5,040 research outputs found
Triaxiality in 48Cr
Rotational behavior inducing triaxiality is discussed for 48Cr in the cranked
Nilsson-Strutinsky (CNS) model, as well as in the spherical shell model. It is
shown that the low-spin region up to about I=8, has a prolate well-deformed
shape. At higher spins the shape is triaxial with a "negative-gamma"
deformation, that is, with rotation around the classically forbidden
intermediate axis. By comparing calculated B(E2)-values and spectroscopic
quadrupole moments in the CNS with spherical shell model results and
experimental data, the triaxial rotation around the intermediate axis is
confirmed.Comment: 9 pages, including 6 figures; submitted to Physics Letters
Parametrizing the Neutrino sector
The original Standard Model has massless neutrinos, but the observation of
neutrino oscillations requires that neutrinos are massive. The simple extension
of adding gauge singlet fermions to the particle spectrum allows normal Yukawa
mass terms for neutrinos. The seesaw mechanism then suggests an explanation for
the observed smallness of the neutrino masses. After reviewing the framework of
the seesaw we suggest a parametrization that directly exhibits the smallness of
the mass ratios in the seesaw for an arbitrary number of singlet fermions and
we present our plans to perform calculations for a process that might be
studied at the LHC.Comment: 8 pages; uses appolb.cls; submitted to the proceedings of "Matter to
the Deepest: Recent Development in Physics of Fundamental Interactions",
Ustron, Poland, 12-18 Sep 201
Gamow-Teller GT+ distributions in nuclei with mass A=90-97
We investigate the Gamow-Teller strength distributions in the
electron-capture direction in nuclei having mass A=90-97, assuming a 88Sr core
and using a realistic interaction that reasonably reproduces nuclear
spectroscopy for a wide range of nuclei in the region as well as experimental
data on Gamow-Teller strength distributions. We discuss the systematics of the
distributions and their centroids. We also predict the strength distributions
for several nuclei involving stable isotopes that should be experimentally
accessible for one-particle exchange reactions in the near future.Comment: 9 pages, 10 figures (from 17 eps files), to be submitted to
Phys.Rev.C; corrected typos, minor language change
The Cranked Nilsson-Strutinsky versus the Spherical Shell Model: A Comparative Study of pf-Shell Nuclei
A comparative study is performed of a deformed mean field theory, represented
by the cranked Nilsson-Strutinsky (CNS) model, and the spherical shell model.
Energy spectra, occupation numbers, B(E2)-values, and spectroscopic quadrupole
moments in the light pf shell nuclei are calculated in the two models and
compared. The result is also compared to available experimental data which are
generally well described by the shell model. Although the Nilsson-Strutinsky
calculation does not include pairing, both the subshell occupation numbers and
quadrupole properties are found to be rather similar in the two models. It is
also shown that ``unpaired'' shell model calculations produce very similar
energies as the CNS at all spins. The role of the pairing energy in the
description of backbending and signature splitting in odd-mass nuclei is also
discussed.Comment: 14 pages, 20 figures, submitted to Phys.Rev.
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