4,696 research outputs found
Why does the recently proposed simple empirical formula for the lowest excitation energies work so well?
It has recently been shown that a simple empirical formula, in terms of the
mass number and the valence nucleon numbers, is able to describe the main
trends of the lowest excitation energies of the natural parity even multipole
states up to in even-even nuclei throughout the entire periodic table.
In an effort to understand why such a simple formula is so capable, we
investigate the possibility of associating each term of the empirical formula
with the specific part of the measured excitation energy graph.Comment: 9 pages, 3 figure
Spin-dependent empirical formula for the lowest excitation energies of the natural parity states in even-even nuclei
We present an empirical expression which holds for the lowest excitation
energy of the natural parity states in even-even nuclei throughout the entire
periodic table. This formula contains spin-dependent factors so that it is
applied to different multipole states with the same model parameters in
contrast to the recently proposed empirical expression where the model
parameters had to be fitted for each multipole separately.Comment: 9 pages, 5 figure
N_pN_n dependence of empirical formula for the lowest excitation energy of the 2^+ states in even-even nuclei
We examine the effects of the additional term of the type on the recently proposed empirical formula for the lowest excitation
energy of the states in even-even nuclei. This study is motivated by the
fact that this term carries the favorable dependence of the valence nucleon
numbers dictated by the scheme. We show explicitly that there is not
any improvement in reproducing by including the extra
term. However, our study also reveals that the excitation energies
, when calculated by the term alone (with the mass number
dependent term), are quite comparable to those calculated by the original
empirical formula.Comment: 14 pages, 5 figure
Reusable, polyethylene glycol-structured microfluidic channel for particle immunoassays
A microfluidic channel made entirely out of polyethylene glycol (PEG), not PEG coating to silicon or polydimethylsiloxane (PDMS) surface, was fabricated and tested for its reusability in particle immunoassays and passive protein fouling, at relatively high target concentrations (1 mg ml-1). The PEG devices were reusable up to ten times while the oxygen-plasma-treated polydimethyl siloxane (PDMS) device could be reused up to four times and plain PDMS were not reusable. Liquid was delivered spontaneously via capillary action and complicated bonding procedure was not necessary. The contact angle analysis revealed that the water contact angle on microchannel surface should be lower than ~60°, which are comparable to those on dried protein films, to be reusable for particle immunoassays and passive protein fouling
scheme and the valence proton-neutron interaction
We examine the common belief that the scheme is manifested as a
direct consequence of the valence proton-neutron interaction which has proven
to be a dominant factor in developing collectivity in nuclei. We show that the
simplification of the -plot of the lowest excitation energy is
introduced merely because the excitation energy always decreases when the
valence nucleon number becomes larger.Comment: 10 pages, 6 figure
Empirical formula applied to the lowest excitation energies of the natural parity odd multipole states in even-even nuclei
We applied our recently proposed empirical formula, a formula quite
successful in describing essential trends of the lowest excitation energies of
the natural parity even multipole states, to the lowest excitation energies of
the natural parity odd multipole states in even-even nuclei throughout the
entire periodic table. Even though the systematic behavior of the lowest
excitation energies of odd multipole states is quite different from those of
even multipole states, we have shown that the same empirical formula also holds
reasonably well for the odd multipole states with the exception of a few
certain instances.Comment: 23 pages, 11 figure
Momentum-kick model application to high multiplicity pp collisions at at the LHC
In this study, the momentum-kick model is used to understand the ridge
behaviours in dihadron -- correlations recently
reported by the LHC in high-multiplicity proton-proton (pp) collisions. The
kick stand model is based on a momentum kick by leading jets to partons in the
medium close to the leading jets. The medium where partons move freely is
assumed in the model regardless of collision systems. This helps us apply the
method to small systems like pp collisions in a simple way. Also, the momentum
transfer is purely kinematic and this provides us a strong way to approach the
ridge behaviour analytically. There are already several results with this
approach in high-energy heavy-ion collisions from the STAR and PHENIX at RHIC
and from the CMS at LHC. The momentum-kick model is extended to the recent
ridge results in high-multiplicity pp collisions with the ATLAS and CMS at LHC.
The medium property in high-multiplicity pp collisions is diagnosed with the
result of the model.Comment: 10 pages, 2 tables and 3 figure
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