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

The search for new physics in B→Kℓ+ℓ− and B→Kνν¯ using precise lattice QCD form factors

8 Aug 2022, 16:50

20m

CP1-HSZ/1.002 (CP1-HSZ) - HS6 (CP1-HSZ)

Oral Presentation Weak Decays and Matrix Elements Weak Decays and Matrix Elements

Speaker

William Parrott (University of Glasgow)

Description

We present HPQCD's improved scalar, vector and tensor form factors for $B\to K$ semileptonic decays, using the heavy-HISQ formalism for more accurate normalisation of the weak currents. Working with masses close to the physical $b$ on the finest ensemble and including three ensembles with physical light quarks, we cover the full physical $q^2$ range with good precision. Our uncertainties at $q^2=0$ are a factor of three better than earlier work.

We compare Standard Model observables using our form factors to experimental measurements for the rare flavour changing neutral current processes $B\to K{\ell }^{+}{\ell }^{-}$ and $B\to K\nu \overline{\nu }$ and discuss the significance of the tensions that arise.

Presentation materials

WillParrottLAT2022.pdf