The performances of a silicon tungsten electromagnetic calorimeter for flavour physics has been studied. The study uses a fast simulation, with a geometry of the detector taken from ILD. This fast simulation is based on timing algorithm for the photon reconstruction which is planed to be presented in another talk at LCWS. When possible, a 1-C fit of the pi0 mass is used. The paradigm about...
Future Higgs Factories will offer a clean environment to study $e^{+}e^{-} \rightarrow q\bar{q}$ processes ($q = s, c, b, t$) at various centre-of-mass energies, from the Z-pole up to the TeV scale. In this contribution, we focus on the case of $e^{+}e^{-} \rightarrow s\bar{s}$ at $\sqrt{s} = 250$ GeV, using full simulation and reconstruction within the ILD detector concept to evaluate...
The coupling of the Higgs boson to first and second generation fermions has yet to be measured experimentally. There still could be very large deviations in these couplings, as the origin of flavor is completely unknown. Nevertheless, if Yukawa couplings are modified, especially for light generations, there are generically strong constraints from flavor-changing neutral currents (FCNCs). ...
Our work resolves a long-standing problem in particle physics: the inability for theory to agree with the spectrum of heavy-jet mass data, particularly at the Z-pole, leading to unreliable strong-coupling fits and exclusion of this high-quality experimental data. Our key theoretical improvements include high-precision large-log resummation in both the dijet and shoulder regions, a rigorous...
Measurements at electron-positron colliders can probe the scale evolution of quark masses predicted by the Standard Model in several ways. LEP and SLD extracted mb(mZ) from three jet rates in Z->bbbar decay. A future Z-pole run can improve the precision considerably, while a measurement of mb at higher scale is possible from e+e- -> bbbar production at 250 GeV and above. A very precise...
The production of heavy-quark jets is accompanied by gluon bremsstrahlung. This radiation is suppressed at small angles and is proportional to the heavy-quark mass, a phenomenon known as the dead cone effect. In this talk, we present this effect for charm and bottom quark initiated jets using data from Z-boson decays in momentum space in the e+e− annihilation. The observed suppression is...
ATLAS speakers committee to provide a speaker (the contribution is currently circulating in the collaboration)
The potential of a scan of the center-of-mass energy through the top quark pair production threshold is revisited with a detailed simulation of experimental and machine-related effects. The dominant theory limitations are extensively discussed as well.
The talk is based on the ECFA Higgs/top/EW study and the results presented in https://arxiv.org/pdf/2503.18713.
Due to travel budget...
Recent LHC results have demonstrated the possibility to demonstrate that in certain kinematic regions top quark pairs are produced in as an entangled two-qubit system. Spin correlation measurements in top quark pair production at a high-energy linear collider can study a highly entangled quark-anti-quark system in a cleaner and more inclusive fashion, while beam polarization allows for some...
We present updated constraints on the top-quark sector of the Standard Model Effective Field Theory using data from Tevatron, LEP, and the LHC. Our global fit yields bounds for Wilson coefficients across various two-fermion, four-quark, and two-quark two-lepton operators. We assess these current bounds in relation to the prospects of the high luminosity phase of the Large Hadron Collider and...
By 2045 the LHCb upgrade 2 and the Belle 2 programmes will have been completed. What remains to be done after that? How much can a linear collider contribute, and for what is a giga-Z run needed? This contribution is based on the work of the ESPPU PPG flavour working group and aims at putting the linear collider flavour programme in context.
Placeholder abstract, talk requested from ATLAS speakers committee by Marcel Vos
The LHC offers new opportunities to characterize the evolution of the
strong coupling constant into an unexplored energy regime and can
provide precise inputs to the world average for alpha_s(mZ).
Highlights of this program are presented.
