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 zero matrices, out of sixteen possibilities examined by us, none is able to fit the low energy data (LED), for example, |V_us|=0.2196±0.0023, |V_cb|=0.0395±0.0017, |V_ub/V_cb|=0.08±0.02, and |V_td| lies in the range 0.004–0.014 (PDG). Similarly none of the 32 texture 5 zero mass matrices considered is able to reproduce the LED. In particular, the latest data from CERN LEP regarding |V_ub/V_cb|=(0.093±0.016) rules out all of them. In the texture 4 zero case, we find that there is a unique texture structure for U and D mass matrices which is able to fit the data.