Semileptonic $B \to D^{(*)} l \nu$ decays are of great phenomenological interest. In fact, they allow to extract one of the fundamental SM parameters, i.e. $|V_{cb}|$, and to look for beyond the SM physics. To achieve this, theoretical predictions are confronted with experimental measurements from LHCb, Babar and Belle (II). Therefore, to improve the precision of $|V_{cb}|$ and to further constrain beyond the SM physics, very precise and accurate theoretical predictions are needed. However, improving these predictions is a difficult task due to the non-perturbative QCD effects that characterise these decays.
I will discuss the existing calculations for the hadronic matrix elements in $B \to D^{(*)} l \nu$ decays. The precision can be further improved by combining these calculations and by exploiting model-independent information from unitarity bounds and HQET. I will also present some puzzling aspects of the present theoretical calculations and assess their consistency with the current experimental data.
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https://uni-bonn.zoom-x.de/j/66253567797?pwd=R2MrNmNCQnl4K1hSejd6VnBEYXJ2QT09
Meeting ID: 662 5356 7797
Passcode: 599591
Saime Gürbüz, Maike Hansen, Tatjana Lenz