21 research outputs found
First measurement of the muon neutrino charged current quasielastic double differential cross section
A high-statistics sample of charged-current muon neutrino scattering events collected with the MiniBooNE experiment is analyzed to extract the first measurement of the double differential cross section (d(2)sigma/dT(mu)dcos theta(mu)) for charged-current quasielastic (CCQE) scattering on carbon. This result features minimal model dependence and provides the most complete information on this process to date. With the assumption of CCQE scattering, the absolute cross section as a function of neutrino energy (sigma[E-nu]) and the single differential cross section (d sigma/dQ(2)) are extracted to facilitate comparison with previous measurements. These quantities may be used to characterize an effective axial-vector form factor of the nucleon and to improve the modeling of low-energy neutrino interactions on nuclear targets. The results are relevant for experiments searching for neutrino oscillations.This work was conducted with support from Fermilab,
the U.S. Department of Energy, and the National Science
Foundation.Peer reviewe
Search for core-collapse supernovae using the MiniBooNE neutrino detector
We present a search for core-collapse supernovae in the Milky Way galaxy, using the MiniBooNE neutrino detector. No evidence is found for core-collapse supernovae occurring in our Galaxy in the period from December 14, 2004 to July 31, 2008, corresponding to 98% live time for collection. We set a limit on the core-collapse supernova rate out to a distance of 13.4 kpc to be less than 0.69 supernovae per year at 90% C. L.We acknowledge the support of Fermilab, the Department of Energy, and the National Science Foundation. We are grateful to John Beacom for his valuable insight and advice. We thank Alessandro Mirizzi, Georg G. Raffelt, and Pasquale D. Serpico for providing the probability distribution for the Milky Way.Peer reviewe
Constraints on non-thermal Dark Matter from Planck lensing extraction
Distortions of CMB temperature and polarization anisotropy maps caused by
gravitational lensing, observable with high angular resolution and sensitivity,
can be used to constrain the sterile neutrino mass, offering several advantages
against the analysis based on the combination of CMB, LSS and Ly\alpha forest
power spectra. As the gravitational lensing effect depends on the matter
distribution, no assumption on light-to-mass bias is required. In addition,
unlike the galaxy clustering and Ly\alpha forest power spectra, the projected
gravitational potential power spectrum probes a larger range of angular scales,
the non-linear corrections being required only at very small scales. Taking
into account the changes in the time-temperature relation of the primordial
plasma and the modification of the neutrino thermal potential, we compute the
projected gravitational potential power spectrum and its correlation with the
temperature in the presence of DM sterile neutrino. We show that the
cosmological parameters are generally not biased when DM sterile neutrino is
included. From this analysis we found a lower limit on DM sterile neutrino mass
m_s >2.08 keV at 95% CL, consistent with the lower mass limit obtained from the
combined analysis of CMB, SDSS 3D power spectrum and SDSS Ly\alpha forest power
spectrum ( keV). We conclude that although the information that
can be obtained from lensing extraction is rather limited due to the high level
of the lensing noise of Planck experiment, weak lensing of CMB offers a
valuable alternative to constrain the dark matter sterile neutrino mass.Comment: 15 pages, 6 figure
Nuclear Physics with Electroweak Probes
In recent years, the italian theoretical Nuclear Physics community has played
a leading role in the development of a unified approach, allowing for a
consistent and fully quantitative description of the nuclear response to
electromagnetic and weak probes. In this paper I review the main achievements
in both fields, point out some of the open problems, and outline the most
promising prospects.Comment: Invited Talk at the XII Workshop on Theoretical Nuclear Physics in
Italy, Cortona, October 8-10, 200
Recoilless resonant neutrino capture and basics of neutrino oscillations
It is shown that the experiment on recoilless resonant emission and
absorption of , proposed recently by Raghavan, could have an
important impact on our understanding of the physics of neutrino oscillations.Comment: Additional information in the last chapte
Status and perspectives of short baseline studies
The study of flavor changing neutrinos is a very active field of research. I
will discuss the status of ongoing and near term experiments investigating
neutrino properties at short distances from the source. In the next few years,
the Double Chooz, RENO and Daya Bay reactor neutrino experiments will start
looking for signatures of a non-zero value of the mixing angle
with much improved sensitivities. The MiniBooNE experiment is investigating the
LSND anomaly by looking at both the and
appearance channels. Recent results on
cross section measurements will be discussed briefly.Comment: 6 pages, 2 figures, to appear in the proceedings of the 11th
International Conference on Topics in Astroparticle and Underground Physics
(TAUP 2009), Rome, Italy, 1-5 July 200
First Measurement of Monoenergetic Muon Neutrino Charged Current Interactions
We report the first measurement of monoenergetic muon neutrino charged
current interactions. MiniBooNE has isolated 236 MeV muon neutrino events
originating from charged kaon decay at rest ()
at the NuMI beamline absorber. These signal -carbon events are
distinguished from primarily pion decay in flight and
backgrounds produced at the target station and decay pipe
using their arrival time and reconstructed muon energy. The significance of the
signal observation is at the 3.9 level. The muon kinetic energy,
neutrino-nucleus energy transfer (), and total cross
section for these events is extracted. This result is the first known-energy,
weak-interaction-only probe of the nucleus to yield a measurement of
using neutrinos, a quantity thus far only accessible through electron
scattering.Comment: 6 pages, 4 figure
WMAP 5-year constraints on lepton asymmetry and radiation energy density: Implications for Planck
In this paper we set bounds on the radiation content of the Universe and
neutrino properties by using the WMAP-5 year CMB measurements complemented with
most of the existing CMB and LSS data (WMAP5+All),imposing also self-consistent
BBN constraints on the primordial helium abundance. We consider lepton
asymmetric cosmological models parametrized by the neutrino degeneracy
parameter and the variation of the relativistic degrees of freedom, due to
possible other physical processes occurred between BBN and structure formation
epochs. We find that WMAP5+All data provides strong bounds on helium mass
fraction and neutrino degeneracy parameter that rivals the similar bounds
obtained from the conservative analysis of the present data on helium
abundance. We also find a strong correlation between the matter energy density
and the redshift of matter-radiation equality, z_re, showing that we observe
non-zero equivalent number of relativistic neutrinos mainly via the change of
the of z_re, rather than via neutrino anisotropic stress claimed by the WMAP
team. We forecast that the CMB temperature and polarization measurements
observed with high angular resolutions and sensitivities by the future Planck
satellite will reduce the errors on these parameters down to values fully
consistent with the BBN bounds
Majorana Neutrino Mixing
The most plausible see-saw explanation of the smallness of the neutrino
masses is based on the assumption that total lepton number is violated at a
large scale and neutrinos with definite masses are Majorana particles. In this
review we consider in details difference between Dirac and Majorana neutrino
mixing and possibilities of revealing Majorana nature of neutrinos with
definite masses
A Search for Electron Antineutrino Appearance at the 1 Scale
The MiniBooNE Collaboration reports initial results from a search for
oscillations. A signal-blind analysis was
performed using a data sample corresponding to protons on
target. The data are consistent with background prediction across the full
range of neutrino energy reconstructed assuming quasielastic scattering, MeV: 144 electron-like events have been observed in this
energy range, compared to an expectation of events. No
significant excess of events has been observed, both at low energy, 200-475
MeV, and at high energy, 475-1250 MeV. The data are inconclusive with respect
to antineutrino oscillations suggested by data from the Liquid Scintillator
Neutrino Detector at Los Alamos National Laboratory.Comment: 5 pages, 3 figures, 2 table