1,054 research outputs found
Systematic investigation of the rotational bands in nuclei with using a particle-number conserving method based on a cranked shell model
The rotational bands in nuclei with are investigated
systematically by using a cranked shell model (CSM) with the pairing
correlations treated by a particle-number conserving (PNC) method, in which the
blocking effects are taken into account exactly. By fitting the experimental
single-particle spectra in these nuclei, a new set of Nilsson parameters
( and ) and deformation parameters ( and
) are proposed. The experimental kinematic moments of inertia
for the rotational bands in even-even, odd- and odd-odd nuclei, and the
bandhead energies of the 1-quasiparticle bands in odd- nuclei, are
reproduced quite well by the PNC-CSM calculations. By analyzing the
-dependence of the occupation probability of each cranked Nilsson
orbital near the Fermi surface and the contributions of valence orbitals in
each major shell to the angular momentum alignment, the upbending mechanism in
this region is understood clearly.Comment: 21 pages, 24 figures, extended version of arXiv: 1101.3607 (Phys.
Rev. C83, 011304R); added refs.; added Fig. 4 and discussions; Phys. Rev. C,
in pres
Regularization dependence of pion generalised parton distributions
Pion generalised parton distributions are calculated within the framework of
the Nambu--Jona-Lasinio model using different regularization schemes, including
the proper time regularization scheme, the three dimensional momentum cutoff
scheme, the four dimensional momentum cutoff scheme, and the Pauli-Villars
regularization scheme. Furthermore, we check the theoretical constraints of
pion generalised parton distributions required by the symmetries of quantum
chromodynamics in different regularization schemes. The diagrams of pion parton
distribution functions are plotted, in addition, we evaluate the Mellin moments
of generalised parton distributions, which related to the electromagnetic and
gravitational form factors of pion. Pion generalised parton distributions are
continuous but not differential at , when considering the effect
of D-term, generalised parton distributions become not continuous at in all the four regularization schemes. Generalised parton distributions
in impact parameter space are considered, the width distribution of quark
in the pion and the mean-squared
are calculated. The light-front transverse-spin distributions are studied, when
quark polarized in the light-front-transverse direction, the
transverse-spin density is no longer symmetric around , the
peaks shift to , we compare the average transverse shift
and in
different regularization schemes. The light-cone energy radius and
the light-cone charge radius are also evaluated, we find that in the
proper time regularization scheme the values of these quantities are the
largest, in the three dimensional momentum cutoff scheme they are the smallest.Comment: 34 pages, 39 figure
Nuclear superfluidity for antimagnetic rotation in Cd and Cd
The effect of nuclear superfluidity on antimagnetic rotation bands in
Cd and Cd are investigated by the cranked shell model with the
pairing correlations and the blocking effects treated by a particle-number
conserving method. The experimental moments of inertia and the reduced
transition values are excellently reproduced. The nuclear superfluidity is
essential to reproduce the experimental moments of inertia. The two-shears-like
mechanism for the antimagnetic rotation is investigated by examining the shears
angle, i.e., the closing of the two proton hole angular momenta, and its
sensitive dependence on the nuclear superfluidity is revealed.Comment: 14 pages, 4 figure
μ-Adipato-bis[chlorido(2,2′:6′,2′′-terpyridine)copper(II)] tetrahydrate
In the title compound, [Cu2(C6H8O4)Cl2(C15H11N3)2]·4H2O, the dinuclear copper complex is located on a crystallographic inversion centre. Each Cu atom is in a distorted square-pyramidal coordination environment, with one O atom of an adipate dianion and three N atoms from the 2,2′:6′,2′′-terpyridine ligand occupying the basal plane, and one chlorine in the apical site. In addition, there is weak Cu—O interaction opposite of the chlorine with a distance of 2.768 (1) Å. The adipate ligand adopts a gauche–anti–gauche conformation. The interstitial water molecules form hydrogen-bonded tertramers that are connected to the complexes via O—H⋯O and O—H⋯Cl hydrogen bonds, thus leading to the formation of tightly hydrogen-bonded layers extending perpendicular to the b-axis direction
Measurement-device-independent QKD with Modified Coherent State
The measurement-device-independent quantum key distribution (MDI-QKD)
protocol has been proposed for the purpose of removing the detector side
channel attacks. Due to the multi-photon events of coherent states sources,
real-life implementations of MDI-QKD protocol must employ decoy states to beat
the photon-number-splitting attack. Decoy states for MDI-QKD based on the weak
coherent states have been studied recently. In this paper, we propose to
perform MDI-QKD protocol with modified coherent states (MCS) sources. We
simulate the performance of MDI-QKD with the decoy states based on MCS sources.
And our simulation indicates that both the secure-key rate and transmission
distance can be improved evidently with MCS sources.The physics behind this
improvement is that the probability of multi-photon events of the MCS is lower
than that of weak coherent states while at the same time the probability of
single-photon is higher
Rotational properties of the superheavy nucleus 256Rf and its neighboring even-even nuclei in particle-number conserving cranked shell model
The ground state band was recently observed in the superheavy nucleus 256Rf.
We study the rotational properties of 256Rf and its neighboring even-even
nuclei by using a cranked shell model (CSM) with the pairing correlations
treated by a particle-number conserving (PNC) method in which the blocking
effects are taken into account exactly. The kinematic and dynamic moments of
inertia of the ground state bands in these nuclei are well reproduced by the
theory. The spin of the lowest observed state in 256Rf is determined by
comparing the experimental kinematic moments of inertia with the PNC-CSM
calculations and agrees with previous spin assignment. The effects of the high
order deformation varepsilon6 on the angular momentum alignments and dynamic
moments of inertia in these nuclei are discussed.Comment: 7 pages, 6 figures; References and discussion about the cranking
Nilsson model added, Fig. 3 modified and Figs. 5 and 6 added; Phys. Rev. C,
in pres
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