title: Tetraquark mesons in large-N quantum chromodynamics.
abstract: It is argued that exotic mesons consisting of two quarks and two antiquarks are not ruled out in quantum chromodynamics with a large number N of colors, as generally thought. Tetraquarks of one class are typically long-lived, with decay rates proportional to 1/N.
authors.affiliation: Department of Physics, Theory Group, University of Texas Austin, Texas 78712, USA. weinberg@physics.utexas.edu
authors.forename: Steven
authors.initials: S
authors.lastname: Weinberg