423 research outputs found
Neutral Current Production in MiniBooNE
This paper describes the analysis used to determine the neutral current
production in MiniBooNE in bins of momentum. Additionally, a
measurement of the relative coherent production of s is discussed. The
coherent production rate is found to be (19.5 1.1 (stat) 2.5 (sys))%
of the total exclusive neutral current production rate.Comment: Prepared for the Proceedings of Neutrino Interactions 200
Pion Production in Neutrino-Nucleon Reactions
We construct a model for the weak pion production off the nucleon, which in
addition to the weak excitation of the resonance and its
subsequent decay into , it includes also some background terms required
by chiral symmetry. We re-fit the form factor to the flux averaged
ANL differential cross section data, finding
a substantially smaller contribution of the pole mechanism than
traditionally assumed in the literature. We also show that the interference
between the Delta pole and the background terms produces parity-violating
contributions to the pion angular differential cross section.Comment: To appear in the proceedings of Fifth International Workshop on.
Neutrino-Nucleus Interactions in the Few-GeV Region. May 30, 2007 - June 3,
2007. Fermilab, Batavia, Illinois US
Nuclear corrections in neutrino-nucleus DIS and their compatibility with global NPDF analyses
We perform a global chi^2-analysis of nuclear parton distribution functions
using data from charged current neutrino-nucleus deep-inelastic scattering
(DIS), charged-lepton-nucleus DIS, and the Drell-Yan (DY) process. We show that
the nuclear corrections in nu-A DIS are not compatible with the predictions
derived from l^+A DIS and DY data. We quantify this result using a
hypothesis-testing criterion based on the chi^2 distribution which we apply to
the total chi^2 as well as to the chi^2 of the individual data sets. We find
that it is not possible to accommodate the data from nu-A and l^+A DIS by an
acceptable combined fit. Our result has strong implications for the extraction
of both nuclear and proton parton distribution functions using combined
neutrino and charged-lepton data sets.Comment: 5 page
Thermal shot noise in top-gated single carbon nanotube field effect transistors
The high-frequency transconductance and current noise of top-gated single
carbon nanotube transistors have been measured and used to investigate hot
electron effects in one-dimensional transistors. Results are in good agreement
with a theory of 1-dimensional nano-transistor. In particular the prediction of
a large transconductance correction to the Johnson-Nyquist thermal noise
formula is confirmed experimentally. Experiment shows that nanotube transistors
can be used as fast charge detectors for quantum coherent electronics with a
resolution of in the 0.2- band.Comment: 3 pages, 4 figure
A relativistic model for neutrino pion production from nuclei in the resonance region
We present a relativistic model for electroweak pion production from nuclei,
focusing on the and the second resonance region. Bound states are
derived in the Hartree approximation to the Walecka model.
Final-state interactions of the outgoing pion and nucleon are described in a
factorized way by means of a relativistic extension of the Glauber model. Our
formalism allows a detailed study of neutrino pion production through ,
, energy, angle and out-of-plane distributions.Comment: 3 pages, 1 figure, poster presented at the NuInt07 conference on
few-GeV neutrino physic
Shot noise in carbon nanotube based Fabry-Perot interferometers
We report on shot noise measurements in carbon nanotube based Fabry-Perot
electronic interferometers. As a consequence of quantum interferences, the
noise power spectral density oscillates as a function of the voltage applied to
the gate electrode. The quantum shot noise theory accounts for the data
quantitatively. It allows to confirm the existence of two nearly degenerate
orbitals. At resonance, the transmission of the nanotube approaches unity, and
the nanotube becomes noiseless, as observed in quantum point contacts. In this
weak backscattering regime, the dependence of the noise on the backscattering
current is found weaker than expected, pointing either to electron-electron
interactions or to weak decoherence
Nuclear parton distribution functions and their uncertainties
We analyze experimental data of nuclear structure-function ratios
F_2^A/F_2^{A'} and Drell-Yan cross section ratios for obtaining optimum parton
distribution functions (PDFs) in nuclei. Then, uncertainties of the nuclear
PDFs are estimated by the Hessian method. Valence-quark distributions are
determined by the F_2 data at large x; however, the small-x part is not obvious
from the data. On the other hand, the antiquark distributions are determined
well at x~0.01 from the F_2 data and at x~0.1 by the Drell-Yan data; however,
the large-x behavior is not clear. Gluon distributions cannot be fixed by the
present data and they have large uncertainties in the whole x region.
Parametrization results are shown in comparison with the data. We provide a
useful code for calculating nuclear PDFs at given x and Q^2.Comment: 9 pages, REVTeX, 23 eps files, Phys. Rev. C in press. Nuclear PDF
library is available at http://hs.phys.saga-u.ac.jp/nuclp.htm
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Proposal to perform a high - statistics neutrino scattering experiment using a fine - grained detector in the NuMI Beam
The NuMI facility at Fermilab will provide an extremely intense beam of neutrinos for the MINOS neutrino-oscillation experiment. The spacious and fully-outfitted MINOS near detector hall will be the ideal venue for a high-statistics, high-resolution {nu} and {bar {nu}}-nucleon/nucleus scattering experiment. The experiment described here will measure neutrino cross-sections and probe nuclear effects essential to present and future neutrino-oscillation experiments. Moreover, with the high NuMI beam intensity, the experiment will either initially address or significantly improve our knowledge of a wide variety of neutrino physics topics of interest and importance to the elementary-particle and nuclear-physics communities
nCTEQ15 - Global analysis of nuclear parton distributions with uncertainties in the CTEQ framework
We present the new nCTEQ15 set of nuclear parton distribution functions with
uncertainties. This fit extends the CTEQ proton PDFs to include the nuclear
dependence using data on nuclei all the way up to 208^Pb. The uncertainties are
determined using the Hessian method with an optimal rescaling of the
eigenvectors to accurately represent the uncertainties for the chosen tolerance
criteria. In addition to the Deep Inelastic Scattering (DIS) and Drell-Yan (DY)
processes, we also include inclusive pion production data from RHIC to help
constrain the nuclear gluon PDF. Furthermore, we investigate the correlation of
the data sets with specific nPDF flavor components, and asses the impact of
individual experiments. We also provide comparisons of the nCTEQ15 set with
recent fits from other groups.Comment: 35 page
Conserved spin and orbital phase along carbon nanotubes connected with multiple ferromagnetic contacts
We report on spin dependent transport measurements in carbon nanotubes based
multi-terminal circuits. We observe a gate-controlled spin signal in non-local
voltages and an anomalous conductance spin signal, which reveal that both the
spin and the orbital phase can be conserved along carbon nanotubes with
multiple ferromagnetic contacts. This paves the way for spintronics devices
exploiting both these quantum mechanical degrees of freedom on the same
footing.Comment: 8 pages - minor differences with published versio
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