25,368 research outputs found
Deuteron-like states composed of two doubly charmed baryons
We present a systematic investigation of the possible molecular states
composed of a pair of doubly charmed baryons () or one doubly
charmed baryon and one doubly charmed antibaryon
within the framework of the one-boson-exchange-potential model. For the
spin-triplet systems, we take into account the mixing between the and
channels. For the baryon-baryon system with and , where and represent the group
representation and the isospin of the system, respectively, there exist loosely
bound molecular states. For the baryon-antibaryon system
with , and , there
also exist deuteron-like molecules. The molecular states
may be produced at LHC. The proximity of their masses to the threshold of two
doubly charmed baryons provides a clean clue to identify them.Comment: 18 pages, 8 figure
Possible hadronic molecules composed of the doubly charmed baryon and nucleon
We perform a systematical investigation of the possible deuteron-like bound
states with configuration , where denotes the
nucleon (anti-nucleon), in the framework of the one-boson-exchange-potential
model. In the spin-triplet sector we take into account both the and
channels due to non-vanishing tensor force. There exist several
candidates of the loosely bound molecular states for the and
systems, which lie below the threshold of
or . We also investigate the
possible loosely bound states with configurations and
. These molecular candidates may be searched for at Belle
II and LHC in the near future.Comment: 14 pages, 5 figure
Monitoring Scheme for Safety Hazard Status of Urban Rail Transit Operation Equipment and Facilities Based on Blockchain Technology
Urban rail transit plays a very important role in cities’ social and economic development. To ensure the safe and stable operation of urban rail transit operation equipment and facilities, it is necessary to monitor a large number of safety hazard statuses and data and improve the over-centralisation of traditional monitoring. This paper designs a scheme for storing, validating and monitoring the safety hazard status of urban rail transit operation equipment and facilities based on blockchain technology. The safety hazards of equipment and facilities during the operation stage of urban rail transit are listed using the literature analysis method and the case study method. The European RAMS (reliability, availability, maintainability and safety) standard method is used to determine the safety hazard status of equipment and facilities by availability index. Based on the features of the consensus mechanism, smart contract and other features of blockchain technology, this paper designs an overall scheme for storing, verifying and monitoring the safety hazard status of equipment and facilities. This scheme provides a practical operation method for evaluating the safety hazard status of rail transit equipment and facilities, which is conducive to the safety rectification of the entire urban rail transit
Double spike Dirichlet priors for structured weighting
Assigning weights to a large pool of objects is a fundamental task in a wide
variety of applications. In this article, we introduce a concept of structured
high-dimensional probability simplexes, whose most components are zero or near
zero and the remaining ones are close to each other. Such structure is well
motivated by 1) high-dimensional weights that are common in modern
applications, and 2) ubiquitous examples in which equal weights -- despite
their simplicity -- often achieve favorable or even state-of-the-art predictive
performances. This particular structure, however, presents unique challenges
both computationally and statistically. To address these challenges, we propose
a new class of double spike Dirichlet priors to shrink a probability simplex to
one with the desired structure. When applied to ensemble learning, such priors
lead to a Bayesian method for structured high-dimensional ensembles that is
useful for forecast combination and improving random forests, while enabling
uncertainty quantification. We design efficient Markov chain Monte Carlo
algorithms for easy implementation. Posterior contraction rates are established
to provide theoretical support. We demonstrate the wide applicability and
competitive performance of the proposed methods through simulations and two
real data applications using the European Central Bank Survey of Professional
Forecasters dataset and a UCI dataset
Magnetic moments of the spin- doubly heavy baryons
In this work, we investigate the chiral corrections to the magnetic moments
of the spin- doubly charmed baryons systematically up to
next-to-next-to-leading order with the heavy baryon chiral perturbation theory.
The numerical results are given up to next-to-leading order:
, ,
. As a by-product, we have also calculated
the magnetic moments of the spin- doubly bottom baryons and charmed
bottom baryons:
, ,
, ,
, .Comment: 10 pages,2 figures. arXiv admin note: text overlap with
arXiv:1707.02765. Replace the published versio
Radiative decays of the doubly charmed baryons in chiral perturbation theory
We have systematically investigated the spin- to
spin- doubly charmed baryon transition magnetic moments to the
next-to-next-to-leading order in the heavy baryon chiral perturbation theory
(HBChPT). Numerical results of transition magnetic moments and decay widths are
presented to the next-to-leading order:
,
,
,
keV,
keV,
keV.Comment: arXiv admin note: text overlap with arXiv:1707.02765,
arXiv:1706.0645
Pain Sensitivity Associated With the Length of the Maximum Interblink Period.
Pain sensitivity has been identified as a factor that affects how individuals answer dry eye questionnaires, but it is unknown how it affects ocular discomfort. This study used the time that individuals could refrain from blinking as an indicator of ocular discomfort and set out to determine whether it was related to pain sensitivity, while adjusting for ocular surface conditions.Subjects first completed the Pain Sensitivity Questionnaire to quantify pain sensitivity levels. Exposed interpalpebral area, tear meniscus height, tear-film lipid layer thickness, ocular surface cooling, and noninvasive tear breakup were assessed. Subjects were then asked to refrain from blinking until the initial onset of discomfort, which was termed "the maximum interblink period" (MIBP), while ocular surface cooling rate was simultaneously measured. Subjects were seen for four visits over a course of 2 days.Forty-two subjects (36 females, 6 males) completed the study, with a mean (SD) age of 23.2 (3.8) years. A longer MIBP was associated with decreased pain sensitivity (P = 0.04), lower ocular surface cooling rate (P < 0.001), and Asian ethnicity (P = 0.005). Based on the results from the mixed-effect model, it is estimated that individuals would be able to refrain from blinking for an additional 4 seconds if they had the lowest (0.6) compared to the highest (6.1) pain sensitivity in the study cohort.The Pain Sensitivity Questionnaire was associated with the MIBP length even after adjusting for ocular surface conditions, which suggests that pain sensitivity plays a role in influencing how ocular discomfort is perceived
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