Unique Mass Texture for Quarks and Leptons

Texture specific quark mass matrices which are hermitian and hierarchical are examined in detail . In the case of texture 6 zeros matrices, out of sixteen possibilities examined by us, none is able to fit the low energy data (LED). Similarly none of the 32 texture 5 zeros mass matrices considered is able to reproduce LED. In particular, the latest data from LEP regarding $|V_{ub}|/|V_{cb}|(=0.093\pm0.016)$ rules out all of them. In the texture 4 zeros case, we find that there is a unique texture structure for $U$ and $D$ mass matrices which is able to fit the data. When a similar texture structure is assumed for neutrinos, we are able to reproduce a mixing matrix which can accomodate Solar Neutrino Problem, Atmospheric Neutrino Problem and the oscillations observed at LSND simultaneously.