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

The search for new physics in $B \to K \ell^+\ell^-$ and $B \to K \nu\bar{\nu}$ using precise lattice QCD form factors

Aug 8, 2022, 4:50 PM
CP1-HSZ/1.002 (CP1-HSZ) - HS6 (CP1-HSZ)

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


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


William Parrott (University of Glasgow)


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 $B \to K \nu\bar{\nu}$ and discuss the significance of the tensions that arise.

Primary author

William Parrott (University of Glasgow)


Prof. Christine Davies (University of Glasgow) Dr Chris Bouchard (University of Glasgow)

Presentation materials