4,403 research outputs found
Suppression of maximal linear gluon polarization in angular asymmetries
We perform a phenomenological analysis of the azimuthal
asymmetry in virtual photon plus jet production induced by the linear
polarization of gluons in unpolarized collisions. Although the linearly
polarized gluon distribution becomes maximal at small , TMD evolutionleads
to a Sudakov suppression of the asymmetry with increasing invariant mass of the
-jet pair. Employing a small- model input distribution, the
asymmetry is found to be strongly suppressed under TMD evolution, but still
remains sufficiently large to be measurable in the typical kinematical region
accessible at RHIC or LHC at moderate photon virtuality, whereas it is expected
to be negligible in -jet pair production at LHC. We point out the optimal
kinematics for RHIC and LHC studies, in order to expedite the first
experimental studies of the linearly polarized gluon distribution through this
process. We further argue that this is a particularly clean process to test the
-resummation formalism in the small- regime.Comment: 11 pages, 6 figure
Lacing topological orders in two dimensions: exactly solvable models for Kitaev's sixteen-fold way
A family of two-dimensional (2D) spin-1/2 models have been constructed to
realize Kitaev's sixteen-fold way of anyon theories. Defining a one-dimensional
(1D) path through all the lattice sites, and performing the Jordan-Wigner
transformation with the help of the 1D path, we find that such a spin-1/2 model
is equivalent to a model with species of Majorana fermions coupled to a
static gauge field. Here each specie of Majorana fermions gives
rise to an energy band that carries a Chern number , yielding a
total Chern number . It has been shown that the ground states
are three (four)-fold topologically degenerate on a torus, when is an odd
(even) number. These exactly solvable models can be achieved by quantum
simulations.Comment: 20 pages, 9 figure
Helicity hardens the gas
A screw generally works better than a nail, or a complicated rope knot better
than a simple one, in fastening solid matter, but a gas is more tameless.
However, a flow itself has a physical quantity, helicity, measuring the
screwing strength of the velocity field and the degree of the knottedness of
the vorticity ropes. It is shown that helicity favors the partition of energy
to the vortical modes, compared to others such as the dilatation and pressure
modes of turbulence; that is, helicity stiffens the flow, with nontrivial
implications for aerodynamics, such as aeroacoustics, and conducting fluids,
among others
Unveiling the Origin of Charge Transport in SrTiO_3 Beyond the Quasiparticle Regime
In materials with strong electron-phonon (e-ph) interactions, the electrons carry a phonon cloud during their motion, forming quasiparticles known as polarons. Charge transport and its temperature dependence in the polaron regime remain poorly understood. Here, we present first-principles calculations of charge transport in a prototypical material with large polarons, SrTiO_3. Using a cumulant diagram-resummation technique that can capture the strong e-ph interactions, our calculations can accurately predict the experimental electron mobility in SrTiO_3 between 150−300 K. They further reveal that for increasing temperature the charge transport mechanism transitions from band-like conduction, in which the scattering of renormalized quasiparticles is dominant, to an incoherent transport regime governed by dynamical interactions between the electrons and their phonon cloud. Our work reveals long-sought microscopic details of charge transport in SrTiO_3, and provides a broadly applicable method for predicting charge transport in materials with strong e-ph interactions and polarons
Regional economic status inference from information flow and talent mobility
Novel data has been leveraged to estimate socioeconomic status in a timely
manner, however, direct comparison on the use of social relations and talent
movements remains rare. In this letter, we estimate the regional economic
status based on the structural features of the two networks. One is the online
information flow network built on the following relations on social media, and
the other is the offline talent mobility network built on the anonymized resume
data of job seekers with higher education. We find that while the structural
features of both networks are relevant to economic status, the talent mobility
network in a relatively smaller size exhibits a stronger predictive power for
the gross domestic product (GDP). In particular, a composite index of
structural features can explain up to about 84% of the variance in GDP. The
result suggests future socioeconomic studies to pay more attention to the
cost-effective talent mobility data.Comment: 7 pages, 5 figures, 2 table
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