118 research outputs found
Spin Hydrodynamic Generation in the Charged Subatomic Swirl
Recently there have been significant interests in the spin hydrodynamic
generation phenomenon from multiple disciplines of physics. Such phenomenon
arises from global polarization effect of microscopic spin by macroscopic fluid
rotation and is expected to occur in the hot quark-gluon fluid (the ``subatomic
swirl'') created in relativistic nuclear collisions. This was indeed discovered
in experiments which however revealed an intriguing puzzle: a polarization
difference between particles and anti-particles. We suggest a novel application
of a general connection between rotation and magnetic field: a magnetic field
naturally arises along the fluid vorticity in the charged subatomic swirl. We
establish this mechanism as a new way for generating long-lived in-medium
magnetic field in heavy ion collisions. Due to its novel feature, this new
magnetic field provides a nontrivial explanation to the puzzling observation of
a difference in spin hydrodynamic generation for particles and anti-particles
in heavy ion collisions.Comment: 10 pages, 3 figures, title changed according to published versio
The absence of mixed valency for Pr in pristine and hole-doped PrNiO
Infinite-layer nickelates (NiO) exhibit some distinct differences as
compared to cuprate superconductors, leading to a debate concerning the role of
rare-earth ions (=La, Pr, Nd) in the low-energy many-body physics. Although
rare-earth orbitals are typically treated as inert `core' electrons in
studies, this approximation has been questioned. An active participation of
states is most likely for PrNiO based on an analogy to cuprates where
Pr cuprates differ significantly from other cuprates. Here, we adopt density
functional plus dynamical mean field theory (DFT+DMFT) to investigate the role
of Pr orbitals and more generally the correlated electronic structure of
PrNiO and its hole-doped variant. We find that the Pr states are
insulating and show no evidence for either a Kondo resonance or Zhang-Rice
singlet formation as they do not have any hybridization channels near the Fermi
energy. The biggest effects of hole doping are to shift the Pr and
states further away from the Fermi energy while enhancing the Ni - O
hybridization, thus reducing correlation effects as the O states get
closer to the Fermi energy. We again find no evidence for either Kondo or
Zhang-Rice physics for the states upon hole doping. We conclude by
commenting on implications for other reduced valence nickelates.Comment: 12 pages, 13 figure
Medium-Assisted Enhancement of Production from Small to Large Colliding Systems
Studies of exotic hadrons such as the state provide
crucial insights into the fundamental force governing the strong interaction
dynamics, with an emerging new frontier to investigate their production in high
energy collisions where a partonic medium is present. Latest experimental
measurements from the Large Hadron Collider show an intriguing evolution
pattern of the -to- yield ratio from proton-proton
collisions with increasing multiplicities toward proton-lead and lead-lead
collisions. Here we propose a novel mechanism of medium-assisted enhancement
for the production, which competes with the more
conventional absorption-induced suppression and results in a non-monotonic
trend from small to large colliding systems. Realistic simulations from this
model offer the first quantitative description of all available data.
Predictions are made for the centrality dependence of this observable in PbPb
collisions as well as for its system size dependence from OO and ArAr to XeXe
and PbPb collisions. In both cases, a non-monotonic behavior emerges as the
imprint of the competition between enhancement and suppression and can be
readily tested by future data.Comment: 7 pages, 4 figure
Seismic Data Strong Noise Attenuation Based on Diffusion Model and Principal Component Analysis
Seismic data noise processing is an important part of seismic exploration
data processing, and the effect of noise elimination is directly related to the
follow-up processing of data. In response to this problem, many authors have
proposed methods based on rank reduction, sparse transformation, domain
transformation, and deep learning. However, such methods are often not ideal
when faced with strong noise. Therefore, we propose to use diffusion model
theory for noise removal. The Bayesian equation is used to reverse the noise
addition process, and the noise reduction work is divided into multiple steps
to effectively deal with high-noise situations. Furthermore, we propose to
evaluate the noise level of blind Gaussian seismic data using principal
component analysis to determine the number of steps for noise reduction
processing of seismic data. We train the model on synthetic data and validate
it on field data through transfer learning. Experiments show that our proposed
method can identify most of the noise with less signal leakage. This has
positive significance for high-precision seismic exploration and future seismic
data signal processing research.Comment: 10 pages, 13 figures. This work has been submitted to the IEEE for
possible publication. Copyright may be transferred without notice, after
which this version may no longer be accessibl
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