Love is both physical and psychological. It is both biological and a conscious emotion. The study of love, as with much of Neuroscience, crosses boundaries.
Here’s My blog post on BrainFacts for valentine’s day. It’s largely an introduction to Lucy Brown and Helen Fischer’s website, AnatomyOfLove.com plus Q-and-A with Lucy. (Hit “continue reading” for Billie Hiliday’s rendition). 

Billie Holiday singing “What is this thing called love?” Cole Porter, 1929