C********************************************************************* 
 
      SUBROUTINE LUPTDI(KFL,PX,PY) 
 
C...Purpose: to generate transverse momentum according to a Gaussian. 
      COMMON/LUDAT1/MSTU(200),PARU(200),MSTJ(200),PARJ(200) 
      SAVE /LUDAT1/ 
 
C...Generate p_T and azimuthal angle, gives p_x and p_y. 
      KFLA=IABS(KFL) 
      PT=PARJ(21)*SQRT(-LOG(MAX(1E-10,RLU(0)))) 
      IF(PARJ(23).GT.RLU(0)) PT=PARJ(24)*PT 
      IF(MSTJ(91).EQ.1) PT=PARJ(22)*PT 
      IF(KFLA.EQ.0.AND.MSTJ(13).LE.0) PT=0. 
      PHI=PARU(2)*RLU(0) 
      PX=PT*COS(PHI) 
      PY=PT*SIN(PHI) 
 
      RETURN 
      END