Probing flavor-changing top-charm-scalar interactions ine+e−collisions

Because of the very large mass of the top quark, probing the flavor-changing top-charm-scalar vertex is clearly very important. Fortunately the largeness of ${\mathit{m}}_{\mathit{t}}$ endows a unique signature to the resulting reaction, i.e., ${\mathit{e}}^{+}$ ${\mathit{e}}^{\mathrm{-}}$→tc¯(t¯c), that should be helpful in identification of such events. A two Higgs doublet model, without natural flavor conservation, is used to give an illustrative estimate for the rate for these reactions. © 1996 The American Physical Society.