1,633 research outputs found
Uncertainties in nuclear transition matrix elements for neutrinoless decay II: the heavy Majorana neutrino mass mechanism
Employing four different parametrization of the pairing plus multipolar type
of effective two-body interaction and three different parametrizations of
Jastrow-type of short range correlations, the uncertainties in the nuclear
transition matrix elements due to the exchange of heavy
Majorana neutrino for the transition of neutrinoless
double beta decay of Zr, Zr, Mo, Mo, Ru,
Pd, Te and Nd isotopes in the PHFB model are
estimated to be around 25%. Excluding the nuclear transition matrix elements
calculated with Miller-Spenser parametrization of Jastrow short range
correlations, the uncertainties are found to be 10%-15% smaller
Lichen flora of Surinsar-Mansar wildlife sanctuary, J&K
The present study conducted to enumerate the lichens from the so far unexplored Surinsar-Mansar wildlife sanctuary, J&K, revealed the presence of 30 species belonging to 18 genera from 14 families. The species belonged to different growth forms (21 crustose, 8 foliose and 1 fruticose) and are also growing on various substrata (corticolous-17 and saxicolous-13). Mangifera indica hosted the maximum number (12) while Pinus roxburghii did not host any lichen species in this area
Constraining Form Factors with the Method of Unitarity Bounds
The availability of a reliable bound on an integral involving the square of
the modulus of a form factor on the unitarity cut allows one to constrain the
form factor at points inside the analyticity domain and its shape parameters,
and also to isolate domains on the real axis and in the complex energy plane
where zeros are excluded. In this lecture note, we review the mathematical
techniques of this formalism in its standard form, known as the method of
unitarity bounds, and recent developments which allow us to include information
on the phase and modulus along a part of the unitarity cut. We also provide a
brief summary of some results that we have obtained in the recent past, which
demonstrate the usefulness of the method for precision predictions on the form
factors.Comment: 12 pages, 2 figures; Lecture given at the DAE-BRNS Workshop on Hadron
Physics, Bhabha Atomic Research Centre, Mumbai, India, October 31-November 4,
2011, submitted to Proceeding
Preliminary study of feasibility of an experiment looking for excited state double beta transitions in tin
An attempt to study the feasibility of a new experiment to search for double
beta decay in Sn and Sn was carried out by using ultra-low
background HPGe detector (244 cm) inside the Gran Sasso National
Laboratory (LNGS) of the INFN (Italy). A small sample of natural Sn was
examined for 2367.5 h. The radioactive contamination of the sample has been
estimated. The data has also been considered to calculate the present
sensitivity for the proposed search; half-life limits years for EC and EC-EC processes in Sn and
years for transition in Sn were
measured. In the last section of the paper the enhancement of the sensitivity
for a proposed experiment with larger mass to reach theoretically estimated
values of half-lives is discussed.Comment: 20 pages, 11 figures, 4 tables, accepted for publication in NIMA (in
press
Nuclear deformation and neutrinoless double- decay of Zr, Mo, Ru, Pd, Te and Nd nuclei in mass mechanism
The decay of Zr, Mo,
Ru, Pd, Te and Nd isotopes for the
transition is studied in the Projected Hartree-Fock-Bogoliubov
framework. In our earlier work, the reliability of HFB intrinsic wave functions
participating in the decay of the above mentioned nuclei
has been established by obtaining an overall agreement between the
theoretically calculated spectroscopic properties, namely yrast spectra,
reduced : transition probabilities, quadrupole moments
, gyromagnetic factors as well as half-lives
for the transition and the available
experimental data. In the present work, we study the decay for the transition in the mass mechanism
and extract limits on effective mass of light as well as heavy neutrinos from
the observed half-lives using nuclear
transition matrix elements calculated with the same set of wave functions.
Further, the effect of deformation on the nuclear transition matrix elements
required to study the decay in the mass
mechanism is investigated. It is noticed that the deformation effect on nuclear
transition matrix elements is of approximately same magnitude in and decay.Comment: 15 pages, 1 figur
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