What is the name of this plant with small, 5-leaved divided pink blooms?
It looks like a Red Campion, which is native to northern and central Europe.



It would be nice to see a close-up of the calyx (which is usually striped) and the leaves to be sure; it may be a cross between a White and Red Campion. 

There are many members of the genus, and many look alike. Your close-up is of a male flower (anthers only). The plants are male or female.