661 research outputs found
Overview of progress in neutrino scattering measurements
Recent progress in neutrino scattering experiments with few GeV neutrino
beams is reviewed, focusing on new experimental input since the beginning of
the NuInt workshop series in 2001. Progress in neutrino quasi-elastic
scattering, resonance production, coherent pion production, scattering in the
transition region between the resonance and deep inelastic regimes, and nuclear
effects in neutrino-nucleus scattering, is discussed.Comment: To appear in the proceedings of 5th International Workshop on
Neutrino-Nucleus Interactions in the Few-GeV Region (NuInt07), Batavia,
Illinois, 30 May - 3 Jun 2007. Submitted to AIP Conf.Pro
Understanding the Forward Muon Deficit in Coherent Pion Production
For any inelastic process with ,
the cross section at is given by Adler's PCAC theorem.
Inclusion of the lepton mass has a dynamical effect (``PCAC-screening'') caused
by interference of spin-zero () and spin-one exchanges. This effect may
be relevant to the forward suppression reported in recent experiments.Comment: 3 pages, 2 figures, presented at NuInt07, Fermilab, may 31 - june 3
200
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
Spectral functions for medium-sized nuclei
The spectral functions for calcium and argon are constructed. It is verified
that their predictions for the quasielastic electron-nucleus cross sections in
the energy range ~1 GeV agree with the data. The argon spectral function is
then used to obtain the quasielastic neutrino-nucleus cross section.Comment: 3 pages, 3 figures, presented at 5th International Workshop on
Neutrino-Nucleus Interactions in the Few-GeV Region (NuInt07), Fermilab, USA,
30.05-3.06.200
Single Pion production from Nuclei
We have studied charged current one pion production induced by
from some nuclei. The calculations have been done for
the incoherent pion production processes from these nuclear targets in the
dominance model and take into account the effect of Pauli blocking,
Fermi motion and renormalization of properties in the nuclear medium.
The effect of final state interactions of pions has also been taken into
account. The numerical results have been compared with the recent results from
the MiniBooNE experiment for the charged current 1 production, and also
with some of the older experiments in Freon and Freon-Propane from CERN.Comment: 5 pages, 5 figures, 5th International Workshop on Neutrino-Nucleus
Interactions in the few GeV region(NuInt07), Batavia, Illinois, 30May-3June,
200
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
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
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