5,255 research outputs found
Glueball Production via Gluonic Penguin B Decays
We study glueball production in gluonic penguin decay ,
using the next-to-leading order gluonic penguin interaction and
effective couplings of a glueball to two perturbative gluons. Subsequent decays
of a scalar glueball are described by using techniques of effective chiral
Lagrangian to incorporate the interaction between a glueball and pseudoscalar
mesons. Mixing effects between the pure glueball with other mesons are
considered. Identifying the to be a scalar glueball, we find that
both the top and charm penguin to be important and obtain a sizable branching
ratio for of order 1.3\times 10^{-4}
(f/0.07\mbox{GeV}^{-1})^2, where the effective coupling strength is
estimated to be GeV using experimental data for the branching
ratio of based on chiral Lagrangian estimate. An
alternative perturbative QCD based estimation of is a factor of 20 larger,
which would imply a much enhanced branching ratio. Glueball production from
this rare semi-inclusive decay can be probed at the LHCb and Belle II to
narrow down the allowed parameter space. Similar branching ratio is expected
for the pseudoscalar glueball. We also briefly comment on the case of vector
and tensor glueballs.Comment: Latex 14 pages with 2 figures. Significant update from the older
version of arXiv:hep-ph/0612108. Version to appear in Eur. Phys. J.
DNA sequences classification and computation scheme based on the symmetry principle
The DNA sequences containing multifarious novel symmetrical structure frequently play crucial role in how genomes work. Here we present a new scheme for understanding the structural features and potential mathematical rules of symmetrical DNA sequences using a method containing stepwise classification and recursive computation. By defining the symmetry of DNA sequences, we classify all sequences and conclude a series of recursive equations for computing the quantity of all classes of sequences existing theoretically; moreover, the symmetries of the typical sequences at different levels are analyzed. The classification and quantitative relation demonstrate that DNA sequences have recursive and nested properties. The scheme may help us better discuss the formation and the growth mechanism of DNA sequences because it has a capability of educing the information about structure and quantity of longer sequences according to that of shorter sequences by some recursive rules. Our scheme may provide a new stepping stone to the theoretical characterization, as well as structural analysis, of DNA sequences
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