Challenges in Semileptonic B Decays

Session

Heavy to heavy exclusive

23 Sept 2024, 14:00

26. New developments in B -> D(*) from lattice QCD

Alejandro Marino Vaquero Avilés-Casco (Universidad de Zaragoza)

23/09/2024, 14:00

27. FF Truncation and Model selection in |Vxb| extractions

Florian Urs Bernlochner (University of Bonn (DE))

23/09/2024, 14:30

8. Determination of Vcb from Exclusive Decays

Stefan Schacht (University of Manchester)

23/09/2024, 16:00

We present a determination of Vcb taking into account the most recent data on exclusive decays as well as form factor calculations from lattice QCD. We employ unitarity constraints within the Boyd-Grinstein-Lebed (BGL) parametrization and carefully study their impact on the results. Furthermore, we give updated Standard Model predictions for the lepton-flavor non-universality observables R(D(*)).

11. Model-independent fits to experimental and lattice data for $B\to D^\ast \ell\bar\nu$ (and other) exclusive decays

Andreas Juttner (CERN)

23/09/2024, 16:30

We present an analysis of the exclusive semileptonic decay $B\to D^\ast \ell\bar\nu$ based on the Belle and Belle II data made public in 2023 and considering also a new combination of both data sets by HFLAV, combined with recent lattice-QCD calculations of the hadronic transition form factors by FNAL/MILC, HPQCD and JLQCD. The analysis is based on the form-factor parameterisation by...

15. $B_{(s)} \to D_ {(s)}^{(*)}$ form factors at ${\cal O}(1/m_c^2)$

Nico Gubernari (University of Cambridge)

23/09/2024, 17:00

We perform a fit of the Isgur-Wise function including ${\cal O}(1/m_c^2)$ corrections to the available theoretical and experimental constraints. We include the tensor form factors and the corresponding unitarity bounds for the first time in this framework. We discuss the compatibility between the different constraints. We also compare our results with those of other methods. We present our SM...

28. LHCb/Belle II joint measurement of b-> c l nu Wilson Coefficients

Biljana Mitreska (Technische Universitaet Dortmund (DE))

24/09/2024, 09:00

29. Measurement of the B -> D*lnu form factor at Belle

Markus Tobias Prim (University of Bonn (DE))

24/09/2024, 09:30

6. B->D(*)lnu at BaBar and Lambda_b->Lambda_ctaunu at LHCb

Biplab Dey (Eotvos U.)

24/09/2024, 10:30

I will present two sets of results:
1/ legacy BaBar B->D()lnu with l=e/mu, angular analyses. This will cover https://arxiv.org/abs/2311.15071
and an update to: https://arxiv.org/abs/1903.10002, including all lattice B->D results in a joint BaBar+lattice fit.
2/ Lambda_b -> Lambda_c taunu, for 3-prong hadronic tau, at LHCb. The Run1 R(Lc) analysis is being updated to Run1+2. This includes...

17. Simultaneous analysis of $B \to D \ell \nu$ and $B\to D^{*} \ell \nu$ to improve the determination of $|V_{cb}|$.

Michele Mantovano (University and INFN Trieste)

24/09/2024, 11:00

We propose a simultaneous analysis of $B \to D \ell \nu$ and $B\to D^{*} \ell \nu$ decays to measure model-independent observables for the determination of $|V_{cb}|$. The $B\to D^{*} \ell \nu$ decays is partially reconstructed, removing systematic uncertainty on $|V_{cb}|$ from the soft-pion reconstruction. By assuming equality of the semileptonic decay width of $B^0$ and $B^+$ mesons, we...

39. Discussion -- Vcb exclusive

Florian Urs Bernlochner (University of Bonn (DE)), Oliver Witzel (Universität Siegen)

24/09/2024, 11:30

4. A model-independent parameterization of semileptonic B decays with two final-state hadrons

Florian Herren (Fermilab)

24/09/2024, 13:30

Semileptonic $B$ decays involving multiple final-state hadrons play a crucial role as backgrounds to studies of lepton flavour universality or recent anomaly observed in $B \rightarrow K\nu\nu$. Furthermore, these poorly understood decays constitute sizeable signal components in measurements of inclusive $B \rightarrow X_{u/c} \ell\nu$ decays and the subsequent extraction of inclusive...

5. Improving our understanding of B -> D pi l nu and B -> pi pi l nu decays

Raynette Van Tonder (McGill University)

24/09/2024, 14:00

In this talk, we present studies of two semileptonic decays with two hadrons in the final state. First, we’ll discuss $B \rightarrow D \pi \ell \nu$ decays that not only constitute a sizeable background for $R(D^{(*)})$ determinations, but also comprise a largely unknown signal component for inclusive $B \rightarrow X_{c}\ell \nu$ decays. The dominant decay chain proceeds through resonant $B...

24. Combining R(D(*)) measurements at Belle II

Ilias Tsaklidis (University of Bonn)

24/09/2024, 14:30

The $R(D^{(*)})$ ratio is an excellent test of Lepton Flavor Universality, that promises to elucidate the nature of potential Beyond the Standard Model physical processes. In this talk, we present the latest $R(D^{(*)})$ measurements from the Belle II experiment. Additionally, we explore a likelihood based combination of different analyses relying on orthogonal selections, that goes beyond...

30. Recent LHCb results on R(D) and R(D*)

Gregory Max Ciezarek (CERN)

24/09/2024, 16:00

31. New results from LHCb on semitauonic decays” (in particular B -> D**taunu )

Guy Henri Maurice Wormser (Université Paris-Saclay (FR))

24/09/2024, 16:30

40. Discussion -- R(D(*)) and LFU in semitauonic B decays

Marcello Rotondo (INFN e Laboratori Nazionali di Frascati (IT)), Thomas Mannel

24/09/2024, 17:00

20. New physics searches with angular analyses of b-hadron decays

Lucia Grillo (University of Glasgow (GB))

25/09/2024, 09:00

Differential measurements of semileptonic b-hadron decays not only further our understanding of hadronic effects and CKM matrix elements, but are also powerful probes for effects beyond the Standard Model description. An overview of the angular measurements currently pursued at LHCb is presented, including expected New Physics sensitivities and prospects for future measurements.

18. Opportunities with Baryons @ LHCb

Anna Lupato (Università di Bergamo & INFN Padova)

25/09/2024, 09:30

Semileptonic b-baryons decays provide powerful probes for testing the Standard Model and for searching for New Physics effects. In this contribution, the LHCb semileptonic measurements with b-baryons will be presented: the status, the analyses ongoing and the prospect for future.