471 research outputs found
Quasielastic Scattering at MiniBooNE Energies
We present our description of neutrino induced charged current quasielastic
scattering (CCQE) in nuclei at energies relevant for the MiniBooNE experiment.
In our framework, the nucleons, with initial momentum distributions according
to the Local Fermi Gas model, move in a density- and momentum-dependent mean
field potential. The broadening of the outgoing nucleons due to nucleon-nucleon
interactions is taken into account by spectral functions. Long range (RPA)
correlations renormalizing the electroweak strength in the medium are also
incorporated. The background from resonance excitation events that do not lead
to pions in the final state is also predicted by propagating the outgoing
hadrons with the Giessen semiclassical BUU model in coupled channels (GiBUU).
We achieve a good description of the shape of the CCQE Q2 distribution
extracted from data by MiniBooNE, thanks to the inclusion of RPA correlations,
but underestimate the integrated cross section when the standard value of MA =
1 GeV is used. Possible reasons for this mismatch are discussed.Comment: 6 pages, 4 figures, Proceedings of the Sixth International Workshop
on Neutrino-Nucleus Interactions in the Few-GeV Region (NuInt09), May 18-22,
Sitges, Barcelona, Spai
Neutrino induced pion production at MiniBooNE and K2K energies
We investigate charged and neutral current neutrino-induced incoherent pion
production off nuclei within the GiBUU model at energies relevant for the
MiniBooNE and K2K experiments. Special attention is paid to the entanglement
between measured CCQE and CC1pi+ cross sections. We further give predictions
and compare to recent data measured at MiniBooNE.Comment: To appear in the proceedings of 6th International Workshop on
Neutrino-Nucleus Interactions in the Few-GeV Region (NuInt09), Sitges, Spain,
18 - 22 May 200
Modeling Resolution of Resources Contention in Synchronous Data Flow Graphs
Synchronous Data Flow graphs are widely adopted in the designing of streaming applications, but were originally formulated to describe only how an application is partitioned and which data are exchanged among different tasks. Since Synchronous Data Flow graphs are often used to describe and evaluate complete design solutions, missing information (e.g., mapping, scheduling, etc.) has to be included in them by means of further actors and channels to obtain accurate evaluations. To address this issue preserving the simplicity of the representation, techniques that model data transfer delays by means of ad-hoc actors have been proposed, but they model independently each communication ignoring contentions. Moreover, they do not usually consider at all delays due to buffer contentions, potentially overestimating the throughput of a design solution. In this paper a technique to extend Synchronous Data Flow graphs by adding ad-hoc actors and channels to model resolution of resources contentions is proposed. The results show that the number of added actors and channels is limited but that they can significantly increase the Synchronous Data Flow graph accuracy
A combined analysis of short-baseline neutrino experiments in the (3+1) and (3+2) sterile neutrino oscillation hypotheses
We investigate adding two sterile neutrinos to resolve the apparent tension
existing between short-baseline neutrino oscillation results and
CPT-conserving, four-neutrino oscillation models. For both (3+1) and (3+2)
models, the level of statistical compatibility between the combined dataset
from the null short-baseline experiments Bugey, CHOOZ, CCFR84, CDHS, KARMEN,
and NOMAD, on the one hand; and the LSND dataset, on the other, is computed. A
combined analysis of all seven short-baseline experiments, including LSND, is
also performed, to obtain the favored regions in neutrino mass and mixing
parameter space for both models. Finally, four statistical tests to compare the
(3+1) and the (3+2) hypotheses are discussed. All tests show that (3+2) models
fit the existing short-baseline data significantly better than (3+1) models.Comment: 16 pages, 15 figures. Added NOMAD data to the analysis, one
statistical test, and two figures. References and text added. Version
submitted to PR
High-powEr Phosphorous-based DFB Lasers for Cold Atom Systems (HELCATS)
No abstract available
A new, very massive modular Liquid Argon Imaging Chamber to detect low energy off-axis neutrinos from the CNGS beam. (Project MODULAr)
The paper is considering an opportunity for the CERN/GranSasso (CNGS)
neutrino complex, concurrent time-wise with T2K and NOvA, to search for
theta_13 oscillations and CP violation. Compared with large water Cherenkov
(T2K) and fine grained scintillators (NOvA), the LAr-TPC offers a higher
detection efficiency and a lower backgrounds, since virtually all channels may
be unambiguously recognized. The present proposal, called MODULAr, describes a
20 kt fiducial volume LAr-TPC, following very closely the technology developed
for the ICARUS-T60o, and is focused on the following activities, for which we
seek an extended international collaboration:
(1) the neutrino beam from the CERN 400 GeV proton beam and an optimised horn
focussing, eventually with an increased intensity in the framework of the LHC
accelerator improvement program;
(2) A new experimental area LNGS-B, of at least 50000 m3 at 10 km off-axis
from the main Laboratory, eventually upgradable to larger sizes. A location is
under consideration at about 1.2 km equivalent water depth;
(3) A new LAr Imaging detector of at least 20 kt fiducial mass. Such an
increase in the volume over the current ICARUS T600 needs to be carefully
considered. It is concluded that a very large mass is best realised with a set
of many identical, independent units, each of 5 kt, "cloning" the technology of
the T600. Further phases may foresee extensions of MODULAr to meet future
physics goals.
The experiment might reasonably be operational in about 4/5 years, provided a
new hall is excavated in the vicinity of the Gran Sasso Laboratory and adequate
funding and participation are made available.Comment: Correspondig Author: C. Rubbia (E-mail: [email protected]), 33
pages, 11 figure
Measurement of Muon Neutrino Quasi-Elastic Scattering on Carbon
The observation of neutrino oscillations is clear evidence for physics beyond
the standard model. To make precise measurements of this phenomenon, neutrino
oscillation experiments, including MiniBooNE, require an accurate description
of neutrino charged current quasi-elastic (CCQE) cross sections to predict
signal samples. Using a high-statistics sample of muon neutrino CCQE events,
MiniBooNE finds that a simple Fermi gas model, with appropriate adjustments,
accurately characterizes the CCQE events observed in a carbon-based detector.
The extracted parameters include an effective axial mass, M_A^eff = 1.23+/-0.20
GeV, that describes the four-momentum dependence of the axial-vector form
factor of the nucleon; and a Pauli-suppression parameter, kappa =
1.019+/-0.011. Such a modified Fermi gas model may also be used by future
accelerator-based experiments measuring neutrino oscillations on nuclear
targets.Comment: 5 pages, 3 figure
Measurement of the neutrino component of an anti-neutrino beam observed by a non-magnetized detector
Two independent methods are employed to measure the neutrino flux of the
anti-neutrino-mode beam observed by the MiniBooNE detector. The first method
compares data to simulated event rates in a high purity \numu induced
charged-current single \pip (CC1\pip) sample while the second exploits the
difference between the angular distributions of muons created in \numu and
\numub charged-current quasi-elastic (CCQE) interactions. The results from
both analyses indicate the prediction of the neutrino flux component of the
pre-dominately anti-neutrino beam is over-estimated - the CC1\pip analysis
indicates the predicted \numu flux should be scaled by , while
the CCQE angular fit yields . The energy spectrum of the flux
prediction is checked by repeating the analyses in bins of reconstructed
neutrino energy, and the results show that the spectral shape is well modeled.
These analyses are a demonstration of techniques for measuring the neutrino
contamination of anti-neutrino beams observed by future non-magnetized
detectors.Comment: 15 pages, 7 figures, published in Physical Review D, latest version
reflects changes from referee comment
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