4,922 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
Fractionalization and Anomalies in Symmetry-Enriched U(1) Gauge Theories
We classify symmetry fractionalization and anomalies in a (3+1)d U(1) gauge
theory enriched by a global symmetry group . We find that, in general, a
symmetry-enrichment pattern is specified by 4 pieces of data: , a map
from to the duality symmetry group of this gauge theory
which physically encodes how the symmetry permutes the fractional excitations,
, the symmetry actions
on the electric charge, ,
indication of certain domain wall decoration with bosonic integer quantum Hall
(BIQH) states, and a torsor over , the
symmetry actions on the magnetic monopole. However, certain choices of are not physically realizable, i.e. they are anomalous. We find
that there are two levels of anomalies. The first level of anomalies obstruct
the fractional excitations being deconfined, thus are referred to as the
deconfinement anomaly. States with these anomalies can be realized on the
boundary of a (4+1)d long-range entangled state. If a state does not suffer
from a deconfinement anomaly, there can still be the second level of anomaly,
the more familiar 't Hooft anomaly, which forbids certain types of symmetry
fractionalization patterns to be implemented in an on-site fashion. States with
these anomalies can be realized on the boundary of a (4+1)d short-range
entangled state. We apply these results to some interesting physical examples.Comment: are welcome; v2 references adde
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
Large eddy simulation of turbulent flows with property variations, rotation and complex geometry
A compressible finite volume formulation for large eddy simulation has been extended to solve a variety of flows by using dynamic subgrid-scale stress model and dynamic Prandtl number model. The basic features of this finite volume formulation include a dual time stepping approach with time derivative preconditioning, an implicit low-upper symmetric Gauss-Seidel scheme, multiblock framework, and parallelization using message passing interface;Implementation of the dynamic model is validated by simulating a plane channel flow with constant heat flux. Good agreement between the present results and benchmark results in the literature is observed. Rotating channel flows with heat transfer are studied by adding a rotation source term. The effects of system rotation on the turbulent heat transfer are investigated. Finally, a rib-roughened channel flow is simulated both with and without heat transfer;The large eddy formulation with a dynamic model generally provided excellent agreement with direct numerical simulation results and experimental results for turbulent flows with heat transfer. For the constant heat flux channel flows, high heating tends to reduce the velocity fluctuations, while high cooling tends to enhance the fluctuations. The mean and fluctuation velocity profiles approach the incompressible results when normalized by local properties, as opposed to wall values. Spanwise system rotation is found to suppress turbulent velocity fluctuations and shear stresses near the stable side of the channel, but enhance the fluctuations and shear stresses near the unstable side. Turbulent temperature fluctuations and turbulent heat flux decreased near the stable side of the channel, but increased near the unstable side of the channel. In the case of the rib-roughened channel flow, a small recirculation zone before the rib and a larger recirculation zone after the rib are observed. Increased turbulent fluctuations and heat transfer are found around the rib
Surface diffuseness correction in global mass formula
By taking into account the surface diffuseness correction for unstable
nuclei, the accuracy of the macroscopic-microscopic mass formula is further
improved. The rms deviation with respect to essentially all the available mass
data falls to 298 keV, crossing the 0.3 MeV accuracy threshold for the first
time within the mean-field framework. Considering the surface effect of the
symmetry potential which plays an important role in the evolution of the
"neutron skin" toward the "neutron halo" of nuclei approaching the neutron drip
line, we obtain an optimal value of the symmetry energy coefficient J=30.16
MeV. With an accuracy of 258 keV for all the available neutron separation
energies and of 237 keV for the alpha-decay Q-values of super-heavy nuclei, the
proposed mass formula is particularly important not only for the reliable
description of the r-process of nucleosynthesis but also for the study of the
synthesis of super-heavy nuclei.Comment: 2 figures, 2 tables, to appear in Phys. Lett.
Lesbians and Their Mothers: A Taiwanese Experience
Many studies, both in the United States and in Taiwan, have explored how the coming-out experience influenced LGBT individuals and their families, and some studies have also addressed how their familial relationships have been shaped because of the experience. As a Taiwanese who has studied family therapy in the United States, my personal experience as well as research and professional interest brought me to conduct this qualitative study focusing on the experience of coming out in mother-daughter relationships in Taiwan. Nine dyads of mothers and daughters were interviewed and provided their retrospective accounts of their experience of disclosure and how they made meaning of this particular experience. Both parties shared their perspectives on the process of coming out, and mothers addressed their process of acceptance as well as other family members\u27 reactions. Results indicated that disclosure could be seen as a special event that was embedded and then processed in the mother-daughter relationship; therefore the nature of the parent-child relationship was very influential in how the disclosure was treated. In addition, Confucianism beliefs address the importance of the role of each family member, and these beliefs appear to influence how mothers and daughters interact and shape their relationship. Also, family dynamics had a great impact on these dyads\u27 experience of coming out and mothers\u27 levels of acceptance, which resonated with previous findings that family values are crucial to people from Asian cultural heritage. Rather than focusing on preparing a perfect disclosure event, it seems as if therapists should pay more attention to disclosure and acceptance as an ongoing process
Soft-Defined Heterogeneous Vehicular Network: Architecture and Challenges
Heterogeneous Vehicular NETworks (HetVNETs) can meet various
quality-of-service (QoS) requirements for intelligent transport system (ITS)
services by integrating different access networks coherently. However, the
current network architecture for HetVNET cannot efficiently deal with the
increasing demands of rapidly changing network landscape. Thanks to the
centralization and flexibility of the cloud radio access network (Cloud-RAN),
soft-defined networking (SDN) can conveniently be applied to support the
dynamic nature of future HetVNET functions and various applications while
reducing the operating costs. In this paper, we first propose the multi-layer
Cloud RAN architecture for implementing the new network, where the multi-domain
resources can be exploited as needed for vehicle users. Then, the high-level
design of soft-defined HetVNET is presented in detail. Finally, we briefly
discuss key challenges and solutions for this new network, corroborating its
feasibility in the emerging fifth-generation (5G) era
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