Heavy-quark exotics

Abstract

The heavy quarks $c$ and $b$ stabilize exotic meson $(qq\bar{q}\bar{q})$ and baryon $(qqqq\bar{q})$ states. We discuss work with M. Karliner on molecules containing $c\bar{c}$ and $b\bar{b}$; the first doubly charmed baryon; isospin splittings; ${\Xi }_{cc}^{+}=ccd$ and ${\Omega }_{cc}=ccs$ masses; lifetimes; tetraquarks stable under strong and electromagnetic decay; excited ${\Omega }_c$ states; and P-wave excitation energies.

Comments: 9 pages, 4 figures