Yes:

Love has no secrets from neurologists armed with an MRI brain scanner. What they have found contradicts the cynics: there is such a thing as everlasting love.

Researchers at Stony Brook University in New York have shown that the traditionally sorry path of sexual love – a downward spiral from lust to indifference over the space of a decade – is not an iron rule. Scanning the brains of people who have been together for 20 years, the scientists found that about one in 10 couples still display elements of “limerence”, the psychologists’ term for the obsessive behaviour of new lovers. They enjoy “intensive companionship and sexual liveliness” but without the anxieties and tensions of early love. They are generous, calm and deeply attached. The scientists call them swans (swans mate for life). This is good news for the 10%, if not for the remaining 90% gripped by marital fatigue.

What's more, these researchers believe they have discovered the biological basis for "love".