d6/deb/pyct5m_8f_source.html

C*********************************************************************


C...PYCT5M

C...Auxiliary function for parametrization of CTEQ5M1.

C...Author: J. Pumplin 9/99.


      FUNCTION pyct5m(IFL,X,Q)


C...Double precision declaration.

      IMPLICIT DOUBLE PRECISION(a-h, o-z)

      IMPLICIT INTEGER(i-n)


      parameter(nex=8, nlf=2)

      dimension am(0:nex,0:nlf,-5:2)

      dimension alfvec(-5:2), qmavec(-5:2)

      dimension mexvec(-5:2), mlfvec(-5:2)

      dimension ut1vec(-5:2), ut2vec(-5:2)

      dimension af(0:nex)


      DATA mexvec( 2) / 8 /

      DATA mlfvec( 2) / 2 /

      DATA ut1vec( 2) /  0.5141718e+01 /

      DATA ut2vec( 2) / -0.1346944e+01 /

      DATA alfvec( 2) /  0.5260555e+00 /

      DATA qmavec( 2) /  0.0000000e+00 /

      DATA (am( 0,k, 2),k=0, 2)

     & /  0.4289071e+01, -0.2536870e+01, -0.1259948e+01 /

      DATA (am( 1,k, 2),k=0, 2)

     & /  0.9839410e+00,  0.4168426e-01, -0.5018952e-01 /

      DATA (am( 2,k, 2),k=0, 2)

     & / -0.1651961e+02,  0.9246261e+01,  0.5996400e+01 /

      DATA (am( 3,k, 2),k=0, 2)

     & / -0.2077936e+02,  0.9786469e+01,  0.7656465e+01 /

      DATA (am( 4,k, 2),k=0, 2)

     & /  0.3054926e+02,  0.1889536e+01,  0.1380541e+01 /

      DATA (am( 5,k, 2),k=0, 2)

     & /  0.3084695e+02, -0.1212303e+02, -0.1053551e+02 /

      DATA (am( 6,k, 2),k=0, 2)

     & / -0.1426778e+02,  0.6239537e+01,  0.5254819e+01 /

      DATA (am( 7,k, 2),k=0, 2)

     & / -0.1909811e+02,  0.3695678e+01,  0.5495729e+01 /

      DATA (am( 8,k, 2),k=0, 2)

     & /  0.1889751e-01,  0.5027193e-02,  0.6624896e-03 /


      DATA mexvec( 1) / 8 /

      DATA mlfvec( 1) / 2 /

      DATA ut1vec( 1) /  0.4138426e+01 /

      DATA ut2vec( 1) / -0.3221374e+01 /

      DATA alfvec( 1) /  0.4960962e+00 /

      DATA qmavec( 1) /  0.0000000e+00 /

      DATA (am( 0,k, 1),k=0, 2)

     & /  0.1332497e+01, -0.3703718e+00,  0.1288638e+00 /

      DATA (am( 1,k, 1),k=0, 2)

     & /  0.7544687e+00,  0.3255075e-01, -0.4706680e-01 /

      DATA (am( 2,k, 1),k=0, 2)

     & / -0.7638814e+00,  0.5008313e+00, -0.9237374e-01 /

      DATA (am( 3,k, 1),k=0, 2)

     & / -0.3689889e+00, -0.1055098e+01, -0.4645065e+00 /

      DATA (am( 4,k, 1),k=0, 2)

     & /  0.3991610e+02,  0.1979881e+01,  0.1775814e+01 /

      DATA (am( 5,k, 1),k=0, 2)

     & /  0.6201080e+01,  0.2046288e+01,  0.3804571e+00 /

      DATA (am( 6,k, 1),k=0, 2)

     & / -0.8027900e+00, -0.7011688e+00, -0.8049612e+00 /

      DATA (am( 7,k, 1),k=0, 2)

     & / -0.8631305e+01, -0.3981200e+01,  0.6970153e+00 /

      DATA (am( 8,k, 1),k=0, 2)

     & /  0.2371230e-01,  0.5372683e-02,  0.1118701e-02 /


      DATA mexvec( 0) / 8 /

      DATA mlfvec( 0) / 2 /

      DATA ut1vec( 0) / -0.1026789e+01 /

      DATA ut2vec( 0) / -0.9051707e+01 /

      DATA alfvec( 0) /  0.9462977e+00 /

      DATA qmavec( 0) /  0.0000000e+00 /

      DATA (am( 0,k, 0),k=0, 2)

     & /  0.1191990e+03, -0.8548739e+00, -0.1963040e+01 /

      DATA (am( 1,k, 0),k=0, 2)

     & / -0.9449972e+02,  0.1074771e+01,  0.2056055e+01 /

      DATA (am( 2,k, 0),k=0, 2)

     & /  0.3701064e+01, -0.1167947e-02,  0.1933573e+00 /

      DATA (am( 3,k, 0),k=0, 2)

     & /  0.1171345e+03, -0.1064540e+01, -0.1875312e+01 /

      DATA (am( 4,k, 0),k=0, 2)

     & / -0.1014453e+03, -0.5707427e+00,  0.4511242e-01 /

      DATA (am( 5,k, 0),k=0, 2)

     & /  0.6365168e+01,  0.1275354e+01, -0.4964081e+00 /

      DATA (am( 6,k, 0),k=0, 2)

     & / -0.3370693e+01, -0.1122020e+01,  0.5947751e-01 /

      DATA (am( 7,k, 0),k=0, 2)

     & / -0.5327270e+01, -0.9293556e+00,  0.6629940e+00 /

      DATA (am( 8,k, 0),k=0, 2)

     & /  0.2437513e-01,  0.1600939e-02,  0.6855336e-03 /


      DATA mexvec(-1) / 8 /

      DATA mlfvec(-1) / 2 /

      DATA ut1vec(-1) /  0.5243571e+01 /

      DATA ut2vec(-1) / -0.2870513e+01 /

      DATA alfvec(-1) /  0.6701448e+00 /

      DATA qmavec(-1) /  0.0000000e+00 /

      DATA (am( 0,k,-1),k=0, 2)

     & /  0.2428863e+02,  0.1907035e+01, -0.4606457e+00 /

      DATA (am( 1,k,-1),k=0, 2)

     & /  0.2006810e+01, -0.1265915e+00,  0.7153556e-02 /

      DATA (am( 2,k,-1),k=0, 2)

     & / -0.1884546e+02, -0.2339471e+01,  0.5740679e+01 /

      DATA (am( 3,k,-1),k=0, 2)

     & / -0.2527892e+02, -0.2044124e+01,  0.1280470e+02 /

      DATA (am( 4,k,-1),k=0, 2)

     & / -0.1013824e+03, -0.1594199e+01,  0.2216401e+00 /

      DATA (am( 5,k,-1),k=0, 2)

     & /  0.8070930e+02,  0.1792072e+01, -0.2164364e+02 /

      DATA (am( 6,k,-1),k=0, 2)

     & / -0.4641050e+02,  0.1977338e+00,  0.1273014e+02 /

      DATA (am( 7,k,-1),k=0, 2)

     & / -0.3910568e+02,  0.1719632e+01,  0.1086525e+02 /

      DATA (am( 8,k,-1),k=0, 2)

     & / -0.1185496e+01, -0.1905847e+00, -0.8744118e-03 /


      DATA mexvec(-2) / 7 /

      DATA mlfvec(-2) / 2 /

      DATA ut1vec(-2) /  0.4782210e+01 /

      DATA ut2vec(-2) / -0.1976856e+02 /

      DATA alfvec(-2) /  0.7558374e+00 /

      DATA qmavec(-2) /  0.0000000e+00 /

      DATA (am( 0,k,-2),k=0, 2)

     & / -0.6216935e+00,  0.2369963e+00, -0.7909949e-02 /

      DATA (am( 1,k,-2),k=0, 2)

     & /  0.1245440e+01, -0.1031510e+00,  0.4916523e-02 /

      DATA (am( 2,k,-2),k=0, 2)

     & / -0.7060824e+01, -0.3875283e-01,  0.1784981e+00 /

      DATA (am( 3,k,-2),k=0, 2)

     & / -0.7430595e+01,  0.1964572e+00, -0.1284999e+00 /

      DATA (am( 4,k,-2),k=0, 2)

     & / -0.6897810e+01,  0.2620543e+01,  0.8012553e-02 /

      DATA (am( 5,k,-2),k=0, 2)

     & /  0.1507713e+02,  0.2340307e-01,  0.2482535e+01 /

      DATA (am( 6,k,-2),k=0, 2)

     & / -0.1815341e+01, -0.1538698e+01, -0.2014208e+01 /

      DATA (am( 7,k,-2),k=0, 2)

     & / -0.2571932e+02,  0.2903941e+00, -0.2848206e+01 /


      DATA mexvec(-3) / 7 /

      DATA mlfvec(-3) / 2 /

      DATA ut1vec(-3) /  0.4518239e+01 /

      DATA ut2vec(-3) / -0.2690590e+01 /

      DATA alfvec(-3) /  0.6124079e+00 /

      DATA qmavec(-3) /  0.0000000e+00 /

      DATA (am( 0,k,-3),k=0, 2)

     & / -0.2734458e+01, -0.7245673e+00, -0.6351374e+00 /

      DATA (am( 1,k,-3),k=0, 2)

     & /  0.2927174e+01,  0.4822709e+00, -0.1088787e-01 /

      DATA (am( 2,k,-3),k=0, 2)

     & / -0.1771017e+02, -0.1416635e+01,  0.8467622e+01 /

      DATA (am( 3,k,-3),k=0, 2)

     & / -0.4972782e+02, -0.3348547e+01,  0.1767061e+02 /

      DATA (am( 4,k,-3),k=0, 2)

     & / -0.7102770e+01, -0.3205337e+01,  0.4101704e+00 /

      DATA (am( 5,k,-3),k=0, 2)

     & /  0.7169698e+02, -0.2205985e+01, -0.2463931e+02 /

      DATA (am( 6,k,-3),k=0, 2)

     & / -0.4090347e+02,  0.2103486e+01,  0.1416507e+02 /

      DATA (am( 7,k,-3),k=0, 2)

     & / -0.2952639e+02,  0.5376136e+01,  0.7825585e+01 /


      DATA mexvec(-4) / 7 /

      DATA mlfvec(-4) / 2 /

      DATA ut1vec(-4) /  0.2783230e+01 /

      DATA ut2vec(-4) / -0.1746328e+01 /

      DATA alfvec(-4) /  0.1115653e+01 /

      DATA qmavec(-4) /  0.1300000e+01 /

      DATA (am( 0,k,-4),k=0, 2)

     & / -0.1743872e+01, -0.1128921e+01, -0.2841969e+00 /

      DATA (am( 1,k,-4),k=0, 2)

     & /  0.3345755e+01,  0.3187765e+00,  0.1378124e+00 /

      DATA (am( 2,k,-4),k=0, 2)

     & / -0.2037615e+02,  0.4121687e+01,  0.2236520e+00 /

      DATA (am( 3,k,-4),k=0, 2)

     & / -0.4703104e+02,  0.5353087e+01, -0.1455347e+01 /

      DATA (am( 4,k,-4),k=0, 2)

     & / -0.1060230e+02, -0.1551122e+01, -0.1078863e+01 /

      DATA (am( 5,k,-4),k=0, 2)

     & /  0.5088892e+02, -0.8197304e+01,  0.8083451e+01 /

      DATA (am( 6,k,-4),k=0, 2)

     & / -0.2819070e+02,  0.4554086e+01, -0.5890995e+01 /

      DATA (am( 7,k,-4),k=0, 2)

     & / -0.1098238e+02,  0.2590096e+01, -0.8062879e+01 /


      DATA mexvec(-5) / 6 /

      DATA mlfvec(-5) / 2 /

      DATA ut1vec(-5) /  0.1619654e+02 /

      DATA ut2vec(-5) / -0.3367346e+01 /

      DATA alfvec(-5) /  0.5109891e-02 /

      DATA qmavec(-5) /  0.4500000e+01 /

      DATA (am( 0,k,-5),k=0, 2)

     & / -0.6800138e+01,  0.2493627e+01, -0.1075724e+01 /

      DATA (am( 1,k,-5),k=0, 2)

     & /  0.3036555e+01,  0.3324733e+00,  0.2008298e+00 /

      DATA (am( 2,k,-5),k=0, 2)

     & / -0.5203879e+01, -0.8493476e+01, -0.4523208e+01 /

      DATA (am( 3,k,-5),k=0, 2)

     & / -0.1524239e+01, -0.3411912e+01, -0.1771867e+02 /

      DATA (am( 4,k,-5),k=0, 2)

     & / -0.1099444e+02,  0.1320930e+01, -0.2353831e+01 /

      DATA (am( 5,k,-5),k=0, 2)

     & /  0.1699299e+02, -0.3565802e+02,  0.3566872e+02 /

      DATA (am( 6,k,-5),k=0, 2)

     & / -0.1465793e+02,  0.2703365e+02, -0.2176372e+02 /


      IF(q .LE. qmavec(ifl)) THEN

         pyct5m = 0.d0

         RETURN

      ENDIF


      IF(x .GE. 1.d0) THEN

         pyct5m = 0.d0

         RETURN

      ENDIF


      tmp = log(q/alfvec(ifl))

      IF(tmp .LE. 0.d0) THEN

         pyct5m = 0.d0

         RETURN

      ENDIF


      sb = log(tmp)

      sb1 = sb - 1.2d0

      sb2 = sb1*sb1


      DO 110 i = 0, nex

         af(i) = 0.d0

         sbx = 1.d0

         DO 100 k = 0, mlfvec(ifl)

            af(i) = af(i) + sbx*am(i,k,ifl)

            sbx = sb1*sbx

  100    CONTINUE

  110 CONTINUE


      y = -log(x)

      u = log(x/0.00001d0)


      part1 = af(1)*y**(1.d0+0.01d0*af(4))*(1.d0+ af(8)*u)

      part2 = af(0)*(1.d0 - x) + af(3)*x

      part3 = x*(1.d0-x)*(af(5)+af(6)*(1.d0-x)+af(7)*x*(1.d0-x))

      part4 = ut1vec(ifl)*log(1.d0-x) +

     &        af(2)*log(1.d0+exp(ut2vec(ifl))-x)


      pyct5m = exp(log(x) + part1 + part2 + part3 + part4)


C...Include threshold factor.

      pyct5m = pyct5m * (1.d0 - qmavec(ifl)/q)


      RETURN

      END