antineutrino oscillations in the 0.01<Δm[superscript 2]<1.0  eV[superscript 2] range and have some overlap with the evidence for antineutrino oscillations from the Liquid Scintillator Neutrino Detector. All of the major backgrounds are constrained by in situ event measurements so nonoscillation explanations would need to invoke new anomalous background processes. The neutrino mode running also shows an excess at low energy of 162.0±47.8 events (3.4σ) but the energy distribution of the excess is marginally compatible with a simple two neutrino oscillation formalism. Expanded models with several sterile neutrinos can reduce the incompatibility by allowing for CP violating effects between neutrino and antineutrino oscillations. © 2013 American Physical SocietyUnited States. Dept. of EnergyNational Science Foundation (U.S.)Fermi National Accelerator Laborator
Dual baseline search for muon antineutrino disappearance at 0.1 eV² < <{\Delta}m² < 100 eV²
The MiniBooNE and SciBooNE collaborations report the results of a joint search for short baseline disappearance of ν̅[subscript μ] at Fermilab’s Booster Neutrino Beamline. The MiniBooNE Cherenkov detector and the SciBooNE tracking detector observe antineutrinos from the same beam, therefore the combined analysis of their data sets serves to partially constrain some of the flux and cross section uncertainties. Uncertainties in the ν[subscript μ] background were constrained by neutrino flux and cross section measurements performed in both detectors. A likelihood ratio method was used to set a 90% confidence level upper limit on ν̅[subscript μ] disappearance that dramatically improves upon prior limits in the Δm[superscript 2]=0.1–100  eV[superscript 2] region