3,056 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.
Lyapunov conditions for differentiability of Markov chain expectations: The absolutely continuous case
We consider a family of Markov chains whose transition dynamics are affected by model parameters. Understanding the parametric dependence of (complex) performance measures of such Markov chains is often of significant interest. The derivatives of the performance measures w.r.t. the parameters play important roles, for example, in numerical optimization of the performance measures, and quantification of the uncertainties in the performance measures when there are uncertainties in the parameters from the statistical estimation procedures. In this paper, we establish conditions that guarantee the differentiability of various types of intractable performance measures---such as the stationary and random horizon discounted performance measures---of general state space Markov chains and provide probabilistic representations for the derivatives
Convection and Shear Flow in TC Development and Intensification
Award # N0001412WX2084
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
Perceived coach autonomy support and athlete burnout : the role of athletes’ experiential avoidance
Researchers have found that perceived coach autonomy support is negatively related to athlete burnout. However, whether offering such support would be helpful for all athletes or only athletes with certain characteristics is unknown. Following the notion of autonomous goal regulation suggested in self-determination theory, the authors propose that having autonomy support from coaches will be more strongly associated with a decrease in athlete burnout among athletes with lower experiential avoidance than among those with higher experiential avoidance. Experiential avoidance is a tendency to escape, avoid, or modify the frequency of uncomfortable experiences. A total of 141 collegiate student athletes completed surveys at two time points over three months. The results indicate that perceived coach autonomy support is negatively related to athlete burnout. Furthermore, the negative relationship between perceived coach autonomy support and decreased athlete burnout is stronger when experiential avoidance is low rather than high. When the three dimensions of burnout were analyzed individually (i.e., emotional and physical exhaustion, reduced sense of accomplishment and sport devaluation), only emotional and physical exhaustion and overall score were significant. The implications and applications of these results are discussed from an interactionist perspective
Gene functionality's influence on the second codon: A large-scale survey of second codon composition in three domains
AbstractThe second codon of a transcript, besides encoding for an amino acid, is now known to also have multiple molecular functions and is involved in translation efficiency and protein turn-over and maturation processing. These multiple purposes therefore make the selection constraints on this codon's composition more complex. To examine the biological significance of various permutations of the second codon, we conducted a systematic survey of second codon composition from 442 selected genomes across three domains. The amino acid bias of the second codon is associated with specific protein functions. The most common amino acids (S, A, K and T) are significantly avoided in Cell Envelope-related genes but preferred in Translation or Energy Metabolism-related genes, suggesting that the function of a gene product is a significant factor influencing the composition of the second codon
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
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