The 39th International Symposium on Lattice Field Theory (Lattice 2022)

Aug 8 – 13, 2022
Hörsaalzentrum Poppelsdorf
Europe/Berlin timezone

Inclusive semileptonic $B$-decays from lattice QCD

Aug 12, 2022, 3:10 PM
20m
CP1-HSZ/1st-1.002 - HS6 (CP1-HSZ)

CP1-HSZ/1st-1.002 - HS6

CP1-HSZ

50
Oral Presentation Weak Decays and Matrix Elements

Speaker

Antonio Smecca (University of Turin)

Description

Among the many anomalies and tensions in flavour physics, one of the most persistent ones is the $V_{cb}$ puzzle, which is a difference of about $2.7 \sigma$ between the inclusive and exclusive estimate of the CKM matrix element $V_{cb}$. In order to understand the origin of this tension from first principles, one needs calculations obtained using lattice QCD.
Over the years, lattice QCD has been extremely successful in calculating physical quantities needed for the exclusive determination of $V_{cb}$ to a high level of precision.
It is only until recently that new methods have been proposed for computing inclusive decay rates of semileptonic B-decays using lattice QCD. These new methods rely on the extraction of the hadronic spectral density from Euclidean correlators computed on the lattice.
In this talk, one of these new methods will be discussed together with the presentation of the first results of the inclusive decay rate and related observables. We use one of the gauge ensembles provided by the ETM collaboration with an unphysical pion mass and unphysically light $b$-quark. The results obtained are also compared with the analytic predictions of the Operator Product Expansion (OPE) and provide a first systematic study of the quark-hadron duality.

Primary author

Antonio Smecca (University of Turin)

Co-authors

Prof. Paolo Gambino (University of Turin) Prof. Shoji Hashimoto (KEK, SOKENDAI) Mr Sandro Mächler (University of Turin, University of Zurich) Prof. Marco Panero (University of Turin) Dr Francesco Sanfilippo (INFN, Sezione Roma Tre) Prof. Silvano Simula (INFN, Sezione Roma Tre) Prof. Nazario Tantalo (University of Rome Tor Vergata)