2,597 research outputs found
Uniform W^{1,p} Estimates for Systems of Linear Elasticity in a Periodic Medium
Let be a family of elliptic systems of linear
elasticity with rapidly oscillating periodic coefficients. We obtain the
uniform estimate in a Lipschitz domain for solutions to the Dirichlet
problem, where . The ranges of 's
are sharp for or 3
Hyperfine Spin-Two (F=2) Atoms in Three-Dimensional Optical Lattices: Phase Diagrams and Phase Transitions
We consider ultracold matter of spin-2 atoms in optical lattices. We derive
an effective Hamiltonian for the studies of spin ordering in Mott states and
investigate hyperfine spin correlations. Particularly, we diagonalize the
Hamiltonian in an on-site Hilbert space taking into account spin-dependent
interactions and exchange between different sites. We obtain phase diagrams and
quantum phase transitions between various magnetic phases.Comment: 10 pages, 10 figures, published versio
Quark charge balance function and hadronization effects in relativistic heavy ion collisions
We calculate the charge balance function of the bulk quark system before
hadronization and those for the directly produced and the final hadron system
in high energy heavy ion collisions. We use the covariance coefficient to
describe the strength of the correlation between the momentum of the quark and
that of the anti-quark if they are produced in a pair and fix the parameter by
comparing the results for hadrons with the available data. We study the
hadronization effects and decay contributions by comparing the results for
hadrons with those for the bulk quark system. Our results show that while
hadronization via quark combination mechanism slightly increases the width of
the charge balance functions, it preserves the main features of these functions
such as the longitudinal boost invariance and scaling properties in rapidity
space. The influence from resonance decays on the width of the balance function
is more significant but it does not destroy its boost invariance and scaling
properties in rapidity space either. The balance functions in azimuthal
direction are also presented.Comment: 9 figure
Tunable Quantum Fluctuation-Controlled Coherent Spin Dynamics
Temporal evolution of a macroscopic condensate of ultra cold atoms is usually
driven by mean field potentials, either due to scattering between atoms or due
to coupling to external fields; and coherent quantum dynamics have been
observed in various cold-atom experiments. In this article, we report results
of studies of a class of quantum spin dynamics which are purely driven by zero
point quantum fluctuations of spin collective coordinates. Unlike the usual
mean-field coherent dynamics, quantum fluctuation-controlled spin dynamics or
QFCSD studied here are very sensitive to variation of quantum fluctuations and
can be tuned by four to five order of magnitude using optical lattices. They
have unique dependence on optical lattice potential depths and quadratic Zeeman
fields. QFCSD can be potentially used to calibrate quantum fluctuations and
investigate correlated fluctuations and various universal scaling properties
near quantum critical points.Comment: 14 pages, 12 figures included; including detailed discussions on
thermal effects, trapping potentials and spin exchange losses. (To appear in
PRA
Quantum fluctuation-induced uniaxial and biaxial spin nematics
It is shown that zero point quantum fluctuations (ZPQFs) completely lift the
accidental continuous degeneracy that is found in mean field analysis of
quantum spin nematic phases of hyperfine spin 2 cold atoms. The result is two
distinct ground states which have higher symmetries: a uniaxial spin nematic
and a biaxial spin nematic with dihedral symmetry . There is a novel
first order quantum phase transition between the two phases as atomic
scattering lengths are varied. We find that the ground state of atoms
should be a uniaxial spin nematic. We note that the energy barrier between the
phases could be observable in dynamical experiments.Comment: 4 pages, 2 figures included; published versio
Quark number scaling of hadronic spectra and constituent quark degree of freedom in -Pb collisions at TeV
We show that the experimental data of spectra of identified hadrons
released recently by ALICE collaboration for -Pb collisions at
TeV exhibit a distinct universal behavior --- the quark
number scaling. We further show that the scaling is a direct consequence of
quark (re-)combination mechanism of hadronization and can be regarded as a
strong indication of the existence of the underlying source with constituent
quark degree of freedom for the production of hadrons in -Pb collisions at
such high energies. We make also predictions for production of other hadrons.Comment: 5 pages, 3 figure
- β¦