الوصف:
There is new experimental evidence which may be interpreted as a small departure from quark-lepton universality. We propose to understand this as the result of a hierarchy of mass scales in analogy to m u, m d << L QCD for strong isospin. We show <img id="_x0000_i1026" src="../../img/revistas/bjp/v34n1a/a08img01.gif" align=absbottom>< <img id="_x0000_i1027" src="../../img/revistas/bjp/v34n1a/a08img02.gif" align=absbottom>< <img id="_x0000_i1028" src="../../img/revistas/bjp/v34n1a/a08img03.gif" align=absbottom>< <img id="_x0000_i1029" src="../../img/revistas/bjp/v34n1a/a08img04.gif" align=absbottom>in principle, but all are still approximately equal. New physics is predicted at the TeV scale.