Some function moved to AliZDC
[u/mrichter/AliRoot.git] / GEANT321 / gstrag / gstdn.F
1 *
2 * $Id$
3 *
4 * $Log$
5 * Revision 1.1.1.1  1995/10/24 10:21:39  cernlib
6 * Geant
7 *
8 *
9 #include "geant321/pilot.h"
10 *CMZ :  3.21/02 29/03/94  15.41.25  by  S.Giani
11 *-- Author :
12       FUNCTION GSTDN(LGE)
13 *   ********************************************************************
14 *   *                                                                  *
15 *   *    dN^2/dxdE function for the preparation of the table as in     *
16 *   *    Grishin,Ermilova,Kotelnikov,NIM A307(1991),273                *
17 *   *                                                                  *
18 *   *    ==> Called by : GSTTAB                                        *
19 *   *        Author    : P. Nevski                                     *
20 *   *                                                                  *
21 *   ********************************************************************
22 #include "geant321/gconsp.inc"
23 #include "geant321/gcstra.inc"
24 *
25       REAL LGE
26       COMPLEX I,CEPS1,C1,C2
27       SEXP(X) = EXP(MAX(X,-99.))
28 *
29 *     ------------------------------------------------------------------
30       I=(0.,1.)
31       E=EXP(LGE)
32 *
33 *    Epsilon-1
34       E0     = MAX(LGE,EMIN)
35       E2INV  = 1/E**2
36       CEPS1  =  CMPLX(GSTINT(LGE,EMM,EPSR,NTAB)*E2INV,
37      +       SEXP(GSTINT(E0,EMM,EPSI,NTAB)))
38       C1     = 1/GAMMA2-CEPS1*BETA2
39       C2     = C1/(1+CEPS1)*LOG(2*BETA2*MEEV/(E*C1))
40       GSTDN  = S2/BETA2 * (-2*AIMAG(C2)/(WP2*PI) + (1-SEXP(GSTINT(E0
41      +, EMM,FINT,NTAB)))*E2INV) * E
42       END