Abstract:
We report our recent progress on the lattice calculation of the
hadronic light-by-light (HLbL) contribution muon $g-2$. Previously, we
have completed the connected diagrams and the leading disconnected
diagrams calculation on the $48^3 \times 96$ lattice with physical
pion mass and 5.5 fm box size. The result is $a_\mu = 5.35(1.35)\times
10^{-10}$, where the error is statistical only. We expected sizable
finite volume errors, mostly from the QED part of the calculation. To
address this issue, we developed a strategy which allows the QED part
of the HLbL diagram being evaluated separately in the infinite volume
with continuum propagators. We have obtained some preliminary results
on RBC/UKQCD's recently generated coarse $48^3\times 64$ lattice with
physical pion mass and 9.6 fm box size.