Related papers: Z-pole observables in an effective theory
A sizeable difference in the differential production cross section of top- compared to antitop-quark production, denoted charge asymmetry, has been observed at the Tevatron. The experimental results seem to exceed the theory predictions…
We describe CP violating observables in resonant $W^\pm$ and $W^\pm$ plus one jet production at the Tevatron. We present simple examples of CP violating effective operators, consistent with the symmetries of the Standard Model, which would…
The discrepancy between the measured and theoretical production cross section of $b$ quarks at the Tevatron can probably be explained by the recently proposed scenario of light gluinos of mass 12-16 GeV and light sbottoms of mass $2-5.5$…
The violation of Lam-Tung relation in the high-$p_T^{\ell\ell}$ region of the Drell-Yan process at the LHC presents a long-standing discrepancy with the standard model prediction at $\mathcal{O}(\alpha_s^3)$ accuracy. In this Letter, we…
The $P_5'$ anomaly uncovered by the LHCb experiment in $B \to K^*\mu\mu$ angular observables has motivated a possible $Z'$ boson that couples to left-handed $b \to s$ transitions, where a model would be gauged $L_\mu - L_\tau$ symmetry, but…
We revisit the impact of top partial compositeness on electroweak precision observables in the misaligned vacuum basis. We identify a new source for $S$ in the singlet mixing case, and for $S$-$T$ in the bi-doublet mixing, stemming from…
Recent experimental results on angular observables in the rare decay $B\to K^*\mu^+\mu^-$ show significant deviations from Standard Model predictions. We investigate the possibility that these deviations are due to new physics. Combining…
We make a comparison of the predicted effective weak mixing angle, the Z-on resonance asymmetries and the W-boson mass to the LEP and SLD data at their present status. We find that the predicted MSSM values for the effective weak mixing…
If there is Lorentz symmetry violation in the $t$ quark sector of the standard model, changes to particles' dispersion relations might allow for the existence of stable top-flavored hadrons. Observations of the survival of high-energy…
We study the sensitivity reach to probe the electroweak dipole operators associated with a top quark at a multi-TeV lepton collider. Studying the electroweak dipole operators is strongly motivated by precision physics. The operators exhibit…
We review the effective field theory approach to physics beyond the Standard Model using dimension-six operators. Topics include the choice of operator basis, electroweak boson pair production, precision electroweak physics (including…
The search for effective field theory deformations of the Standard Model (SM) is a major goal of particle physics that can benefit from a global approach in the framework of the Standard Model Effective Field Theory (SMEFT). For the first…
This note presents a combination of published and preliminary electroweak results from the four LEP collaborations and the SLD collaboration which were prepared for the 2001 summer conferences. Averages from Z resonance results are derived…
Electroweak dipole operators in the Standard Model Effective Field Theory (SMEFT) are important indirect probes of quantum effects of new physics beyond the Standard Model (SM), yet they remain poorly constrained by current experimental…
Parameterization of heavy effects beyond the Standard Model is available using higher-dimension operators of the effective field theory and their Wilson coefficients, where their values are not known. Experimental sensitivity to the Wilson…
We study the phenomenology of simplified $Z^\prime$ models with a global $U(2)^3$ flavour symmetry in the quark sector, broken solely by the Standard Model Yukawa couplings. This flavour symmetry, known as less-minimal flavour violation,…
One year of Z- and WW-Threshold running of TESLA can provide the possibility to measure electroweak precision observables to an extremely high accuracy. At the Z peak O(10^9) Z bosons and about 6 10^8 b quarks can be collected. We employ…
Due to its high mass top quarks decay before top-flavoured hadrons can be formed. This feature yields experimental access to the top quark polarization and production asymmetries. The large top quark sample moreover enables measurements of…
At the LHC, top quark pairs are dominantly produced from gluons, making it difficult to measure the top quark forward-backward asymmetry. To improve the asymmetry measurement, we study variables that can distinguish between top quarks…
We show that in e-e+ colliders at energies above the Z-peak, the process e-e+ to b b(bar) becomes very sensitive to the presence of residual New Physics (NP) effects described by the dim=6 SU(3)*SU(2)*U(1) gauge invariant operators O(qW),…