Probing flavor changing top-charm-scalar interactions in $e^{+}{e}^{-}$ collisions

Abstract

Due to the very large mass of the top-quark, probing the flavor changing top-charm-scalar vertex is clearly very important. Fortunately the largeness of $m_t$ endows a unique signature to the resulting reaction i.e., $e^{+}{e}^{-}\to t\bar{c}(\bar{t}c)$ 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.

Comments: 10 pages, 3 figures, uuencoded-gzip-postscript file, figures are included