      function QALB_DE( QALB, QASM ) 

!-----------------------------------------------------------------      
      implicit real*8 ( a-h,o-z )
!-----------------------------------------------------------------      

      QALB_DE = ( 1.0D0 - QASM**2.0D0 ) * QALB /
     \     ( 1.0D0 - QALB * QASM**2.0D0 )

      return
      end 
