Matt Bellamy -- I've Got A New Muse ... Guess Who She Looks Like?

Matt Bellamy finally put the moves on his Kate Hudson doppelganger, because he and the gorgeous "Blurred Lines" music video star Elle Evans are now definitely banging.

Sources close to the new couple tell us Bellamy and Evans officially became an item back in March and were practically inseparable at Coachella, doing what all new couples do ... making out and taking sappy photo booth pics.

We're told they were also handsy last week at the Burberry Fashion Show in L.A. -- but she hasn't met his son yet. As we previously reported, they first met back in February through mutual friends ... and things heated up shortly after that.

We ran into Elle Wednesday at The Ivy ... and she was super tight-lipped re: Matt -- although she kinda slipped up as she said goodbye.