6,630 research outputs found
Constraining nuclear physics parameters with current and future COHERENT data
Motivated by the recent observation of coherent elastic neutrino-nucleus
scattering (CENS) at the COHERENT experiment, our goal is to explore its
potential in probing important nuclear structure parameters. We show that the
recent COHERENT data offers unique opportunities to investigate the neutron
nuclear form factor. Our present calculations are based on the deformed Shell
Model (DSM) method which leads to a better fit of the recent CENS data,
as compared to known phenomenological form factors such as the Helm-type,
symmetrized Fermi and Klein-Nystrand. The attainable sensitivities and the
prospects of improvement during the next phase of the COHERENT experiment are
also considered and analyzed in the framework of two upgrade scenarios.Comment: 13 pages, 5 figures, 2 tables; v2: minor corrections, version to
appear in PL
Efficient low-threshold lasers based on an erbium-doped holey fiber
We report experimental results on the continuous-wave lasers based on a small core erbium-doped holey fiber. In a simple Fabry-Perot-type cavity with high output coupling, we demonstrate low-threshold (0.55 mW) high slope-efficiency (57.3%) operation confirming both the quality and exceptionally high gain efficiency of the fiber. In an all-fiber ring cavity where the cavity loss is reduced, we show that it is possible to achieve a low-threshold laser with extremely wide tunability (>100 nm around 1550 nm). Our results illustrate some of the unique opportunities provided by active small core holey fibers
Characterizations of GEM detector prototype
At NISER-IoP detector laboratory an initiative is taken to build and test Gas
Electron Multiplier (GEM) detectors for ALICE experiment. The optimisation of
the gas flow rate and the long-term stability test of the GEM detector are
performed. The method and test results are presented.Comment: 3 Pages, 4 figure
The pressure-amorphized state in zirconium tungstate: a precursor to decomposition
In contrast to widely accepted view that pressure-induced amorphization arises due to kinetic hindrance of equilibrium phase transitions, here we provide evidence that the metastable pressure-amorphized state in zirconium tungstate is a precursor to decomposition of the compound into a mixture of simple oxides. This is from the volume collapse ΔV across amorphization, which is obtained for the first time by measuring linear dimensions of irreversibly amorphized samples during their recovery to the original cubic phase upon isochronal annealing up to 1000 K. The anomalously large ΔV of 25.7 ± 1.2% being the same as that expected for the decomposition indicates that this amorphous state is probably a precursor to kinetically hindered decomposition. A P–T diagram of the compound is also proposed
Long-term stability test of a triple GEM detector
The main aim of the study is to perform the long-term stability test of gain
of the single mask triple GEM detector. A simple method is used for this long-
term stability test using a radioactive X-ray source with high activity. The
test is continued till accumulation of charge per unit area > 12.0 mC/mm2. The
details of the chamber fabrication, the test set-up, the method of measurement
and the test results are presented in this paper.Comment: 8 pages, 5 figure
Leptogenesis and low energy CP phases with two heavy neutrinos
An attractive explanation for non-zero neutrino masses and small matter
antimatter asymmetry of the present Universe lies in "leptogenesis". At present
the {\it size} of the lepton asymmetry is precisely known, while the {\it sign}
is not known yet. In this work we determine the sign of this asymmetry in the
framework of two right handed neutrino models by relating the leptogenesis
phase(s) with the low energy CP violating phases appearing in the leptonic
mixing matrix. It is shown that the knowledge of low energy lepton number
violating re-phasing invariants can indeed determine the sign of the present
matter antimatter asymmetry of the Universe and hence indirectly probing the
light physical neutrinos to be Majorana type.Comment: 26 pages (revtex), 8 eps figures, Typos corrected and one reference
is added, Section VI is expanded, Two new figures are added, Journal version,
To appear in PR
- …