245 research outputs found
Single photon events from neutral current interactions at MiniBooNE
The MiniBooNE experiment has reported results from the analysis of
and appearance searches, which show an excess of signal-like
events at low reconstructed neutrino energies, with respect to the expected
background. A significant component of this background comes from photon
emission induced by (anti)neutrino neutral current interactions with nucleons
and nuclei. With an improved microscopic model for these reactions, we predict
the number and distributions of photon events at the MiniBooNE detector. Our
results are compared to the MiniBooNE in situ estimate and to other theoretical
approaches. We find that, according to our model, neutral current photon
emission from single-nucleon currents is insufficient to explain the events
excess observed by MiniBooNE in both neutrino and antineutrino modes.Comment: 10 pages, 8 figures; error analysis improved; accepted in PL
Watson's theorem and the axial transition
We present a new determination of the axial form factors from
neutrino induced pion production data. For this purpose, the model of Hernandez
{\it et al.} [Phys. Rev. D76, 033005 (2007)] is improved by partially restoring
unitarity. This is accomplished by imposing Watson's theorem on the dominant
vector and axial multipoles. As a consequence, a larger , in good
agreement with the prediction from the off-diagonal Goldberger-Treiman
relation, is now obtained.Comment: 17 latex pages, 7 figures, 2 tables. Some typos correcte
Charged-Current Neutral Pion production at SciBooNE
SciBooNE, located in the Booster Neutrino Beam at Fermilab, collected data
from June 2007 to August 2008 to accurately measure muon neutrino and
anti-neutrino cross sections on carbon below 1 GeV neutrino energy. SciBooNE is
studying charged current interactions. Among them, neutral pion production
interactions will be the focus of this poster. The experimental signature of
neutrino-induced neutral pion production is constituted by two electromagnetic
cascades initiated by the conversion of the neutral pion decay photons, with an
additional muon in the final state for CC processes.
In this poster, I will present how we reconstruct and select charged-current
muon neutrino interactions producing neutral pions in SciBooNE.Comment: NuInt09 poster proceedings, 4 page
Masses and magnetic moments of ground-state baryons in covariant baryon chiral perturbation theory
We report on some recent developments in our understanding of the light-quark
mass dependence and the SU(3) flavor symmetry breaking corrections to the
magnetic moments of the ground-state baryons in a covariant formulation of
baryon chiral perturbation theory, the so-called EOMS formulation. We show that
this covariant ChPT exhibits some promising features compared to its
heavy-baryon and infrared counterparts.Comment: 8 pages, 3 figures; plenary talk delivered by LSG at the 14th
national conference on nuclear structure, April 12nd - 16th, 2012, Huzhou,
Chin
Chiral perturbation theory study of the axial transition
We have performed a theoretical study of the axial Nucleon to Delta(1232)
() transition form factors up to one-loop order in covariant baryon
chiral perturbation theory within a formalism in which the unphysical spin-1/2
components of the fields are decoupled.Comment: 4 page
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