10,653 research outputs found
The fluctuations of the giant cluster for percolation on random split trees
A split tree of cardinality is constructed by distributing "balls" in
a subset of vertices of an infinite tree which encompasses many types of random
trees such as -ary search trees, quad trees, median-of- trees,
fringe-balanced trees, digital search trees and random simplex trees. In this
work, we study Bernoulli bond percolation on arbitrary split trees of large but
finite cardinality . We show for appropriate percolation regimes that depend
on the cardinality of the split tree that there exists a unique giant
cluster, the fluctuations of the size of the giant cluster as are described by an infinitely divisible distribution that belongs to
the class of stable Cauchy laws. This work generalizes the results for the
random -ary recursive trees in Berzunza (2015). Our approach is based on a
remarkable decomposition of the size of the giant percolation cluster as a sum
of essentially independent random variables which may be useful for studying
percolation on other trees with logarithmic height; for instance in this work
we study also the case of regular trees.Comment: 43 page
Isospin symmetry breaking of K and K* mesons
We use the method of QCD sum rules to investigate the isospin symmetry
breaking of K and K* mesons. The electromagnetic effect, difference between up
and down current-quark masses and difference between up and down quark
condensates are important. We perform sum rule analyses of their masses and
decay constant differences, which are consistent with experimental values. Our
results yield Delta f_K = f_{K^0} - f_{K^\pm} = 1.5 MeV.Comment: 9 pages, 7 figures, one reference adde
Light Scalar Mesons in the QCD Sum Rule
We study the light scalar mesons in the QCD sum rule. We find that there are
five independent scalar tetraquark currents in the local form, and we perform
QCD sum rule analysis using both these currents and their combinations.
Compared with the sum rules by conventional \bar{q} q currents, our result
supports a tetraquark structure for low-lying scalar mesons.Comment: 4 pages, 1 figure. Talk given at the Yukawa International Seminar
(YKIS) 2006, "New frontiers in QCD", Kyoto, Japan, 20 Nov. - 8 Dec. 200
Weak Decays of Doubly Heavy Baryons: Multi-body Decay Channels
The newly-discovered decays into the , but the experimental data has indicated that this decay is not
saturated by any two-body intermediate state. In this work, we analyze the
multi-body weak decays of doubly heavy baryons , ,
, , and , in particular the
three-body nonleptonic decays and four-body semileptonic decays. We classify
various decay modes according to the quark-level transitions and present an
estimate of the typical branching fractions for a few golden decay channels.
Decay amplitudes are then parametrized in terms of a few SU(3) irreducible
amplitudes. With these amplitudes, we find a number of relations for decay
widths, which can be examined in future.Comment: 47pages, 1figure. arXiv admin note: substantial text overlap with
arXiv:1707.0657
Light vector meson and heavy baryon strong interaction
We calculate the coupling constants between the light vector mesons and heavy
baryons within the framework of the light-cone QCD sum rule in the leading
order of heavy quark effective theory. Most resulting sum rules are stable with
the variations of the Borel parameter and the continuum threshold. The
extracted couplings will be useful in the study of the possible heavy baryon
molecular states
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