1,722,202 research outputs found
Faddeev fixed-center approximation to the , and systems
Get PDFThe three-body , and
systems are investigated within the framework of fixed-center approximation to
the Faddeev equations, where is treated as the scalar meson
. The interactions between , , and are taking
from the chiral unitary approach. By scattering the meson on the
clusterized system, we find a peak in the modulus
squared of the three-body scattering amplitude and it can be associated as a
bound state with quantum numbers . Its mass and width
are around 2054 MeV and 60 MeV, respectively. This state could be associated to
the meson. For the scattering, we
find a bump structure around 1900-2000 MeV with quantum numbers
. While for the system, there are
three structures. One of them is much stable and its mass is about 2130 MeV. It
is expected that these theoretical predictions here could be tested by future
experimental measurements, such as by the BESIII, BelleII and LHCb
collaborations.Comment: 10 pages, 15 figure
Further results on bar k-visibility graphs
No full textA bar visibility representation of a graph G is a collection of horizontal bars in the plane corresponding to the vertices of G such that two vertices are adjacent if and only if the corresponding bars can be joined by an unobstructed vertical line segment. In a bar k-visibility graph, two vertices are adjacent if and only if the corresponding bars can be joined by a vertical line segment that intersects at most k other bars. Bar k-visibility graphs were introduced by Dean, Evans, Gethner, Laison, Safari, and Trotter in [3]. In this paper, we present sharp upper bounds on the maximum number of edges in a bar k-visibility graph on n vertices and the largest order of a complete bar k-visibility graph. We also discuss regular bar k-visibility graphs and forbidden induced subgraphs of bar k-visibility graphs
Further results on bar k-visibility graphs
No full textAbstract. A bar visibility representation of a graph G is a collection of horizontal bars in the plane corresponding to the vertices of G such that two vertices are adjacent if and only if the corresponding bars can be joined by an unobstructed vertical line segment. In a bar k-visibility graph, two vertices are adjacent if and only if the corresponding bars can be joined by a vertical line segment that intersects at most k other bars. Bar k-visibility graphs were introduced by Dean et al. [J. Graph Algorithms Appl., 11 (2007), pp. 45–59]. In this paper, we present sharp upper bounds on the maximum number of edges in a bar k-visibility graph on n vertices and the largest order of a complete bar k-visibility graph. We also discuss regular bar k-visibility graphs and forbidden induced subgraphs of bar k-visibility graphs
Observation of and measurement of the effective couplings of to and
No full textUsing , , and data collected by
the Belle detector, we discover a new resonant three-body decay
with a significance of
5.2. The mass of the is MeV and
its effective couplings to and are
and , where
the first uncertainties are statistical and the second are systematic. The
ratio of the branching fraction for the resonant three-body decay to that for
the two-body decay to is , consistent with the
molecular model of , which predicts comparable rates for
decay to and .Comment: 4 pages, 2 figure
Bar k-Visibility Graphs
No full textLet S be a set of horizontal line segments, or bars, in the plane. We say that G is a bar visibility graph, and S its bar visibility representation, if there exists a one-to-one correspondence between vertices of G and bars in S, such that there is an edge between two vertices in G if and only if there exists an unobstructed vertical line of sight between their corresponding bars. If bars are allowed to see through each other, the graphs representable in this way are precisely the interval graphs. We consider representations in which bars are allowed to see through at most k other bars. Since all bar visibility graphs are planar, we seek measurements of closeness to planarity for bar k-visibility graphs. We obtain an upper bound on the number of edges in a bar k-visibility graph. As a consequence, we obtain an upper bound of 12 on the chromatic number of bar 1-visibility graphs, and a tight upper bound of 8 on the size of the largest complete bar 1-visibility graph. We also consider the thickness of bar k-visibility graphs, obtaining an upper bound of 4 when k = 1, and a bound that is quadratic in k for k> 1
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Theoretical study of scalar meson in the reaction
Get PDFWe investigate the process by taking into
account the -wave and interactions within the
unitary coupled-channel approach, where the scalar meson is
dynamically generated. In addition, the contributions from the intermediate
resonances and are also considered. We find a significant dip structure around
1.8~GeV, associated to the , in the invariant
mass distribution, and the clear peaks of the in the
and invariant mass distributions, consistent with
the {\it BABAR} measurements. We further estimate the branching fractions
and
. Our predictions
can be tested by the BESIII and BelleII experiments in the future.Comment: 9 pages, 9 figure
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Measurement of the Branching Ratio for D{sup +} {yields} {bar K}*(892){degrees} {mu}{sup +}{nu}
No full textThe branching ratio for the decay mode D{sup +} {yields} {bar K}*{sup 0} {mu}{sup +}{nu} has been measured with two methods. The first uses D{sup 0} {yields} {bar K} {sup {minus}}{mu}{sup +}{nu} for normalization, and yields the result B(D{sup +} {yields} {bar K}*{sup 0} {mu}{sup +}{nu} = (3.25 {plus_minus} 0.71 {plus_minus} 0.75)%. From this method we also obtain the direct measurement {Gamma}(D{sup +} {yields}{bar K}*{sup 0}{mu}{sup +} {nu}/{Gamma}(D{sup 0} {yields} K{sup {minus}} {mu}{sup +} {nu}) = 0.43 {plus_minus} 0.09 {plus_minus} 0.09. The second method uses the mode D{sup +} {yields} K{sup {minus}}{pi}{sup +} {pi}{sup +} for normalization and yields B(D{sup +} {yields} {bar K}*{sup 0} {mu}{sup +}{nu}) = 4.18 {plus_minus} 0.66 {plus_minus}0.96)%. Combining the results of the two methods yields B(D{sup +} {yields} {bar K}*{sup 0}{mu}{sup +}{nu}) = 3.57 {plus_minus} 0.96)%
Molecular states of nature
Get PDFWe study the interaction of two and a by using the
Fixed Center Approximation to the Faddeev equations to search for bound states
of the three body system. Since the interaction is attractive and
gives a bound state, and so is the case of the interaction,
where the bound state is identified with the , the system leads to manifestly exotic bound states with
open quarks. We obtain bound states of isospin , negative parity and
total spin . For we obtain one state, and for we obtain
two states in each case. The binding energies range from MeV to MeV
and the widths from MeV to MeV.Comment: 19 pages, 7 figures, 1 table, version published in Phys Rev
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