CDECK  ID>, HWUANT.

*CMZ :-        -27/07/99  13.33.03  by  Mike Seymour

*-- Author :    Ian Knowles

C-----------------------------------------------------------------------

      FUNCTION HWUANT(IPART)

C-----------------------------------------------------------------------

C     Returns the antiparticle of IPART; uses HERWIG numbering

C-----------------------------------------------------------------------

      INCLUDE 'HERWIG61.INC'

      INTEGER HWUANT,IPART,IPDG,IANTI,OLDERR

      CHARACTER*8 CDUM

      OLDERR=IERROR

      IPDG=IDPDG(IPART)

      IF (IPDG.EQ. 9.OR.IPDG.EQ.21.OR.IPDG.EQ.22.OR.IPDG.EQ.23.OR.

     &    IPDG.EQ.25.OR.IPDG.EQ.26.OR.IPDG.EQ.32.OR.IPDG.EQ.35.OR.

     &    IPDG.EQ.36.OR.IPDG.EQ.91.OR.IPDG.EQ.98.OR.IPDG.EQ.99.OR.

     &    IPDG.EQ.130.OR.IPDG.EQ.310.OR.

     &    IPDG.EQ.1000021.OR.IPDG.EQ.1000022.OR.IPDG.EQ.1000023.OR.

     &    IPDG.EQ.1000025.OR.IPDG.EQ.1000035.OR.IPDG.EQ.1000039.OR.

     &    (FLOAT(INT(RSPIN(IPART))).EQ.RSPIN(IPART).AND.

     &     MOD(IPDG/100,10).EQ.MOD(IPDG/10,10).AND.

     &     MOD(IPDG/10,10).NE.0)) THEN

C Self-conjugate boson

        IANTI=IPART

      ELSEIF(IPART.EQ.211.OR.IPART.EQ.212) THEN

C Fourth generation (anti-)quarks

        IANTI=IPART+6

      ELSEIF(IPART.EQ.217.OR.IPART.EQ.218) THEN

        IANTI=IPART-6

      ELSE

C Non-zero charge particle

        CALL HWUIDT(1,-IPDG,IANTI,CDUM)

      ENDIF

      IF (IANTI.EQ.20) WRITE(6,10) RNAME(IPART)

  10  FORMAT(1X,A8,' has no antiparticle'/)

      HWUANT=IANTI

      IERROR=OLDERR

      END