3,965 research outputs found
Sharp Bounds on Eigenvalues via Spectral Embedding Based on Signless Laplacians
Using spectral embedding based on the signless Laplacian, we obtain bounds on
the spectrum of transition matrices on graphs. As a consequence, we bound
return probabilities and the uniform mixing time of simple random walk on
graphs. In addition, spectral embedding is used in this article to bound the
spectrum of graph adjacency matrices. Our method is adapted from [Lyons and
Oveis Gharan, 2017].Comment: Comments are welcom
Production of the bottom analogues and the spin partner of the X(3872) at hadron colliders
Using the Monte Carlo event generator tools Pythia and Herwig, we simulate
the production of bottom/charm meson and antimeson pairs at hadron colliders in
proton-proton/antiproton collisions. With these results, we derive an
order-of-magnitude estimate for the production rates of the bottom analogues
and the spin partner of the as hadronic molecules at the LHC and
Tevatron experiments. We find that the cross sections for these processes are
at the nb level, so that the current and future data sets from the Tevatron and
LHC experiments offer a significant discovery potential. We further point out
that the should be reconstructed in the , , or instead of
the final states.Comment: 11 pages, 3 figures, updated calculation based on effective field
theory method, one author added, accepted by European Physics Journal
Number of Matchings of Low Order in (4,6)-Fullerene Graphs
We obtain the formulae for the numbers of 4-matchings and 5-matchings in
terms of the number of hexagonal faces in (4, 6)-fullerene graphs by studying
structural classification of 6-cycles and some local structural properties,
which correct the corresponding wrong results published. Furthermore, we obtain
a formula for the number of 6-matchings in tubular (4, 6)-fullerenes in terms
of the number of hexagonal faces, and a formula for the number of 6-matchings
in the other (4,6)-fullerenes in terms of the numbers of hexagonal faces and
dual-squares.Comment: This article was already published in 2017 in MATCH Commun. Math.
Comput. Chem. We are uploading it to arXiv for readers' convenienc
The masses and axial currents of the doubly charmed baryons
The chiral dynamics of the doubly heavy baryons is solely governed by the
light quark. In this work, We have derived the chiral corrections to the mass
of the doubly heavy baryons up to NLO. The mass splitting of and
at the NLO depends on one unknown low energy constant .
With the experimental mass of as the input, we estimate the
mass of to be around 3.678 GeV. Moreover, we have also performed
a systematical analysis of the chiral corrections to the axial currents and
axial charges of the doubly heavy baryons. The chiral structure and analytical
expressions will be very useful to the chiral extrapolations of the future
lattice QCD simulations of the doubly heavy baryons.Comment: 10 pages, 2 tables, 3 figure. Accepted by Phys. Rev.
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