Single top-quark t-channel production is exploited for studies of top quark properties. The analyses include the measurement of the CKM matrix element, |Vtb|, search for anomalous couplings of the ...top quark using a Bayesian neural network analysis, measurement of single top-quark polarization which directly confirms the V-A nature of the tWb production vertex, and the measurement of W-helicity fractions in the phase space sampled by a selection optimized for t-channel single top-quark production, orthogonal to the tt‾ final states used in traditional measurements of these properties. All measurements are found to be consistent with the standard model predictions.
ABSTRACT
Distance versus dispersion measure relations are constructed for Galactic radio pulsars in small solid angle intervals. The calculations are based on some basic criteria, as well as using ...the independent distance measurements of well examined pulsars for the first Galactic quadrant, including Galactic central directions. Values of average free electron density for these regions are derived from the fits to distance versus dispersion measure relations and checked for consistency and smoothness. The effects of plasma in the Galactic arms and within the central parts of the Galactic bulge region are also compared and discussed. Our adopted distances for the radio pulsars are compared with the ones given in some other models. Some basic results on distributions of the radio pulsars and the plasma are presented.
We propose in this White Paper a concept for a space experiment using cold atoms to search for ultra-light dark matter, and to detect gravitational waves in the frequency range between the most ...sensitive ranges of LISA and the terrestrial LIGO/Virgo/KAGRA/INDIGO experiments. This interdisciplinary experiment, called Atomic Experiment for Dark Matter and Gravity Exploration (AEDGE), will also complement other planned searches for dark matter, and exploit synergies with other gravitational wave detectors. We give examples of the extended range of sensitivity to ultra-light dark matter offered by AEDGE, and how its gravitational-wave measurements could explore the assembly of super-massive black holes, first-order phase transitions in the early universe and cosmic strings. AEDGE will be based upon technologies now being developed for terrestrial experiments using cold atoms, and will benefit from the space experience obtained with, e.g., LISA and cold atom experiments in microgravity.
KCL-PH-TH/2019-65, CERN-TH-2019-126
We present the initial steps in the measurement of the forward-backward asymmetry (AFB) for μ+ μ− pairs produced via an intermediate Z/γ* at √s = 7 TeV in the CMS experiment. Our results are based on ...an integrated luminosity of 198 nb−1. The uncorrected forward-backward asymmetry is measured to be −0.50±0.40 in the mass range 40–70 GeV, and 0.14±0.11 in 70–110 GeV. The measured values are consistent with POWHEG + PYTHIA + full CMS simulation predictions of −0.03 and 0.01 in these two mass bins.
We present the initial steps in the measurement of the forward-backward asymmetry (A sub(FB)) for mu super(+) mu super(-) pairs produced via an intermediate Z/ gamma * at radicals = 7 TeV in the CMS ...experiment. Our results are based on an integrated luminosity of 198 nb super(-1). The uncorrected forward-backward asymmetry is measured to be -0.50+ or -0.40 in the mass range 40-70 GeV, and 0.14+ or -0.11 in 70-110 GeV. The measured values are consistent with POWHEG + PYTHIA + full CMS simulation predictions of -0.03 and 0.01 in these two mass bins.
We review the main software and computing challenges for the Monte Carlo physics event generators used by the LHC experiments, in view of the High-Luminosity LHC (HL-LHC) physics programme. This ...paper has been prepared by the HEP Software Foundation (HSF) Physics Event Generator Working Group as an input to the LHCC review of HL-LHC computing, which has started in May 2020.
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