## Open LHCb Workshop on semileptonic exclusive $brightarrow c$ decays

### 12 April @ 14:00 - 14 April @ 18:30

The semileptonic decays of heavy hadrons are a rich source of observables sensitive to SM and NP paramaters. Despite the efforts from both experimental and theoretical sides, the measurements of the CKM parameter $|V_{cb}|$ from inclusive and exclsuive decays, remain in significant tension. Moreover, the measurements of the ratios $R=BF(Brightarrow D^{(*)}taunu_{tau})/ BF(Brightarrow D^{(*)}ellnu_{ell})$ have gained in the last decade a lot of interests because of the intriguing discrepancies with their precise SM expectations. Even if the tension with the SM seems reduced with the accumulation of more measurements, more precise measurements and solid SM predictions would be welcome. If confirmed, the discrepancy would be a clear sign of violation of Lepton Universality (LU).The main goal of the workshop is to enlarge the potential of these measurements at LHCb, with a critical comparison with the results from B-Factories and prospects from Belle II.  The measurements of $|V_{cb}|$ and the predictions of the ratios R from exclusive $bto c$ decays, require crucial input from non perturbative calculations of the Form Factors. New observables, accessibile from detailed studies of final state angular distributions, are very sensitive to NP models and can also constrain the shape of the Form Factors.Another topic that will be discussed is related to common systematic uncertainties that affect measurements both at LHCb and B-Factories. For example the production of excited charm-hadrons in semileptonic decays, that is a source of physical background. Moreover there are common tools that could be shared between the various experiments to speed up the analysis process and for better understanding of common systematics.Finally, these analyses require improvements  in external inputs from both theory and experiment. Some of these inputs would need dedicated measurements from other facilities, as BESIII. A coordination accross experiments would be beneficial for many analyses.All of this will be discussed during the first two days of the workshop between the LHCb community, the theorists of flavour physics and the experimentalists from other heavy flavour facilities. Friday morning will be dedicated to internal discussions of the LHCb collaboration.The Workshop will be held in the “Bruno Touschek” Auditorium (Bldg. 36). Participants will access from the LNF secondary entrance in Via E. Fermi, 60 (see map).

### Details

Start:
12 April @ 14:00
End:
14 April @ 18:30
Event Category:
Target:
Website:
https://agenda.infn.it/event/34419/

## Venue

Auditorium B. Touschek
Via Enrico Fermi, 54
Frascati, Roma 00044 Italia