5,330 research outputs found
The Possible J^{PC}=0^{--} Exotic State
In order to explore the possible existence of the exotic state, we
have constructed the tetraquark interpolating operators systematically. As a
byproduct, we notice the tetraquark operators without derivatives do
not exist. The special Lorentz structure of the currents forbids the
four-quark correction to the spectral density. Now the gluon condensate is the
dominant power correction. Within the framework of the finite energy sum rule,
none of the seven interpolating currents supports a resonant signal. Therefore
we conclude that the exotic state does not exist below 2 GeV, which is
consistent with the current experimental observations.Comment: 12 pages, 27 figure
Edge Roman domination on graphs
An edge Roman dominating function of a graph is a function satisfying the condition that every edge with
is adjacent to some edge with . The edge Roman
domination number of , denoted by , is the minimum weight
of an edge Roman dominating function of .
This paper disproves a conjecture of Akbari, Ehsani, Ghajar, Jalaly Khalilabadi
and Sadeghian Sadeghabad stating that if is a graph of maximum degree
on vertices, then . While the counterexamples having the edge Roman domination numbers
, we prove that is an upper bound for connected graphs. Furthermore, we
provide an upper bound for the edge Roman domination number of -degenerate
graphs, which generalizes results of Akbari, Ehsani, Ghajar, Jalaly Khalilabadi
and Sadeghian Sadeghabad. We also prove a sharp upper bound for subcubic
graphs.
In addition, we prove that the edge Roman domination numbers of planar graphs
on vertices is at most , which confirms a conjecture of
Akbari and Qajar. We also show an upper bound for graphs of girth at least five
that is 2-cell embeddable in surfaces of small genus. Finally, we prove an
upper bound for graphs that do not contain as a subdivision, which
generalizes a result of Akbari and Qajar on outerplanar graphs
Anderson Impurity in Helical Metal
We use a trial wave function to study the spin-1/2 Kondo effect of a helical
metal on the surface of a three-dimensional topological insulator. While the
impurity spin is quenched by conduction electrons, the spin-spin correlation of
the conduction electron and impurity is strongly anisotropic in both spin and
spatial spaces. As a result of strong spin-orbit coupling, the out-of-plane
component of the impurity spin is found to be fully screened by the orbital
angular momentum of the conduction electrons.Comment: The published versio
Generation of frequency multiplexed entangled single photons assisted by the entanglement
We present a scheme to generate the frequency multiplexed entangled (FME)
single photons based on the entanglement between two species atomic mixture
ensemble. The write and reads fields driven according to a certain timing
sequence, the generation of FME single photons can be repeated until success is
achieved. The source might have significant applications in wavelength division
multiplexing quantum key distribution.Comment: 4 pages, 4 figures, submitted to PR
Indeterminate Cell Histiocytosis: A Case Report
Indeterminate cell histiocytosis is a rare neoplasm composed of cells with mixed characteristics of Langerhans cells and non-Langerhans cells. An otherwise healthy, 36-year-old woman presented with asymptomatic generalized papules and nodules that had appeared on all four extremities, the trunk, and cheeks in the previous 6 months. The lesions were firm, painless, non-pruritic, and slightly flesh-yellow or reddish-brown in color. Histopathologic, immunohistochemical examination and electron microscopic studies showed characteristic findings of indeterminate cell histiocytosis: diffuse proliferative histiocytes infiltrating the dermis without epidermotropism or atypia; neoplastic cells expressing markers characteristic of both Langerhans cells (CD1a, S-100) and focal monocytes/macrophages (Factor XIIIa, CD68); and no Birbeck granules within the cytoplasm of the neoplastic cells. Flow cytometry revealed more CD34+ cells in the peripheral blood of the patient than in peripheral blood from a control. Interestingly, the patient responded favorably to psoralen ultraviolet A-range treatment. Herein, we present this case and review the literature
The Intergenerational Transmission of the Value of Children in Contemporary Chinese Families: Taiwan and Mainland China Compared
While fertility has been drastically declining in East Asia, mechanisms accounting for the current trend vary. One noticeable mechanism documented is that the changing value of children affects couples’ fertility decisions which in turn affect their subsequent fertility behaviour. This study will examine the intergenerational transmission of the value of children (VOC) among grandmothers, mothers and teenagers in two Chinese societies: Taiwan and Mainland China. We assume that cultural homogeneity interacts with political and social heterogeneity and may result in different values regarding having or not having children. Data are taken from two corresponding VOC surveys from Taiwan (2005-2007) and from Mainland China (2002-2003). We first compare the value of children for Taiwan and Mainland China with special attention to cultural aspects. Two identified factor solutions are generated for both positive (traditional and emotional) and negative (emotional/psychological and familial/social) VOC. Analyses show that intergenerational transmission of the VOC among three generations is more likely to occur for a positive VOC in the Chinese Mainland sample. We suspect that actual fertility experience results in greater resemblance on the VOC between grandmothers and mothers in both research settings. Among selected structural mechanisms, only rural-urban background has an effect on patterns of intergenerational transmission. The paper ends with a discussion on the importance of culture in explaining the intergenerational transmission of the VOC in Chinese societies.Dieser Beitrag liegt nur in englischer Sprache vor.While fertility has been drastically declining in East Asia, mechanisms accounting for the current trend vary. One noticeable mechanism documented is that the changing value of children affects couples’ fertility decisions which in turn affect their subsequent fertility behaviour. This study will examine the intergenerational transmission of the value of children (VOC) among grandmothers, mothers and teenagers in two Chinese societies: Taiwan and Mainland China. We assume that cultural homogeneity interacts with political and social heterogeneity and may result in different values regarding having or not having children. Data are taken from two corresponding VOC surveys from Taiwan (2005-2007) and from Mainland China (2002-2003). We first compare the value of children for Taiwan and Mainland China with special attention to cultural aspects. Two identified factor solutions are generated for both positive (traditional and emotional) and negative (emotional/psychological and familial/social) VOC. Analyses show that intergenerational transmission of the VOC among three generations is more likely to occur for a positive VOC in the Chinese Mainland sample. We suspect that actual fertility experience results in greater resemblance on the VOC between grandmothers and mothers in both research settings. Among selected structural mechanisms, only rural-urban background has an effect on patterns of intergenerational transmission. The paper ends with a discussion on the importance of culture in explaining the intergenerational transmission of the VOC in Chinese societies
Giant mesoscopic spin Hall effect on surface of topological insulator
We study mesoscopic spin Hall effect on the surface of topological insulator
with a step-function potential. The giant spin polarization induced by a
transverse electric current is derived analytically by using McMillan method in
the ballistic transport limit, which oscillates across the potential boundary
with no confinement from the potential barrier due to the Klein paradox, and
should be observable in spin resolved scanning tunneling microscope.Comment: 5 pages, 3 figure
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