1,314 research outputs found
Measurement of the decay form factors in the OKA experiment
A precise measurement of the vector and axial-vector form factors difference
in the decay is presented.
About 95K events of are selected in
the OKA experiment. The result is .
Both errors are smaller than in the previous measurements.Comment: 9 pages, 8 figure
Stability study and time resolution measurement of Straw Tube detectors
Straw tube detectors are single wire proportional counters that are widely
used as a tracking device. We have carried out RD with a straw tube
detector prototype. The motivation of this work is to study the stability of
the performance in terms of gain and energy resolution of the straw tube
detectors under high rate radiation. Two different methods are incorporated to
perform this study. The gain and energy resolution of the detector are studied
along with its variation with ambient temperature and pressure. X-ray from a
radioactive source is used to irradiate the detector and the same source is
also used to monitor the energy spectra simultaneously for calculation of gain.
Variation of the gain and energy resolution of the straw tube detector under
X-ray irradiation in Ar/CO gas mixture is discussed in this article. We
have also estimated the time resolution of the straw tube detectors that can be
best achieved with cosmic rays as trigger for the same gas mixture. The details
of the measurement process and the experimental results are presented in this
article
Multi-layer scintillation detector for the MOON double beta decay experiment: Scintillation photon responses studied by a prototype detector MOON-1
An ensemble of multi-layer scintillators is discussed as an option of the
high-sensitivity detector Mo Observatory Of Neutrinos (MOON) for spectroscopic
measurements of neutrino-less double beta decays. A prototype detector MOON-1,
which consists of 6 layer plastic-scintillator plates, was built to study the
sensitivity of the MOON-type detector. The scintillation photon collection and
the energy resolution, which are key elements for the high-sensitivity
experiments, are found to be 1835+/-30 photo-electrons for 976 keV electrons
and sigma = 2.9+/-0.1% (dE/E = 6.8+/-0.3 % in FWHM) at the Qbb ~ 3 MeV region,
respectively. The multi-layer plastic-scintillator structure with good energy
resolution as well as good background suppression of beta-gamma rays is crucial
for the MOON-type detector to achieve the inverted hierarchy neutrino mass
sensitivity.Comment: 8 pages, 16 figures, submitted to Nucl.Instrum.Met
Searches for the light invisible axion-like particle in decay
A high statistics data sample of the decays is recorded by the OKA
collaboration. A missing mass analysis is performed to search for a light
invisible pseudoscalar axion-like particle (ALP) in the decay . No signal is observed, the upper limits for the branching
ratio of the decay are calculated. The confidence level upper limit is
changing from to for the ALP mass from 0 to
200 MeV/, except for the region of mass, where the upper limit
is .Comment: 6 pages, 6 figure
Observation of decay
The decay is observed by the OKA
collaboration. The branching ratio is measured to be . The branching ratio and energy spectrum are
consistent with ChPT prediction.Comment: arXiv admin note: text overlap with arXiv:2310.1642
Prospects for at CERN in NA62
The NA62 experiment will begin taking data in 2015. Its primary purpose is a
10% measurement of the branching ratio of the ultrarare kaon decay , using the decay in flight of kaons in an unseparated
beam with momentum 75 GeV/c.The detector and analysis technique are described
here.Comment: 8 pages for proceedings of 50 Years of CP
Constraints on New Physics in the Electron g-2 from a Search for Invisible Decays of a Scalar, Pseudoscalar, Vector, and Axial Vector
We performed a search for a new generic boson, which could be a scalar
(), pseudoscalar (), vector () or an axial vector () particle
produced in the 100 GeV electron scattering off nuclei, ,
followed by its invisible decay in the NA64 experiment at CERN. No evidence for
such process was found in the full NA64 data set of
electrons on target. We place new bounds on the coupling strengths
to electrons, and set constraints on their contributions to the electron
anomalous magnetic moment ,
for the mass region GeV. These results are an order of
magnitude more sensitive compared to the current accuracy on from the
electron experiments and recent high-precision determination of the fine
structure constant.Comment: 6 pages, 4 figure
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