⟷ avg r: — px
Energy ~ σ·L: —
State: —
Drag a quark (red, green, blue): the strings get thicker as you pull it away (strong interaction) and quickly bring it back into the confinement region once released.
By www.andreamininin.net
Three bound quarks: close = free motion with thin strings; far = thick strings and restoring force. Release ? quick return.