Amplitude analysis of B → K*μμ at LHCb
Student: Mr. Andrea Mauri
Motivated by the recent anomalous results on the angular distributions of the decay B → K*μμ and in the ratio of branching fraction in b → sll transitions, a novel amplitude analysis approach that enables the direct determination of observables that encode potential non-equal couplings of muons and electrons is being performed at LHCb. Relying on the state of the art parametrisation of the non-local contributions, this analysis will provide the most precise extraction of the B → K*μμ angular observable using Run-I and part of Run-II dataset.
Angular analysis of the decay B → K*ee at LHCb
Student: Ms. Federica Lionetto
A counting experiment analysis of the key channel B → Kee with the LHCb Run-I dataset has been performed in conjunction with the student. This measurement is of great importance to confirm the anomalous behaviour in the P5′ observable, but also to probe the hypothesis that this could be related to lepton flavour universality violation in b → sll transitions. These results are the first step towards a large physics programme to be pursuit in LHCb.
Search for the decay B → Kππee at LHCb
Student: Jonas Eschle
Lepton flavour universality tests in B → Kππll decays are sensitive to different combinations of couplings with respect to RK and provide additional constraints to NP effects. The first step towards this physics programme is to establish its signal with the LHCb spectrometer. The student has been educated on features related to multivariate algorithms and designed the selection and fit model for this measurement. These studies are the instrumental for the publication planned for this year.
Feasibility studies of the decay B → K*ττ at LHCb
Student: Alexander Dätwyler
Sensitivity studies of the unobserved decay channel B → K*ττ, in which taus are reconstructed from the chain πππντ have been performed. This mode probes the same observables of other b → sll transitions, but in the presence of NP, its effects should be enhanced for this final state. This analysis was based on the LHCb run-i dataset, and used to extrapolate for the projected luminosities in Run-II and LHCb upgrade. These results indicate that is unlikely that LHCb can observed this mode in a near future with the current setup.