Speaker
Description
We present results of the first lattice QCD calculation of $B_c \rightarrow B_s$ and $B_c \rightarrow B_d$ vector matrix elements with 4-momentum transfer across the entire physical range. Form factors are then extracted and combined with CKM matrix elements to predict the decay rates for $B_c^+ \rightarrow B_s^0 \overline{l} \nu_l$ and $B_c^+ \rightarrow B^0 \overline{l} \nu_l$. Results are derived from correlation functions computed with HISQ for light, strange, and charm quark propagators, and NRQCD for the bottom quark propagator. The calculation of correlation functions employs MILC Collaboration ensembles over a range of three lattice spacings. These gauge field configurations include HISQ sea quark effects of flavours charm, strange, and equal-mass up and down. We use ensembles with physically light up and down quarks, as well as heavier values.
