Hadron widths in mixed-phase matter

We derive classically an expression for a hadron width in a two-phase region of hadron gas and quark-gluon plasma (QGP). The presence of QGP gives hadrons larger widths than they would have in a pure hadron gas. We find that the $\phi$ width observed in a central Au+Au collision at $\sqrt{s}=200$ GeV/nucleon is a few MeV greater than the width in a pure hadron gas. The part of observed hadron widths due to QGP is approximately proportional to $(dN/dy)^{-1/3}$.