135 research outputs found
Study of the derivative expansions for the nuclear structure functions
We study the convergence of the series expansions sometimes used in the
analysis of the nuclear effects in Deep Inelastic Scattering (DIS) proccesses
induced by leptons. The recent advances in statistics and quality of the data,
in particular for neutrinos calls for a good control of the theoretical
uncertainties of the models used in the analysis. Using realistic nuclear
spectral functions which include nucleon correlations, we find that the
convergence of the derivative expansions to the full results is poor except at
very low values of
Two Particle-Hole Excitations in Charged Current Quasielastic Antineutrino--Nucleus Scattering
We evaluate the quasielastic and multinucleon contributions to the
antineutrino nucleus scattering cross section and compare our results with the
recent MiniBooNE data. We use a local Fermi gas model that includes RPA
correlations and gets the multinucleon part from a systematic many body
expansion of the boson selfenergy in the nuclear medium. The same model had
been quite successful for the neutrino cross section and contains no new
parameters. We have also analysed the relevance of 2p2h events for the
antineutrino energy reconstruction.Comment: 6 pages, 4 figure
Neutrino Energy Reconstruction and the Shape of the CCQE-like Total Cross Section
We show that because of the multinucleon mechanism effects, the algorithm
used to reconstruct the neutrino energy is not adequate when dealing with
quasielastic-like events, and a distortion of the total flux unfolded cross
section shape is produced. This amounts to a redistribution of strength from
high to low energies, which gives rise to a sizable excess (deficit) of low
(high) energy neutrinos. This distortion of the shape leads to a good
description of the MiniBooNE unfolded CCQE-like cross sections published in
Phys.Rev. D81 (2010) 092005. However, these changes in the shape are artifacts
of the unfolding process that ignores multinucleon mechanisms.Comment: 11 pages, 6 figures. Some references and comments adde
Weak Kaon Production off the Nucleon
The weak kaon production off the nucleon induced by neutrinos is studied at
the low and intermediate energies of interest for some ongoing and future
neutrino oscillation experiments. This process is also potentially important
for the analysis of proton decay experiments. We develop a microscopical model
based on the SU(3) chiral Lagrangians. The basic parameters of the model are
fpi, the pion decay constant, Cabibbo's angle, the proton and neutron magnetic
moments and the axial vector coupling constants for the baryons octet, D and F,
that are obtained from the analysis of the semileptonic decays of neutron and
hyperons. The studied mechanisms are the main source of kaon production for
neutrino energies up to 1.2 to 1.5 GeV for the various channels and the cross
sections are large enough to be amenable to be measured by experiments such as
Minerva and T2K
Weak Production of Strange Particles and Mesons off the Nucleon
The strange particle production induced by (anti)neutrino off nucleon has
been studied for and channels.
The reactions those we have considered are for the production of single
kaon/antikaon, eta and associated particle production processes.
We have developed a microscopical model based on the SU(3) chiral Lagrangian.
The basic parameters of the model are , the pion decay constant, Cabibbo
angle, the proton and neutron magnetic moments and the axial vector coupling
constants for the baryons octet. For antikaon production we have also included
(1385) resonance and for eta production (1535) and
(1650) resonances are included.Comment: To appear in AIP Conf. Proc. of the Workshop CETUP*14, 12 Pages, 13
Figure
Antineutrino induced antikaon production off the nucleon
The charged current antikaon production off nucleons induced by antineutrinos
is studied at low and intermediate energies. We extend here our previous
calculation on kaon production induced by neutrinos. We have developed a
microscopic model that starts from the SU(3) chiral Lagrangians and includes
background terms and the resonant mechanisms associated to the lowest lying
resonance in the channel, namely, the Sigma*(1385). Our results could be of
interest for the background estimation of various neutrino oscillation
experiments like MiniBooNE and SuperK. They can also be helpful for the planned
antineutrino experiments like MINERvA, NOvA and T2K phase II and for beta-beam
experiments with antineutrino energies around 1 GeV.Comment: 15 pages and 6 figures. This version matches accepted version for
publication in Physical Review
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