4,870 research outputs found
A new insight into neutrino energy loss by electron capture of iron group nuclei in magnetars surface
Based on the relativistic mean-field effective interactions theory, and Lai
dong model \citep{b37, b38, b39}, we discuss the influences of superstrong
magnetic fields (SMFs) on electron Fermi energy, nuclear blinding energy, and
single-particle level structure in magnetars surface. By using the method of
Shell-Model Monte Carlo (SMMC), and the Random Phase Approximation (RPA)
theory, we detailed analyze the neutrino energy loss rates(NELRs) by electron
capture (EC) for iron group nuclei in SMFs.Comment: 22 pages, 8 figures, accepted for publication in ApJS. arXiv admin
note: text overlap with arXiv:astro-ph/0606674, arXiv:nucl-th/9707052,
arXiv:nucl-th/9801012, arXiv:1505.07304 by other author
Hidden symmetry and protection of Dirac points on the honeycomb lattice
The honeycomb lattice possesses a novel energy band structure, which is
characterized by two distinct Dirac points in the Brillouin zone, dominating
most of the physical properties of the honeycomb structure materials. However,
up till now, the origin of the Dirac points is unclear yet. Here, we discover a
hidden symmetry on the honeycomb lattice and prove that the existence of Dirac
points is exactly protected by such hidden symmetry. Furthermore, the moving
and merging of the Dirac points and a quantum phase transition, which have been
theoretically predicted and experimentally observed on the honeycomb lattice,
can also be perfectly explained by the parameter dependent evolution of the
hidden symmetry.Comment: 5 pages, 2 figures, +6 pages of supplementary information. Welcome
any comments
Weyl semimetals in optical lattices: moving and merging of Weyl points, and hidden symmetry at Weyl points
We propose to realize Weyl semimetals in a cubic optical lattice. We find
that there exist three distinct Weyl semimetal phases in the cubic optical
lattice for different parameter ranges. One of them has two pairs of Weyl
points and the other two have one pair of Weyl points in the Brillouin zone.
For a slab geometry with (010) surfaces, the Fermi arcs connecting the
projections of Weyl points with opposite topological charges on the surface
Brillouin zone is presented. By adjusting the parameters, the Weyl points can
move in the Brillouin zone. Interestingly, for two pairs of Weyl points, as one
pair of them meet and annihilate, the originial two Fermi arcs coneect into
one. As the remaining Weyl points annihilate further, the Fermi arc vanishes
and a gap is opened. Furthermore, we find that there always exists a hidden
symmetry at Weyl points, regardless of anywhere they located in the Brillouin
zone. The hidden symmetry has an antiunitary operator with its square being
.Comment: 10 pages, 5 figure
A New Kind of Deformed Hermite Polynomials and Its Applications
A new kind of deformed calculus was introduced recently in studying of
parabosonic coordinate representation. Based on this deformed calculus, a new
deformation of Hermite polynomials is proposed, its some properties such as
generating function, orthonormality, differential and integral representaions,
and recursion relations are also discussed in this paper. As its applications,
we calculate explicit forms of parabose squeezed number states, derive a
particularly simple subset of minimum uncertainty states for parabose
amplitude-squared squeezing, and discuss their basic squeezing behaviours.Comment: 18 pages, LaTe
Graded Lie Algebra Generating of Parastatistical Algebraic Structure
A new kind of graded Lie algebra (we call it graded Lie algebra) is
introduced as a framework for formulating parasupersymmetric theories. By
choosing suitable bose subspace of the graded Lie algebra and using
relevant generalized Jacobi identities, we generate the whole algebraic
structure of parastatistics.Comment: 8 pages, LaTe
Space Structure for the Simplest Parasupersymmetric System
Structure of the state-vector space for a system consisting of one mode
parabose and one mode parafermi degree of freedom with the same parastatistics
order is studied and a complete, orthonormal set of basis vectors in this
space is constructed. There is an intrinsic double degeneracy for state vectors
with parabosons and parafermions, where , , and
. It is also shown that the degeneracy plays a key role in
realization of exact supersymmetry for such a system
Topological semimetals with double-helix nodal link
Topological nodal line semimetals are characterized by the crossing of the
conduction and valence bands along one or more closed loops in the Brillouin
zone. Usually, these loops are either isolated or touch each other at some
highly symmetric points. Here, we introduce a new kind of nodal line semimetal,
that contains a pair of linked nodal loops. A concrete two-band model was
constructed, which supports a pair of nodal lines with a double-helix
structure, which can be further twisted into a Hopf link because of the
periodicity of the Brillouin zone. The nodal lines are stabilized by the
combined spatial inversion and time reversal
symmetry; the individual and symmetries must be
broken. The band exhibits nontrivial topology that each nodal loop carries a
Berry flux. Surface flat bands emerge at the open boundary and are
exactly encircled by the projection of the nodal lines on the surface Brillouin
zone. The experimental implementation of our model using cold atoms in optical
lattices is discussed.Comment: 10 pages, 7 figures. The title is changed, the main text and
Supplemental Material are update
Deformed Legendre Polynomial and Its Application
A new kind of deformed calculus was introduced recently in studying of
parabosonic coordinate representation. Based on this deformed calculus, a new
deformation of Legendre polynomials is proposed in this paper, some properties
and applications of which are also discussed.Comment: 11 pages, LaTe
Study of Magnetic Hysteresis Effects in a Storage Ring Using Precision Tune Measurement
With advances in accelerator science and technology in the recent decades,
the accelerator community has focused on the development of next-generation
light sources, for example the diffraction-limited storage rings (DLSRs), which
requires precision control of the electron beam energy and betatron tunes. This
work is aimed at understanding magnet hysteresis effects on the electron beam
energy and lattice focusing in the circular accelerators, and developing new
methods to gain better control of these effects. In this paper, we will report
our recent experimental study of the magnetic hysteresis effects and their
impacts on the Duke storage ring lattice using the transverse feedback based
precision tune measurement system. The major magnet hysteresis effects
associated with magnet normalization and lattice ramping are carefully studied
to determine an effective procedure for lattice preparation while maintaining a
high degree of reproducibility of lattice focusing. The local hysteresis
effects are also studied by measuring the betatron tune shifts resulted from
adjusting the setting of a quadrupole. A new technique has been developed to
precisely recover the focusing strength of the quadrupole by returning it to a
proper setting to overcome the local hysteresis effect
Connecting neutron star observations to the high density equation of state of quasi-particle model
The observation of solar-mass neutron-like star gives
constraint on the equation of state (EOS) of cold, condensed matter. In this
paper, the EOS for both pure quark star and hybrid star with a quark core
described by quasi-particle model are considered. The parameters of
quasi-particle model which affect the mass of both quark star and hybrid star
can be constrained by the observation.Comment: 7 pages, 11 figure
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