Related papers: Optimal determination of New Physics couplings: A …
Measurements of angular correlations in nuclear beta decay are important tests of the Standard Model (SM). Among those, the so-called D correlation parameter occupies a particular place because it is odd under time reversal, and because the…
Polarization phenomena are essential for the understanding of elementary processes, and are typically large in the threshold region. The selection rules with respect to P-parity, angular momentum, isotopic spin and the Pauli principle allow…
Non-decoupling effects of heavy new particles cannot be described by the standard effective field theory with finite truncation of higher dimensional operators. We propose a new effective field theory in which non-decoupling quantum effects…
The recent observation of entanglement between top and anti-top quarks at the LHC opens the way to interpreting collider data with quantum information tools. In this work we investigate the relevance of quantum observables in searches of…
In the companion paper it was shown that there are six observables in $gg\to t \bar t \to (b \bar b c) (\bar b \ell \bar \nu)$ that can be used to reveal the presence of new physics (NP) in $t \to b \bar b c$. In the present paper we…
In this report I surveyed physics potential of the gamma-gamma option of a Linear e+e- Collider with the following questions in mind: What new discovery can be expected at a gamma-gamma collider in addition to what will be learned at its…
We present the results of generalized measurements of optical polarization designed to provide one of three or four distinct outcomes. This has allowed us to discriminate between nonorthogonal polarization states with an error probability…
We study polarization and spin correlation effects in the MSSM and in extended supersymmetric models at an e^+e^- linear collider with polarized beams. The production of light neutralinos e^+ e^- --> \tilde\chi^0_1 \tilde\chi^0_2 and the…
An optimal-observable analysis of the angular and energy distributions of the leptons and bottom quarks in the process e+e- --> tt-bar --> l^{+-}/b(b-bar)... has been performed in order to measure the most general top-quark couplings to…
Many new physics models predict sizable modifications to the SM Zbb couplings, while the corresponding measurements at LEP and SLC exhibit some discrepancy with the SM predictions. After updating the current results on the Zbb coupling…
The proposed $e^+e^-$ collider offers an ideal environment for precise estimation of Higgs boson properties which are of utmost importance to validate the Standard Model of particle physics. We investigate $hVV$ couplings, where $V\in…
Extra neutral gauge bosons suggested by models beyond the standard model can indirectly show up in $e^{+} e^{-}$ collisions through off-resonance deviations of various physical observables from the corresponding standard model values. We…
We study the determination of the symmetry that stabilizes a dark matter (DM) candidate produced at colliders. Our question is motivated per se, and by several alternative symmetries that appear in models that provide a DM particle. To this…
If new particles are discovered, it will be important to determine if they are the supersymmetric partners of standard model bosons and fermions. Supersymmetry predicts relations among the couplings and masses of these particles. We discuss…
Polarized $\Lambda_b \to \Lambda \gamma$ decays at the Z pole are shown to be well suited for probing a large variety of New Physics effects. A new observable is proposed, the angular asymmetry between the $\Lambda_b$ spin and photon…
One of the main endeavors at future high-energy colliders is the search for the Higgs boson(s) and, once found, the probe of the fundamental properties. In particular, the charge conjugation and parity (CP) quantum numbers have to be…
In absence of the Standard Model Higgs boson the interaction among the gauge bosons becomes strong at high energies and influences the couplings between them. Each trilinear and quartic gauge boson vertex is characterised by a set of…
Motivated by the difference between SLD's recent measurement of ALR and the corresponding LEP results, we explore which kinds of new particles can (1) contribute dominantly to new physics through oblique corrections, (2) produce negative…
We perform a model-independent global fit to all germane and updated $b \to s \ell \ell$ ($\ell=e,\,\mu$) data assuming new physics couplings to be complex. Under the approximation that new physics universally affects muon and electron…
Recent studies have shown that quantitative concepts from quantum information theory can play a role in analysing collider physics, including elucidating new physics. In this paper, we study various QI measures including magic, trace…