Gluon fragmentation represents the dominant source of high energy prompt
quarkonia at hadron colliders. Fragmentation approximations break down,
however, when a quarkonium's transverse momentum becomes comparable to its
mass. In this paper, we identify a large class of color-octet diagrams that
mediate quarkonia production at all energies and reduce to the dominant set of
gluon fragmentation graphs in the high $p_\perp$ limit. They contribute to
quarkonia differential cross sections at the same order as color-singlet
diagrams and bring theoretical predictions for Upsilon and Psi production at
the Tevatron into agreement with experimental measurements. Using recent CDF
data, we extract numerical values for bottomonia and charmonia color-octet
matrix elements which are consistent with NRQCD scaling rules. We also find
that quarkonia generated via the color-octet mechanism are strongly polarized
at low as well as high energies. Spin alignment measurements can thus test the
color-octet quarkonia production picture.Comment: 23 pages, harvmac, 11 uuencoded figure
The flavor changing neutral current processes K L → π 0 e + e − , B → X s e + e − and B → X s µ + µ − are studied within the minimal supersymmetric extension of the Standard Model. We first examine the rates for these decay modes in the MSSM with a universal soft supersymmetry breaking sector at a Grand Unification scale. We later relax the universality condition and investigate the FCNC transitions in a more general class of models with negligible flavor violation in squark mixing matrices. We find that the MSSM prediction for the kaon channel's branching fraction differs from its Standard Model value by at most 30% over the entire allowed parameter space. On the other hand, supersymmetric contributions could potentially enhance certain B → X s ℓ + ℓ − observables by more than 100% relative to Standard Model expectations. The impact of supersymmetry upon the B meson modes is strongly correlated with the MSSM value for the Wilson coefficient of the magnetic moment operator that mediates B → X s γ.
This paper analyzes task assignment for heterogeneous air vehicles using a guaranteed conflict-free assignment algorithm, the Consensus Based Bundle Algorithm (CBBA). We extend this recently proposed algorithm to handle two realistic multi-UAV operational complications. Our first extension accounts for obstacle regions in order to generate collision free paths for UAVs. Our second extension reduces task planner sensitivity to sensor measurement noise, and thereby minimizes churning behavior in flight paths. After integrating our enhanced CBBA module with a 3D visualization and interaction software tool, we simulate multiple aircraft servicing stationary and moving ground targets. Preliminary simulation results establish that consistent, conflict-free multi-UAV path assignments can be calculated on the order of a few seconds. The enhanced CBBA consequently demonstrates significant potential for real-time performance in stressing environments.
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