[u/mrichter/AliRoot.git] / PDF / spdf / dgpho2.F

*
* $Id$
*
* $Log$
* Revision 1.1.1.2  1996/10/30 08:28:04  cernlib
* Version 7.04
*
* Revision 1.1.1.1  1996/04/12 15:29:15  plothow
* Version 7.01
*
*
#include "pdf/pilot.h"
       SUBROUTINE DGPHO2(DX,DQ,DUV,DDV,DUB,DDB,DSB,DCB,DBB,DGL)
C********************************************************************
C*                                                                  *
C*    Parametrization of parton distribution functions              *
C*    in the photon (LO analysis) - full  solution of AP eq.!       *
C*                                                                  *
C* authors:  M.Drees and K.Grassie (DG)                             *
C*          /Z. Phys. C28 (1985) 451/                               *
C*                                                                  *
C* Prepared by:                                                     *
C*             Krzysztof Charchula, DESY                            *
C*             bitnet: F1PCHA@DHHDESY3                              *
C*             decnet: 13313::CHARCHULA                             *
C*                                                                  *
C* Modified by:                                                     *
C*             H. Plothow-Besch/CERN-PPE                            *
C*                                                                  *
C********************************************************************
C
#include "pdf/impdp.inc"
#include "pdf/expdp.inc"
     +        A(3,4,3),AT(3),
     +        B(5,4,2,3),BT(5,2),XQPOM(2),E(2),
     +        DX,DQ,DUV,DDV,DUB,DDB,DSB,DCB,DBB,DGL
      PARAMETER (ALPEM=7.29927D-3, PI=3.141592D0)
      PARAMETER (ALAM=0.4D0)
C...comments
C...--------------------------------------------------
C...        with nf=3 (valid for   1< Q2 <50  GeV2)
C...--------------------------------------------------
C
C...initialization of gluon parameters array for DG
        DATA (((A(I,J,K),I=1,3),J=1,4),K=1,3)/
     >    -0.20700, -0.19870,  5.1190,
     >     0.61580,  0.62570, -0.2752,
     >     1.07400,  8.35200, -6.9930,
     >     0.00000,  5.02400,  2.2980,
     >     0.8926D-2,0.0509,  -0.2313,
     >     0.65940,  0.27740,  0.1382,
     >     0.47660, -0.39060,  6.5420,
     >     0.01975, -0.32120,  0.5162,
     >     0.03197, -0.618D-2,-0.1216,
     >     1.01800,  0.94760,  0.9047,
     >     0.24610, -0.60940,  2.6530,
     >     0.02707, -0.01067,  0.2003D-2/
C
C...initialization of quark parameters array for DG
        DATA (((B(I,J,K,1),I=1,5),J=1,4),K=1,2)/
     >     2.2850,   6.0730,  -0.4202,   -0.0808,  0.0553,
     >    -0.0153,  -0.8132,   0.0178,    0.6346,  1.1360,
     >     1.33D3, -41.310,    0.9216,    1.2080,  0.9512,
     >     4.2190,   3.1650,   0.1800,    0.2030,  0.0116,
     >    16.690,    0.1760,  -0.0208,   -0.0168, -0.1986,
     >    -0.7916,   0.0479,   0.3386D-2, 1.3530,  1.1000,
     >     1.0990D3, 1.0470,   4.8530,    1.4260,  1.1360,
     >     4.4280,   0.0250,   0.8404,    1.2390, -0.2779/
        DATA (((B(I,J,K,2),I=1,5),J=1,4),K=1,2)/
     >    -0.3711,  -0.1717,   0.08766,  -0.8915, -0.1816,
     >     1.0610,   0.7815,   0.02197,   0.2857,  0.5866,
     >     4.7580,   1.5350,   0.10960,   2.9730,  2.4210,
     >    -0.0150,   0.7067D-2,0.20400,   0.1185,  0.4059,
     >    -0.1207,  25.000,   -0.01230,  -0.0919,  0.02015,
     >     1.0710,  -1.6480,   1.16200,   0.7912,  0.9869,
     >     1.9770,  -0.01563,  0.48240,   0.6397, -0.07036,
     >    -0.8625D-2,6.4380,  -0.01100,   2.3270,  0.01694/
        DATA (((B(I,J,K,3),I=1,5),J=1,4),K=1,2)/
     >    15.8,      2.742,    0.02917,  -0.0342, -0.02302,
     >    -0.9464,  -0.7332,   0.04657,   0.7196,  0.9229,
     >    -0.5,      0.7148,   0.1785,    0.7338,  0.5873,
     >    -0.2118,   3.287,    0.04811,   0.08139,-0.79D-4,
     >     6.734,   59.88,    -0.3226D-2,-0.03321, 0.1059,
     >    -1.008,   -2.983,    0.8432,    0.9475,  0.6954,
     >    -0.08594,  4.48,     0.3616,   -0.3198, -0.6663,
     >     0.07625,  0.9686,   0.1383D-2, 0.02132, 0.3683/
C
C...specification of sets
         NFL=3
C
C...calculations
       Q2 = DQ*DQ
       ALAM2=ALAM**2
       T=LOG(Q2/ALAM2)
       LF=NFL-2
C
C...gluons
        DO 11 I=1,3
          AT(I)=A(I,1,LF)*T**A(I,2,LF)+A(I,3,LF)*T**(-A(I,4,LF))
 11     CONTINUE
        POMG=AT(1)*DX**AT(2)*(1.D0-DX)**AT(3)
        DGL=POMG*ALPEM
C
C...quarks
        E(1)=1.D0
        E(2)=9.D0
        DO 13 J=1,2
          DO 15 I=1,5
            BTP=B(I,1,J,LF)*T**B(I,2,J,LF)
            BT(I,J)=BTP+B(I,3,J,LF)*T**(-B(I,4,J,LF))
 15       CONTINUE
 13     CONTINUE
C
C...singlet & non-singlet combinations
        DO 17 J=1,2
          POM1=DX*(DX*DX+(1.D0-DX)**2)/(BT(1,J)-BT(2,J)*LOG(1.D0-DX))
          POM2=BT(3,J)*DX**BT(4,J)*(1.D0-DX)**BT(5,J)
          XQPOM(J)=E(J)*POM1+POM2
 17     CONTINUE
C
C...quarks flavours
      DUB=ALPEM*1.D0/6.D0*(XQPOM(2)+9.D0*XQPOM(1))
      DUV=DUB
      DDB=ALPEM*1.D0/6.D0*(XQPOM(2)-9.D0/2.D0*XQPOM(1))
      DDV=DDB
      DSB=DDB
      DCB=0.D0
      DBB=0.D0
C
      RETURN
      END
Commit	Line	Data
fe4da5cc	1	*
	2	* $Id$
	3	*
	4	* $Log$
	5	* Revision 1.1.1.2 1996/10/30 08:28:04 cernlib
	6	* Version 7.04
	7	*
	8	* Revision 1.1.1.1 1996/04/12 15:29:15 plothow
	9	* Version 7.01
	10	*
	11	*
	12	#include "pdf/pilot.h"
	13	SUBROUTINE DGPHO2(DX,DQ,DUV,DDV,DUB,DDB,DSB,DCB,DBB,DGL)
	14	C********************************************************************
	15	C* *
	16	C* Parametrization of parton distribution functions *
	17	C* in the photon (LO analysis) - full solution of AP eq.! *
	18	C* *
	19	C* authors: M.Drees and K.Grassie (DG) *
	20	C* /Z. Phys. C28 (1985) 451/ *
	21	C* *
	22	C* Prepared by: *
	23	C* Krzysztof Charchula, DESY *
	24	C* bitnet: F1PCHA@DHHDESY3 *
	25	C* decnet: 13313::CHARCHULA *
	26	C* *
	27	C* Modified by: *
	28	C* H. Plothow-Besch/CERN-PPE *
	29	C* *
	30	C********************************************************************
	31	C
	32	#include "pdf/impdp.inc"
	33	#include "pdf/expdp.inc"
	34	+ A(3,4,3),AT(3),
	35	+ B(5,4,2,3),BT(5,2),XQPOM(2),E(2),
	36	+ DX,DQ,DUV,DDV,DUB,DDB,DSB,DCB,DBB,DGL
	37	PARAMETER (ALPEM=7.29927D-3, PI=3.141592D0)
	38	PARAMETER (ALAM=0.4D0)
	39	C...comments
	40	C...--------------------------------------------------
	41	C... with nf=3 (valid for 1< Q2 <50 GeV2)
	42	C...--------------------------------------------------
	43	C
	44	C...initialization of gluon parameters array for DG
	45	DATA (((A(I,J,K),I=1,3),J=1,4),K=1,3)/
	46	> -0.20700, -0.19870, 5.1190,
	47	> 0.61580, 0.62570, -0.2752,
	48	> 1.07400, 8.35200, -6.9930,
	49	> 0.00000, 5.02400, 2.2980,
	50	> 0.8926D-2,0.0509, -0.2313,
	51	> 0.65940, 0.27740, 0.1382,
	52	> 0.47660, -0.39060, 6.5420,
	53	> 0.01975, -0.32120, 0.5162,
	54	> 0.03197, -0.618D-2,-0.1216,
	55	> 1.01800, 0.94760, 0.9047,
	56	> 0.24610, -0.60940, 2.6530,
	57	> 0.02707, -0.01067, 0.2003D-2/
	58	C
	59	C...initialization of quark parameters array for DG
	60	DATA (((B(I,J,K,1),I=1,5),J=1,4),K=1,2)/
	61	> 2.2850, 6.0730, -0.4202, -0.0808, 0.0553,
	62	> -0.0153, -0.8132, 0.0178, 0.6346, 1.1360,
	63	> 1.33D3, -41.310, 0.9216, 1.2080, 0.9512,
	64	> 4.2190, 3.1650, 0.1800, 0.2030, 0.0116,
65	> 16.690, 0.1760, -0.0208, -0.0168, -0.1986,
66	> -0.7916, 0.0479, 0.3386D-2, 1.3530, 1.1000,
67	> 1.0990D3, 1.0470, 4.8530, 1.4260, 1.1360,
68	> 4.4280, 0.0250, 0.8404, 1.2390, -0.2779/
69	DATA (((B(I,J,K,2),I=1,5),J=1,4),K=1,2)/
70	> -0.3711, -0.1717, 0.08766, -0.8915, -0.1816,
71	> 1.0610, 0.7815, 0.02197, 0.2857, 0.5866,
72	> 4.7580, 1.5350, 0.10960, 2.9730, 2.4210,
73	> -0.0150, 0.7067D-2,0.20400, 0.1185, 0.4059,
74	> -0.1207, 25.000, -0.01230, -0.0919, 0.02015,
75	> 1.0710, -1.6480, 1.16200, 0.7912, 0.9869,
76	> 1.9770, -0.01563, 0.48240, 0.6397, -0.07036,
77	> -0.8625D-2,6.4380, -0.01100, 2.3270, 0.01694/
78	DATA (((B(I,J,K,3),I=1,5),J=1,4),K=1,2)/
79	> 15.8, 2.742, 0.02917, -0.0342, -0.02302,
80	> -0.9464, -0.7332, 0.04657, 0.7196, 0.9229,
81	> -0.5, 0.7148, 0.1785, 0.7338, 0.5873,
82	> -0.2118, 3.287, 0.04811, 0.08139,-0.79D-4,
83	> 6.734, 59.88, -0.3226D-2,-0.03321, 0.1059,
84	> -1.008, -2.983, 0.8432, 0.9475, 0.6954,
85	> -0.08594, 4.48, 0.3616, -0.3198, -0.6663,
86	> 0.07625, 0.9686, 0.1383D-2, 0.02132, 0.3683/
87	C
88	C...specification of sets
89	NFL=3
90	C
91	C...calculations
92	Q2 = DQ*DQ
93	ALAM2=ALAM**2
94	T=LOG(Q2/ALAM2)
95	LF=NFL-2
96	C
97	C...gluons
98	DO 11 I=1,3
99	AT(I)=A(I,1,LF)TA(I,2,LF)+A(I,3,LF)T**(-A(I,4,LF))
100	11 CONTINUE
101	POMG=AT(1)DXAT(2)(1.D0-DX)**AT(3)
102	DGL=POMG*ALPEM
103	C
104	C...quarks
105	E(1)=1.D0
106	E(2)=9.D0
107	DO 13 J=1,2
108	DO 15 I=1,5
109	BTP=B(I,1,J,LF)T*B(I,2,J,LF)
110	BT(I,J)=BTP+B(I,3,J,LF)T*(-B(I,4,J,LF))
111	15 CONTINUE
112	13 CONTINUE
113	C
114	C...singlet & non-singlet combinations
115	DO 17 J=1,2
116	POM1=DX(DXDX+(1.D0-DX)*2)/(BT(1,J)-BT(2,J)LOG(1.D0-DX))
117	POM2=BT(3,J)DXBT(4,J)(1.D0-DX)**BT(5,J)
118	XQPOM(J)=E(J)*POM1+POM2
119	17 CONTINUE
120	C
121	C...quarks flavours
122	DUB=ALPEM1.D0/6.D0(XQPOM(2)+9.D0*XQPOM(1))
123	DUV=DUB
124	DDB=ALPEM1.D0/6.D0(XQPOM(2)-9.D0/2.D0*XQPOM(1))
125	DDV=DDB
126	DSB=DDB
127	DCB=0.D0
128	DBB=0.D0
129	C
130	RETURN
131	END