2,582 research outputs found
Revisiting the -Meson Production at the Hadronic Colliders
The production of heavy-flavored hadron at the hadronic colliders provides a
challenging opportunity to test the validity of pQCD predictions. There are two
mechanisms for the hadroproduction, i.e. the gluon-gluon fusion
mechanism via the subprocess and the
extrinsic heavy quark mechanism via the subprocesses and , both of which shall have sizable
contributions in proper kinematic region. Different from the
fixed-flavor-number scheme (FFNS) previously adopted in the literature, we
study the hadroproduction under the general-mass
variable-flavor-number scheme (GM-VFNS), in which we can consistently deal with
the double counting problem from the above two mechanisms. Properties for the
hadroproduction are discussed. To be useful reference, a
comparative study of FFNS and GM-VFNS is presented. Both of which can provide
reasonable estimations for the hadroproduction. At the Tevatron,
the difference between these two schemes is small, however such difference is
obvious at the LHC. The forthcoming more precise data on LHC shall provide a
good chance to check which scheme is more appropriate to deal with the
-meson production and to further study the heavy quark components in
hadrons.Comment: 18 pages, 8 figures, 4 tables. To match the published version. To be
published in Eur.Phys.J.
B_c meson rare decays in the light-cone quark model
We investigate the rare decays
and in the framework of the
light-cone quark model (LCQM). The transition form factors are calculated in
the space-like region and then analytically continued to the time-like region
via exponential parametrization. The branching ratios and longitudinal lepton
polarization asymmetries (LPAs) for the two decays are given and compared with
each other. The results are helpful to investigating the structure of
meson and to testing the unitarity of CKM quark mixing matrix. All these
results can be tested in the future experiments at the LHC.Comment: 9 pages, 11 figures, version accepted for publication in EPJ
Convection and Shear Flow in TC Development and Intensification
Award # N0001412WX2084
Sample Path Large Deviations for Heavy-Tailed Lévy Processes and Random Walks
Let be a L\'evy process with regularly varying L\'evy measure . We
obtain sample-path large deviations of scaled processes and obtain a similar result for random walks. Our results yield
detailed asymptotic estimates in scenarios where multiple big jumps in the
increment are required to make a rare event happen. In addition, we investigate
connections with the classical large-deviations framework. In that setting, we
show that a weak large deviations principle (with logarithmic speed) holds, but
a full large-deviations principle does not hold
Perturbative QCD analysis of decays
We study the first observed charmless modes, the
decays, in perturbative QCD formalism. The obtained branching ratios
are larger than
from QCD factorization. The comparison of the predicted magnitudes and phases
of the different helicity amplitudes, and branching ratios with experimental
data can test the power counting rules, the evaluation of annihilation
contributions, and the mechanism of dynamical penguin enhancement in
perturbative QCD, respectively.Comment: 14 pages, 2 tables, brief disscussion on hard sacle added, version to
appear in PR
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