2,717 research outputs found
Probing Transverse Momentum Broadening via Dihadron and Hadron-jet Angular Correlations in Relativistic Heavy-ion Collisions
Dijet, dihadron, hadron-jet angular correlations have been reckoned as
important probes of the transverse momentum broadening effects in relativistic
nuclear collisions. When a pair of high-energy jets created in hard collisions
traverse the quark-gluon plasma produced in heavy-ion collisions, they become
de-correlated due to the vacuum soft gluon radiation associated with the
Sudakov logarithms and the medium-induced transverse momentum broadening. For
the first time, we employ the systematical resummation formalism and establish
a baseline calculation to describe the dihadron and hadron-jet angular
correlation data in and peripheral collisions where the medium effect
is negligible. We demonstrate that the medium-induced broadening and the so-called jet quenching parameter can be
extracted from the angular de-correlations observed in collisions. A
global analysis of dihadron and hadron-jet angular correlation data
renders the best fit for a
quark jet at RHIC top energy. Further experimental and theoretical efforts
along the direction of this work shall significantly advance the quantitative
understanding of transverse momentum broadening and help us acquire
unprecedented knowledge of jet quenching parameter in relativistic heavy-ion
collisions.Comment: 6 pages, 3 figure
On the Over-Memorization During Natural, Robust and Catastrophic Overfitting
Overfitting negatively impacts the generalization ability of deep neural
networks (DNNs) in both natural and adversarial training. Existing methods
struggle to consistently address different types of overfitting, typically
designing strategies that focus separately on either natural or adversarial
patterns. In this work, we adopt a unified perspective by solely focusing on
natural patterns to explore different types of overfitting. Specifically, we
examine the memorization effect in DNNs and reveal a shared behaviour termed
over-memorization, which impairs their generalization capacity. This behaviour
manifests as DNNs suddenly becoming high-confidence in predicting certain
training patterns and retaining a persistent memory for them. Furthermore, when
DNNs over-memorize an adversarial pattern, they tend to simultaneously exhibit
high-confidence prediction for the corresponding natural pattern. These
findings motivate us to holistically mitigate different types of overfitting by
hindering the DNNs from over-memorization natural patterns. To this end, we
propose a general framework, Distraction Over-Memorization (DOM), which
explicitly prevents over-memorization by either removing or augmenting the
high-confidence natural patterns. Extensive experiments demonstrate the
effectiveness of our proposed method in mitigating overfitting across various
training paradigms
Landau-Zener-St\"{u}ckelberg Interference of Microwave Dressed States of a Superconducting Phase Qubit
We present the first observation of Landau-Zener-St\"{u}ckelberg (LZS)
interference of the dressed states arising from an artificial atom, a
superconducting phase qubit, interacting with a microwave field. The dependence
of LZS interference fringes on various external parameters and the initial
state of the qubit agrees quantitatively very well with the theoretical
prediction. Such LZS interferometry between the dressed states enables us to
control the quantum states of a tetrapartite solid-state system with ease,
demonstrating the feasibility of implementing efficient multipartite quantum
logic gates with this unique approach.Comment: 6 pages, 3 figures To appear in Physical Review B(R
2-(4-tert-ButylÂphenÂyl)-5-{3,4-dibutoxy-5-[5-(4-tert-butylÂphenÂyl)-1,3,4-oxadiazol-2-yl]-2-thienyl}-1,3,4-oxadiazole
In the title compound, C36H44N4O4S, the dihedral angles between the central thioÂphene ring and the pendent oxadiazole rings are 12.7 (2) and 13.7 (2)°, and the dihedral angles between the oxadiazole rings and their adjacent benzene rings are 6.1 (2) and 17.5 (2)°. An intraÂmolecular C—H⋯O interÂaction may help to establish the conformation
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