Agradecimentos: Work partially supported by INFN, MURST and CNR (Italy), by CNPq (Brazil), and by the I.N.R. (Kiev, Ukraine). The authors thank T.V. Obikhod, B.N. Zakhariev and particularli A.K. Zaichenko for their scientific collaboration; and M. Baldo, G. Giardina, A. Italiano, V.L. Lyuboshitz, G.D. Maccarrone, E.C. de Oliveira, R. Pucci, F. Raciti, M. Sambataro, S. Sambataro, C. Spitaleri for useful discussions. They are also grateful to C.L. Leavens for having contacted them and for subsequent discussions by E-mail. Ver menos

Abstract: In a recent review paper [Phys. Reports 214(1992)339] we proposed new definitions for the sub-barrier tunnelling and reflection times, which seem to be meaningful and acceptable within convencional quantum mechanics. Aims of the present note are: (i) to show that our definition < TT > of the average transmission time results to constitute an improvement upon the ordinary dwell-time Dw formula; (ii) to propose new definitions also for the variances (or dispersions) DTT and DTR of the transmission and reflection times; (iii) to reply to some recent comments by C.R.Leavens [Solid State Commun. 85(1993115], which were uncorrectly based not on our own equations, but on different formulae (with integrations, in particular, running from 0 to oo [Leavens'] instead of running from -8o to 8 [ours]). We take advantage of such opportunity for confirmimg that our approach predicts the existence of the Hartman effect, an effect that in these days, at Cologne and at Berkeley, is receiving very interesting and intriguing experimental verifications Ver menos