[u/mrichter/AliRoot.git] / PDF / spdf / dgpho1.F

*
* $Id$
*
* $Log$
* Revision 1.4  2000/09/18 10:02:35  hristov
* Makefile added to PDF8
*
* Revision 1.1.1.2  1996/10/30 08:28:02  cernlib
* Version 7.04
*
* Revision 1.1.1.1  1996/04/12 15:29:15  plothow
* Version 7.01
*
*
#include "pdf/pilot.h"
       SUBROUTINE DGPHO1(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"
#if defined(CERNLIB_DOUBLE)
      DOUBLE PRECISION
#endif
#if defined(CERNLIB_SINGLE)
      REAL
#endif
     +        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...         nf=3 for   1< Q2 <32  GeV2
C...         nf=4 for  32< Q2 <200 GeV2
C...         nf=5 for 200< Q2 <1D4 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
       Q2 = DQ*DQ
         IF (Q2.LT.32.0D0) NFL=3
         IF((Q2.GE.32.0D0).AND.(Q2.LT.200.0D0)) NFL=4
         IF (Q2.GE.200.0D0) NFL=5
C
C...calculations
       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)=1.0D0
        IF(NFL.EQ.3) THEN
          E(2)=9.0D0
        ELSEIF(NFL.EQ.4) THEN
          E(2)=10.0D0
        ELSEIF(NFL.EQ.5) THEN
          E(2)=55.0D0/6.0D0
        ENDIF
        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
        IF (NFL.EQ.3) THEN
            DUB=ALPEM*1.D0/6.D0*(XQPOM(2)+9.D0*XQPOM(1))
            DDB=ALPEM*1.D0/6.D0*(XQPOM(2)-9.D0/2.D0*XQPOM(1))
            DSB=DDB
            DCB=0.D0
            DBB=0.D0
        ELSEIF (NFL.EQ.4) THEN
            DUB=ALPEM*1.D0/8.D0*(XQPOM(2)+6.D0*XQPOM(1))
            DCB=DUB
            DDB=ALPEM*1.D0/8.D0*(XQPOM(2)-6.D0*XQPOM(1))
            DSB=DDB
            DBB=0.D0
        ELSEIF (NFL.EQ.5) THEN
            DUB=ALPEM*1.D0/10.D0*(XQPOM(2)+15.D0/2.D0*XQPOM(1))
            DCB=DUB
            DDB=ALPEM*1.D0/10.D0*(XQPOM(2)-5.D0*XQPOM(1))
            DSB=DDB
            DBB=DDB
        ENDIF
      DUV=DUB
      DDV=DDB
C
      RETURN
      END
Commit	Line	Data
21886bb6	1	*
	2	* $Id$
	3	*
	4	* $Log$
7ef50f50	5	* Revision 1.4 2000/09/18 10:02:35 hristov
	6	* Makefile added to PDF8
	7	*
21886bb6	8	* Revision 1.1.1.2 1996/10/30 08:28:02 cernlib
	9	* Version 7.04
	10	*
	11	* Revision 1.1.1.1 1996/04/12 15:29:15 plothow
	12	* Version 7.01
	13	*
	14	*
	15	#include "pdf/pilot.h"
	16	SUBROUTINE DGPHO1(DX,DQ,DUV,DDV,DUB,DDB,DSB,DCB,DBB,DGL)
	17	C********************************************************************
	18	C* *
	19	C* Parametrization of parton distribution functions *
	20	C* in the photon (LO analysis) - full solution of AP eq.! *
	21	C* *
	22	C* authors: M.Drees and K.Grassie (DG) *
	23	C* /Z. Phys. C28 (1985) 451/ *
	24	C* *
	25	C* Prepared by: *
	26	C* Krzysztof Charchula, DESY *
	27	C* bitnet: F1PCHA@DHHDESY3 *
	28	C* decnet: 13313::CHARCHULA *
	29	C* *
	30	C* Modified by: *
	31	C* H. Plothow-Besch/CERN-PPE *
	32	C* *
	33	C********************************************************************
	34	C
	35	#include "pdf/impdp.inc"
7ef50f50	36	#if defined(CERNLIB_DOUBLE)
	37	DOUBLE PRECISION
	38	#endif
	39	#if defined(CERNLIB_SINGLE)
	40	REAL
	41	#endif
21886bb6	42	+ A(3,4,3),AT(3),
	43	+ B(5,4,2,3),BT(5,2),XQPOM(2),E(2),
	44	+ DX,DQ,DUV,DDV,DUB,DDB,DSB,DCB,DBB,DGL
	45	PARAMETER (ALPEM=7.29927D-3, PI=3.141592D0)
	46	PARAMETER (ALAM=0.4D0)
	47	C...comments
	48	C...--------------------------------------------------
	49	C... nf=3 for 1< Q2 <32 GeV2
	50	C... nf=4 for 32< Q2 <200 GeV2
	51	C... nf=5 for 200< Q2 <1D4 GeV2
	52	C...--------------------------------------------------
	53	C
	54	C...initialization of gluon parameters array for DG
	55	DATA (((A(I,J,K),I=1,3),J=1,4),K=1,3)/
	56	> -0.20700, -0.19870, 5.1190,
	57	> 0.61580, 0.62570, -0.2752,
	58	> 1.07400, 8.35200, -6.9930,
	59	> 0.00000, 5.02400, 2.2980,
	60	> 0.8926D-2,0.0509, -0.2313,
	61	> 0.65940, 0.27740, 0.1382,
	62	> 0.47660, -0.39060, 6.5420,
	63	> 0.01975, -0.32120, 0.5162,
	64	> 0.03197, -0.618D-2,-0.1216,
	65	> 1.01800, 0.94760, 0.9047,
	66	> 0.24610, -0.60940, 2.6530,
	67	> 0.02707, -0.01067, 0.2003D-2/
	68	C
	69	C...initialization of quark parameters array for DG
	70	DATA (((B(I,J,K,1),I=1,5),J=1,4),K=1,2)/
	71	> 2.2850, 6.0730, -0.4202, -0.0808, 0.0553,
	72	> -0.0153, -0.8132, 0.0178, 0.6346, 1.1360,
	73	> 1.33D3, -41.310, 0.9216, 1.2080, 0.9512,
	74	> 4.2190, 3.1650, 0.1800, 0.2030, 0.0116,
	75	> 16.690, 0.1760, -0.0208, -0.0168, -0.1986,
	76	> -0.7916, 0.0479, 0.3386D-2, 1.3530, 1.1000,
	77	> 1.0990D3, 1.0470, 4.8530, 1.4260, 1.1360,
	78	> 4.4280, 0.0250, 0.8404, 1.2390, -0.2779/
	79	DATA (((B(I,J,K,2),I=1,5),J=1,4),K=1,2)/
	80	> -0.3711, -0.1717, 0.08766, -0.8915, -0.1816,
	81	> 1.0610, 0.7815, 0.02197, 0.2857, 0.5866,
	82	> 4.7580, 1.5350, 0.10960, 2.9730, 2.4210,
	83	> -0.0150, 0.7067D-2,0.20400, 0.1185, 0.4059,
	84	> -0.1207, 25.000, -0.01230, -0.0919, 0.02015,
	85	> 1.0710, -1.6480, 1.16200, 0.7912, 0.9869,
	86	> 1.9770, -0.01563, 0.48240, 0.6397, -0.07036,
	87	> -0.8625D-2,6.4380, -0.01100, 2.3270, 0.01694/
	88	DATA (((B(I,J,K,3),I=1,5),J=1,4),K=1,2)/
	89	> 15.8, 2.742, 0.02917, -0.0342, -0.02302,
	90	> -0.9464, -0.7332, 0.04657, 0.7196, 0.9229,
	91	> -0.5, 0.7148, 0.1785, 0.7338, 0.5873,
	92	> -0.2118, 3.287, 0.04811, 0.08139,-0.79D-4,
	93	> 6.734, 59.88, -0.3226D-2,-0.03321, 0.1059,
	94	> -1.008, -2.983, 0.8432, 0.9475, 0.6954,
	95	> -0.08594, 4.48, 0.3616, -0.3198, -0.6663,
	96	> 0.07625, 0.9686, 0.1383D-2, 0.02132, 0.3683/
	97	C
	98	C...specification of sets
	99	Q2 = DQ*DQ
	100	IF (Q2.LT.32.0D0) NFL=3
	101	IF((Q2.GE.32.0D0).AND.(Q2.LT.200.0D0)) NFL=4
	102	IF (Q2.GE.200.0D0) NFL=5
	103	C
	104	C...calculations
	105	ALAM2=ALAM**2
106	T=LOG(Q2/ALAM2)
107	LF=NFL-2
108	C
109	C...gluons
110	DO 11 I=1,3
111	AT(I)=A(I,1,LF)TA(I,2,LF)+A(I,3,LF)T**(-A(I,4,LF))
112	11 CONTINUE
113	POMG=AT(1)DXAT(2)(1.D0-DX)**AT(3)
114	DGL=POMG*ALPEM
115	C
116	C...quarks
117	E(1)=1.0D0
118	IF(NFL.EQ.3) THEN
119	E(2)=9.0D0
120	ELSEIF(NFL.EQ.4) THEN
121	E(2)=10.0D0
122	ELSEIF(NFL.EQ.5) THEN
123	E(2)=55.0D0/6.0D0
124	ENDIF
125	DO 13 J=1,2
126	DO 15 I=1,5
127	BTP=B(I,1,J,LF)T*B(I,2,J,LF)
128	BT(I,J)=BTP+B(I,3,J,LF)T*(-B(I,4,J,LF))
129	15 CONTINUE
130	13 CONTINUE
131	C
132	C...singlet & non-singlet combinations
133	DO 17 J=1,2
134	POM1=DX(DXDX+(1.D0-DX)*2)/(BT(1,J)-BT(2,J)LOG(1.D0-DX))
135	POM2=BT(3,J)DXBT(4,J)(1.D0-DX)**BT(5,J)
136	XQPOM(J)=E(J)*POM1+POM2
137	17 CONTINUE
138	C
139	C...quarks flavours
140	IF (NFL.EQ.3) THEN
141	DUB=ALPEM1.D0/6.D0(XQPOM(2)+9.D0*XQPOM(1))
142	DDB=ALPEM1.D0/6.D0(XQPOM(2)-9.D0/2.D0*XQPOM(1))
143	DSB=DDB
144	DCB=0.D0
145	DBB=0.D0
146	ELSEIF (NFL.EQ.4) THEN
147	DUB=ALPEM1.D0/8.D0(XQPOM(2)+6.D0*XQPOM(1))
148	DCB=DUB
149	DDB=ALPEM1.D0/8.D0(XQPOM(2)-6.D0*XQPOM(1))
150	DSB=DDB
151	DBB=0.D0
152	ELSEIF (NFL.EQ.5) THEN
153	DUB=ALPEM1.D0/10.D0(XQPOM(2)+15.D0/2.D0*XQPOM(1))
154	DCB=DUB
155	DDB=ALPEM1.D0/10.D0(XQPOM(2)-5.D0*XQPOM(1))
156	DSB=DDB
157	DBB=DDB
158	ENDIF
159	DUV=DUB
160	DDV=DDB
161	C
162	RETURN
163	END