B meson spectroscopy

We study the B meson spectroscopy allowing the mixture of conventional P wave quark-antiquark states and four-quark components. A similar picture was used to describe the new D-J and D-sJ open-charm mesons. The four-quark components shift the masses of some positive parity B-sJ states below their corresponding isospin preserving two-meson threshold and therefore they are expected to be narrow. Electromagnetic decay widths are analyzed.