We study the processes W L W L → tt and W L Z L → tb (tb) at future lepton colliders as probes of the couplings of the top quark to resonances at the TeV scale. We consider the cases in which the dominant low energy feature of a strongly interacting electroweak symmetry breaking sector is either a scalar or a vector resonance with mass near 1 TeV.We find that future lepton colliders with high energy and high luminosity have great potential to sensitively probe these physics scenarios. In particular, at a 1.5 TeV linear collider with an integrated luminosity of 200 fb −1 , we expect about 120 events for either a scalar or a vector to decay to tt, tb. Their leading partial decay widths, which characterize the coupling strengths, can be statistically determined to about 10% level.
For the next-generation, burning tokarnak plasmas such as 17ER, diagnostic neutral beams and beam spectroscopy will continue to be used to determine a variety of plasma parameters such as ion temperature, rotation, fluctuations, impurity content, current density profile, and confined alpha particle density and energy distribution.Present-day low-current, long-pulse beam technology will be unable to provide the required signal intensities because of higher beam attenuation and background bremsstrahlung radiation in these larger, higher-density plasmas. To address this problcm, we are developing a short-pulse, intense diagnostic neutral beam. Protons or dcuterons are accelerated using inagnctic-insulated ion-diode technology, and neutralized in a transient gas CC(I.A prototype 25-kA, 100-kV, I-ps accelerator is under construction at Los Alamos. Initial experiments will focus on LW7t-related issues of beam energy distribution, current density, pulse Icngth, divergence, propagation, impurity content, reproducibility, and maintenance.-1-
A spectroscopic diagnostic for measurement of slowing-down alpha particles is under development and will be implemented for D–T operation of the Tokamak Fusion Test Reactor. The visible 468.6 nm He+ line (n=3–4) is excited by charge exchange recombination of alphas with a heating neutral beam (55 keV/amu), and the distortion of the line profile caused by alphas with energies up to 0.5–1.0 MeV is observed. Expected intensities are 0.1%–10% of the bremsstrahlung background for D–T discharges with Q=0.2–1.0. Because the signal is small, a high-throughput optical system is needed to achieve the desired signal-to-noise ratio of 10–100. Vertical and horizontal arrays of sightlines with five spatial channels will be used. Initially, two spatial channels will be coupled via fiber optics to an f/3.8 spectrometer equipped with a low-noise charge coupled device detector, with expansion to 5–10 spatial channels planned for D–T operation.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.