106 research outputs found
Revisiting the 'LSND anomaly' II: critique of the data analysis
This paper, together with a preceding paper, questions the so-called 'LSND
anomaly': a 3.8 sigma excess of antielectronneutrino interactions over standard
backgrounds, observed by the LSND Collaboration in a beam dump experiment with
800 MeV protons. That excess has been interpreted as evidence for the
antimuonneutrino to antielectronneutrino oscillation in the \Deltam2 range from
0.2 eV2 to 2 eV2. Such a \Deltam2 range is incompatible with the widely
accepted model of oscillations between three light neutrino species and would
require the existence of at least one light 'sterile' neutrino. In a preceding
paper, it was concluded that the estimates of standard backgrounds must be
significantly increased. In this paper, the LSND Collaboration's estimate of
the number of antielectronneutrino interactions followed by neutron capture,
and of its error, is questioned. The overall conclusion is that the
significance of the 'LSND anomaly' is not larger than 2.3 sigma.Comment: 30 pages, 16 figures, 6 table
Why the paper CERN-PH-EP-2009-015 (arXiv:0903.4762) is scientifically unacceptable
The paper CERN-PH-EP-2009-015 (arXiv:0903.4762) by A. Bagulya et al. violates
standards of quality of work and scientific ethics on several counts. The paper
contains assertions that contradict established detector physics. The paper
falls short of proving the correctness of the authors' concepts and results.
The paper ignores or quotes misleadingly pertinent published work. The paper
ignores the fact that the authors' concepts and results have already been shown
wrong in the published literature. The authors seem unaware that cross-section
results from the 'HARP Collaboration' that are based on the paper's concepts
and algorithms are in gross disagreement with the results of a second analysis
of the same data, and with the results of other experiments.Comment: 8 pages, 3 figure
Cross-sections of large-angle hadron production in proton- and pion-nucleus interactions VII: tin nuclei and beam momenta from \pm3 GeV/c to \pm15 GeV/c
We report on double-differential inclusive cross-sections of the production
of secondary protons, charged pions, and deuterons, in the interactions with a
5% nuclear interaction length thick stationary tin target, of proton and pion
beams with momentum from \pm3 GeV/c to \pm15 GeV/c. Results are given for
secondary particles with production angles between 20 and 125 degrees.
Cross-sections on tin nuclei are compared with cross-sections on beryllium,
carbon, copper, tantalum and lead nuclei.Comment: 68 pages, 13 figure
Comparison of Geant4 hadron generation with data from the interactions with beryllium nuclei of +8.9 GeV/c protons and pions, and of -8 GeV/c pions
Hadron generation in the Geant4 simulation tool kit is compared with
inclusive spectra of secondary protons and pions from the interactions with
beryllium nuclei of +8.9 GeV/c protons and pions, and of -8.0 GeV/c pions. The
data were taken in 2002 at the CERN Proton Synchrotron with the HARP
spectrometer. We report on significant disagreements between data and simulated
data especially in the polar-angle distributions of secondary protons and
pions.Comment: 15 pages, 13 figure
Cross-Sections of Large-Angle Hadron Production in Proton- and Pion-Nucleus Interactions V: Lead Nuclei and Beam Momenta from +/-3 Gev/c to +/-15 Gev/c
We report on double-differential inclusive cross-sections of the production
of secondary protons, charged pions, and deuterons, in the interactions with a
5% nuclear interaction length thick stationary lead target, of proton and pion
beams with momentum from +/-3 GeV/c to +/-15 GeV/c. Results are given for
secondary particles with production angles 20 to 125 degrees. Cross-sections on
lead nuclei are compared with cross-sections on beryllium, copper, and tantalum
nuclei.Comment: 67 pages, 13 figures, 47 table
Comments on TPC and RPC calibrations reported by the HARP Collaboration
The HARP Collaboration recently published calibrations of their TPC and RPC
detectors, and differential cross-sections of large-angle pion production in
proton-nucleus collisions. We argue that these calibrations are biased and
cross-sections based on them should not be trusted.Comment: 17 pages, 13 figure
Cross-sections of large-angle hadron production in proton- and pion-nucleus interactions VI: carbon nuclei and beam momenta from \pm 3 GeV/c to \pm 15 GeV/c
We report on double-differential inclusive cross-sections of the production
of secondary protons, charged pions, and deuterons, in the interactions with a
5% nuclear interaction length thick stationary carbon target, of proton and
pion beams with momentum from \pm 3 GeV/c to \pm 15 GeV/c. Results are given
for secondary particles with production angles between 20 and 125 degrees.
Cross-sections on carbon nuclei are compared with cross-sections on beryllium,
copper, tantalum and lead nuclei.Comment: 67 pages, 13 figure
Cross-Sections of Large-Angle Hadron Production in Proton- and Pion-Nucleus Interactions III: Tantalum Nuclei and Beam Momenta from +/-3 Gev/c to +/-15 Gev/c
We report on double-differential inclusive cross-sections of the production
of secondary protons, charged pions, and deuterons, in the interactions with a
5% nuclear interaction length thick stationary tantalum target, of proton and
pion beams with momentum from +/-3 GeV/c to +/-15 GeV/c. Results are given for
secondary particles with production angles between 20 and 125 degrees. They are
of particular relevance for the optimization of the design parameters of the
proton driver of a neutrino factory.Comment: 68 pages, 12 figures, corrections in v2: added 'HARP -CDP group' to
author name, corrected two typos in Table 4 (last two p values for 65-90
degrees were all 0.972
Measurement of the production cross-section of positive pions in the collision of 8.9 GeV/c protons on beryllium
The double-differential production cross-section of positive pions,
, measured in the HARP experiment is presented.
The incident particles are 8.9 GeV/c protons directed onto a beryllium target
with a nominal thickness of 5% of a nuclear interaction length. The measured
cross-section has a direct impact on the prediction of neutrino fluxes for the
MiniBooNE and SciBooNE experiments at Fermilab. After cuts, 13 million protons
on target produced about 96,000 reconstructed secondary tracks which were used
in this analysis. Cross-section results are presented in the kinematic range
0.75 GeV/c < < 6.5 GeV/c and 30 mrad < < 210 mrad in
the laboratory frame.Comment: 39 pages, 21 figures. Version accepted for publication by Eur. Phys.
J.
First Measurement of the Transverse Spin Asymmetries of the Deuteron in Semi-Inclusive Deep Inelastic Scattering
First measurements of the Collins and Sivers asymmetries of charged hadrons
produced in deep-inelastic scattering of muons on a transversely polarized
6-LiD target are presented. The data were taken in 2002 with the COMPASS
spectrometer using the muon beam of the CERN SPS at 160 GeV/c. The Collins
asymmetry turns out to be compatible with zero, as does the measured Sivers
asymmetry within the present statistical errors.Comment: 6 pages, 2 figure
- …