Joint seminar/Seminaire commun Lapth/Lapp

par Alexander Korchin (KIPT - Kharkov Institute of Physics and Technology), Zbigniew Was (Cracow - Institute of Nuclear Physics)

vendredi 24 nov. 2023, 14:30 → 15:30 Europe/Paris

Auditorium Vivargent (LAPTh)

Alexander Korchin: 

Electron-positron, quark-antiquark and photon-photon production of tau-lepton pairs: spin effects induced by anomalous magnetic and electric dipole moments of tau lepton

Abstract: Anomalous contributions to the magnetic and electric dipole moments of the tau lepton have brought renewed interest in the development of new CP violating signatures in tau-pair production at Belle II, and at higher energies of the LHC and the Future Circular Collider.  We discuss spin correlations in the tau- tau+ pair produced in e- e+, q qbar -> tau- tau+ and gamma gamma -> tau- tau+  processes. Effects of anomalous dipole moments are introduced on top of precision simulations of these processes in the Standard Model (SM). The tau decays are simulated along with radiative corrections, in particular, electroweak box contributions of WW and ZZ exchange diagrams are taken into account. 

 

Zbigniew Was: 

New physics event re-weighting - general conditions

Abstract: Usually new physics effects, such as of dark photons, anomalous magnetic/electric dipole moments are expected to be at the edge of observability. That is why, for their predictions, simultaneous control of Standard Model predictions of sufficient precision is essential. I will comment the two classes of solutions, when internal information from the main Monte Carlo of Standard Model predictions is used or if information stored in event record is used only. Advantages, disadvantages and  practical difficulties for the users will be adressed.