Particle sudoku

Sudoku is so 2005, but this logic puzzle still has plenty of fans. Invented in 1979 by an American, the puzzle really took off in Japan. In the years since, it has distracted aficionados daily, appearing in the pages of newspapers worldwide alongside the traditional crossword puzzle.

But have you played particle sudoku? To solve this puzzle, all you need to do is make sure that each row, column, and 4x4 sub-grid contains each of the 16 observed particles usually listed as the components of the Standard Model. Those are the six quarks: u, d, s, c, t, b; the six leptons: e, μ, τ, ν_e, ν_μ, ν_τ; and the four force carriers: γ, g, W, Z. There is only one solution to this puzzle, but be warned: Don't expect to solve this in five minutes. And don't let those pesky neutrinos confuse you!
David Harris