Rewording Theoretical Predictions at Colliders with Vacuum Amplitudes.

We propose multiloop vacuum amplitudes in the loop-tree duality (LTD) as the optimal building blocks for efficiently assembling theoretical predictions at high-energy colliders. This hypothesis is strongly supported by the manifestly causal properties of the LTD representation of a vacuum amplitude. The vacuum amplitude in LTD, acting as a kernel, encodes all the final states contributing to a given scattering or decay process through residues in the on-shell energies of the internal propagators.

m_{b} at m_{H}: The Running Bottom Quark Mass and the Higgs Boson.

We present a new measurement of the bottom quark mass in the MS[over ¯] scheme at the renormalization scale of the Higgs boson mass from measurements of Higgs boson decay rates at the LHC: m_{b}(m_{H})=2.60_{-0.31}^{+0.

Open Loop Amplitudes and Causality to All Orders and Powers from the Loop-Tree Duality.

Multiloop scattering amplitudes describing the quantum fluctuations at high-energy scattering processes are the main bottleneck in perturbative quantum field theory. The loop-tree duality is a novel method aimed at overcoming this bottleneck by opening the loop amplitudes into trees and combining them at integrand level with the real-emission matrix elements. In this Letter, we generalize the loop-tree duality to all orders in the perturbative expansion by using the complex Lorentz-covariant prescription of the original one-loop formulation.

Compact multigluonic scattering amplitudes with heavy scalars and fermions.

Combining the Berends-Giele and on-shell recursion relations we obtain an extremely compact expression for the scattering amplitude of a complex massive scalar-antiscalar pair and an arbitrary number of positive helicity gluons. This is one of the basic building blocks for constructing other helicity configurations from recursion relations. We also show explicitly that the scattering amplitude of massive fermions to gluons, all with positive helicity, is proportional to the scalar one, confirming in this way the recently advocated SUSY-like Ward identities relating both amplitudes.

Perturbative generation of a strange-quark asymmetry in the nucleon.

We point out that perturbative evolution in QCD at three loops generates a strange-antistrange asymmetry s(x) - s(x) in the nucleon's sea just from the fact that the nucleon has nonvanishing up and down quark valence densities. The recently computed three-loop splitting functions allow for an estimate of this effect. We find that a fairly sizable asymmetry may be generated.