Proton structure as seen by electrons versus muons

I will talk about the low-energy nucleon structure in the context of the well-known “proton radius puzzle”, i.e. the 7 standard deviation discrepancy in the proton charge radius extraction based on either hydrogen and muonic hydrogen Lamb shift. I will briefly review the calculations of the proton structure (finite-size and polarizability effects) using dispersive methods and chiral effective field theory. Various scenarios for the resolution of the puzzle will be considered.