Yes yes is a good book... Dont know about Zen per se, but close....Get Elements of Poker. It's more than just that but the tilt control parts of it are where it shines brightest imo.
I've also read Poker Mindset and it's ok but very repetitive and rather boring.
Edit: You can see the ToC and read excerpts from Elements here: http://tommyangelo.com/table_of_contents.html