4,857 research outputs found
Probing Triple-W Production and Anomalous WWWW Coupling at the CERN LHC and future 100TeV proton-proton collider
Triple gauge boson production at the LHC can be used to test the robustness
of the Standard Model and provide useful information for VBF di-boson
scattering measurement. Especially, any derivations from SM prediction will
indicate possible new physics. In this paper we present a detailed Monte Carlo
study on measuring WWW production in pure leptonic and semileptonic decays, and
probing anomalous quartic gauge WWWW couplings at the CERN LHC and future
hadron collider, with parton shower and detector simulation effects taken into
account. Apart from cut-based method, multivariate boosted decision tree method
has been exploited for possible improvement. For the leptonic decay channel,
our results show that at the sqrt{s}=8(14)[100] TeV pp collider with integrated
luminosity of 20(100)[3000] fb-1, one can reach a significance of
0.4(1.2)[10]sigma to observe the SM WWW production. For the semileptonic decay
channel, one can have 0.5(2)[14]sigma to observe the SM WWW production. We also
give constraints on relevant Dim-8 anomalous WWWW coupling parameters.Comment: Accepted version by JHE
Beyond the mixture of generalized Pauli dephasing channels
In recent times, there has been a growing scholarly focus on investigating
the intricacies of quantum channel mixing. It has been commonly believed, based
on intuition in the literature, that every generalized Pauli channel with
dimensionality could be represented as a convex combination of
generalized Pauli dephasing channels (see [Phys. Rev. A 103, 022605 (2021)] as
a reference). To our surprise, our findings indicate the inaccuracy of this
intuitive perspective. This has stimulated our interest in exploring the
properties of convex combinations of generalized Pauli channels, beyond the
restriction to just generalized Pauli dephasing channels. We
demonstrate that many previously established properties still hold within this
broader context. For instance, any mixture of invertible generalized Pauli
channels retains its invertibility. It's worth noting that this property
doesn't hold when considering the Weyl channels setting. Additionally, we
demonstrate that every Pauli channel (for the case of ) can be represented
as a mixture of Pauli dephasing channels, but this generalization
doesn't apply to higher dimensions. This highlights a fundamental distinction
between qubit and general qudit cases. In contrast to prior understanding, we
show that non-invertibility of mixed channels is not a prerequisite for the
resulting mapping to constitute a Markovian semigroup.Comment: 9 pages, 2 figure
Machine-learning-inspired quantum optimal control of nonadiabatic geometric quantum computation via reverse engineering
Quantum control plays an irreplaceable role in practical use of quantum
computers. However, some challenges have to be overcome to find more suitable
and diverse control parameters. We propose a promising and generalizable
average-fidelity-based machine-learning-inspired method to optimize the control
parameters, in which a neural network with periodic feature enhancement is used
as an ansatz. In the implementation of a single-qubit gate by cat-state
nonadiabatic geometric quantum computation via reverse engineering, compared
with the control parameters in the simple form of a trigonometric function, our
approach can yield significantly higher-fidelity () phase gates, such
as the gate (T gate). Single-qubit gates are robust against
systematic noise, additive white Gaussian noise and decoherence. We numerically
demonstrate that the neural network possesses the ability to expand the model
space. With the help of our optimization, we provide a feasible way to
implement cascaded multi-qubit gates with high quality in a bosonic system.
Therefore, the machine-learning-inspired method may be feasible in quantum
optimal control of nonadiabatic geometric quantum computation.Comment: 12 pages, 8 figure
Cross-cultural validation of the Health Care Provider HIV/AIDS Stigma Scale (HPASS) in China
The study aimed to validate the Health Care Provider HIV/AIDS Stigma Scale among medical staff in China. The validation was conducted in four steps from March to December 2017: translation and back-translation; content validity test with six experts; test–retest reliability testing with 63 medical staff with 2 weeks interval; and structural validation with 349 medical staff from 52 hospitals with a convenience sample,using exploratory factor analysis,including principal component analysis and varimax rotation. The scale content validity index average was 0.88, while for test–retest reliability, the ICC was 0.87. Three factors of “discrimination”, “prejudice” and “stereotype” with 16 items were extracted and explained 59.61% variance. The Cronbach’s alpha value for the total scale was of 0.88, and for the three factors, the values were 0.89, 0.86 and 0.74, respectively. The discrimination factor showed identical means between Canadian medical students and Chinese medical staff, while the prejudice and stereotype factors had higher mean scores in the Chinese sample. The three-factor structure of Health Care Provider HIV/AIDS Stigma Scale was confirmed in Chinese medical staff with a simpler solution. This could provide a basis for trans-cultural application and comparison
Witnessing quantum coherence with prior knowledge of observables
Quantum coherence is the key resource in quantum technologies including
faster computing, secure communication and advanced sensing. Its quantification
and detection are, therefore, paramount within the context of quantum
information processing. Having certain priori knowledge on the observables may
enhance the efficiency of coherence detection. In this work, we posit that the
trace of the observables is a known quantity. Our investigation confirms that
this assumption indeed extends the scope of coherence detection capabilities.
Utilizing this prior knowledge of the trace of the observables, we establish a
series of coherence detection criteria. We investigate the detection
capabilities of these coherence criteria from diverse perspectives and
ultimately ascertain the existence of four distinct and inequivalent criteria.
These findings contribute to the deepening of our understanding of coherence
detection methodologies, thereby potentially opening new avenues for
advancements in quantum technologies.Comment: 9 pages, 3 figure
Insights into the Ecological Roles and Evolution of Methyl-Coenzyme M Reductase-Containing Hot Spring Archaea
Several recent studies have shown the presence of genes for the key enzyme associated with archaeal methane/alkane metabolism, methyl-coenzyme M reductase (Mcr), in metagenome-assembled genomes (MAGs) divergent to existing archaeal lineages. Here, we study the mcr-containing archaeal MAGs from several hot springs, which reveal further expansion in the diversity of archaeal organisms performing methane/alkane metabolism. Significantly, an MAG basal to organisms from the phylum Thaumarchaeota that contains mcr genes, but not those for ammonia oxidation or aerobic metabolism, is identified. Together, our phylogenetic analyses and ancestral state reconstructions suggest a mostly vertical evolution of mcrABG genes among methanogens and methanotrophs, along with frequent horizontal gene transfer of mcr genes between alkanotrophs. Analysis of all mcr-containing archaeal MAGs/genomes suggests a hydrothermal origin for these microorganisms based on optimal growth temperature predictions. These results also suggest methane/alkane oxidation or methanogenesis at high temperature likely existed in a common archaeal ancestor
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