Jakub Ryżka (AGH): New searching approaches of CP violation effects in the Ξ$^+_c$ → pK$^−$π$^+$ decays in the LHCb experiment

Friday 26 May 2023, 10:15 → 11:00 Europe/Warsaw

Abstract:

One the main goal of High Energy Physics is a search for physics beyond the Standard Model (called new physics). The measurements of CP-violating asymmetries in particle decays containing a charm quark create perfect environment for the new physics searches since the background from the Standard Model is small as the expected value of CP violation is about a few per milles or less. The LHCb experiment tests the Standard Model predictions in very precise measurements of CP violation using very sophisicated research methods. Recently, the LHCb experiment has measured the direct CP asymmetries separately for the two decay modes: D^0 to K^- K^+ and D^0 to pi^- pi^+. These results will be presented during the seminar as them constitute the first evidence for CP violation in a specific charm hadron decay. The compatibility with the hypothesis of CP symmetry is 3.8 standard deviations. The new searches for CP asymmetries in three-body charm baryon decays will be also presented. Three-body processes are always more rare than the two-body processes, but they can provide much more information about CP violation. Many observables are available to measure in multi-body processes. In contrast, in two-body processes, only one variable is measured (global result of CP violation). So far, in charm baryons the level of 2.7 standard deviations of agreement with CP symmetry was measured. The new approaches will be discussed during seminar as well as their tests obtaining in control decays.

Important: This seminar is held in building D-11 room 104. 

26052023-JakubRyzka-CPinLHCb.pdf