4 C-- ICH= 0 (1) if the Coulomb interaction is absent (present);
5 C-- ISPIN= JJ= 1,2,..,MSPIN denote increasing values of the pair
7 C-- To calculate the CF of two particles (with masses m1, m2 and
8 C-- charges C1, C2) the following information is required:
9 C-- AM= twice the reduced mass= 2*m1*m2/(m1+m2) in GeV/c^2,
10 C-- DM= (m1-m2)/(m1+m2), required if NS=2;
11 C-- AC= Bohr radius= 2*137.036*0.1973/(C1*C2*AMH) in fm;
12 C-- AC > 1.D9 if C1*C2= 0, AC < 0 if C1*C2 < 0;
13 C-- MSPIN= MSPINH(LL)= number of the values of the total pair spin S;
14 C-- FD= FDH(LL,JJ), RD= RDH(LL,JJ)= scattering length and effective
15 C-- radius for each value of the total pair spin S, JJ= 1,..,MSPIN; ;
16 C-- the corresponding square well parameters EB= EBH(LL,JJ), RB=
17 C-- RBH(LL,JJ) (required if NS=1) may be calculated by SEAR;
18 C-- if the effective range approximation is not valid (as is the case,
19 C-- e.g., for two-pion system) a code for calculation of the scattering
20 C-- amplitude should be supplemented;
21 C-- RHO= RHOH(LL,JJ), SF= SFH(LL,JJ), SE= SEH(LL) are spin factors;
22 C-- RHO= the probability that the spins j1 and j2 of the two particles
23 C-- will combine in a total spin S;
24 C-- RHO= (2*S+1)/[(2j1+1)*(2j2+1)] for unpolarized particles;
25 C-- RHO= (1-P1*P2)/4 and (3+P1*P2)/4 correspond to S=0 and 1 in the
26 C-- case of spin-1/2 particles with polarizations P1 and P2;
27 C-----------------------------------------------------------------------
28 IMPLICIT REAL*8 (A-H,O-Z)
29 COMMON/FSI_POC/AMN,AM1,AM2,CN,C1,C2,AC1,AC2
30 COMMON/FSI_PRF/PPX,PPY,PPZ,AK,AKS,
32 COMMON/FSI_SPIN/RHO(10)
33 COMMON/FSI_ACH/HPR,AC,ACH,ACHR,ISPIN,MSPIN
34 COMMON/FSI_NS/LL,NS,ICH,ISI,IQS,I3C,I3S
35 COMMON/FSI_FD/FD(10),RD(10)
36 COMMON/FSI_C/C(10),AM,AMS,DM
37 COMMON/FSI_CONS/PI,PI2,SPI,DR,W
40 COMMON/FSI_AAPI/AAPI(20,2)/FSI_AAND/AAND(20,4)
41 COMMON/FSI_SW/RB(10),EB(10),BK(10),CDK(10),SDK(10),
44 COMMON/LEDWEIGHT/WEIF,WEI,WEIN,ITEST,IRANPOS
46 DIMENSION FDH(30,10),RDH(30,10),EBH(30,10),RBH(30,10)
48 DIMENSION AM1H(30),AM2H(30),C1H(30),C2H(30),MSPINH(30)
49 C============= declarations pour l'appel de READ_FILE()============
56 C--- mass of the first and second particle
57 DATA AM1H/.9395656D0,.9382723D0,.9395656D0,3.7294D0,.13957D0,
58 C .13498D0,.13957D0, .9395656D0, .9382723D0,
59 C 4*.13957D0,4*.493677D0,
60 C 2*1.875613D0,2*2.808D0,2*.497672D0,
61 C 1.875613D0,2*.9382723D0, 4*0.D0/
62 DATA AM2H/.9395656D0,.9382723D0,.9382723D0,3.7294D0,.13957D0,
63 C .13498D0,.13957D0, 2*1.875613D0,
64 C 2*.493677D0,2*.9382723D0,
65 C 2*.493677D0,2*.9382723D0,
66 C 1.875613D0,3.7294D0,2.808D0,3.7294D0,
67 C 2*.497672D0,2*2.808D0,3.7294D0, 4*0.D0/
68 C--- charge of the first and second particle
69 DATA C1H/0.D0,1.D0,0.D0,2.D0, 1.D0,0.D0,1.D0,0.D0,1.D0,
70 C 3*1.D0,-1.D0,3*1.D0,-1.D0,
71 C 4*1.D0,2*0.D0,3*1.D0, 4*0.D0/
72 DATA C2H/0.D0,1.D0,1.D0,2.D0,-1.D0,0.D0,3*1.D0,
73 C -1.D0,3*1.D0,-1.D0,3*1.D0,
74 C 1.D0,2.D0,1.D0,2.D0,2*0.D0,2*1.D0,2.D0, 4*0.D0/
76 DATA MSPINH/3*2,4*1,2*2,8*1,3,1,2,1,2*1,2*2,1, 4*0/
77 C---Spin factors RHO vs (LL,ISPIN)
78 DATA RHOH/3*.25D0, 4*1.D0, 2*.3333D0, 8*1.D0,
79 C .1111D0,1.D0,.25D0,1.D0,2*1.D0,
80 1 .3333D0,.25D0,1.D0, 4*0.D0,
81 C 3*.75D0, 4*0.D0, 2*.6667D0, 8*0.D0,
82 C .3333D0,.0D0,.75D0,.0D0,2*0.D0,
83 2 .6667D0,.75D0,0.D0, 4*0.D0,
84 C 17*.0D0,.5556D0,3*0.D0, 5*0.D0,4*0.D0,210*0.D0/
85 C---Scattering length FD and effective radius RD in fm vs (LL,ISPIN)
86 DATA FDH/17.0D0,7.8D0,23.7D0,2230.1218D0,.225D0,.081D0,-.063D0,
88 C .137D0,-.071D0,-.148D0,.112D0,2*1.D-6,-.360D0,
89 1 2*1.D-6,1.344D0,6*1.D-6,-5.628D0, 4*0.D0,
90 C -10.8D0,2*-5.4D0,4*0.D0,-6.35D0,-11.88D0,8*0.D0,9*0.D0,4*0.D0,
92 DATA RDH/2.7D0,2.8D0,2.7D0,1.12139906D0,-44.36D0,64.0D0,784.9D0,
93 c--------|---------|---------|---------|---------|---------|---------|----------
94 C 477.9D0, 2.27D0, 9*0.D0,-69.973D0, 6*0.D0,3.529D0, 4*0.D0,
95 C 3*1.7D0,4*0.D0,2.0D0,2.63D0, 17*0.D0, 4*0.D0, 240*0.D0/
96 C---Corresponding square well parameters RB (width in fm) and
97 C-- EB =SQRT(-AM*U) (in GeV/c); U is the well height
98 DATA RBH/2.545739D0, 2.779789D0, 2.585795D0, 5.023544D0,
99 C .124673D0, .3925180D0,.09D0, 2.D0, 4.058058D0, 17*0.D0, 4*0.D0,
101 C 4*0.D0, 2.D0, 4.132163D0, 17*0.D0, 4*0.D0, 240*0.D0/
102 DATA EBH/.1149517D0, .1046257D0, .1148757D0, .1186010D0,
103 C .7947389D0,2.281208D0,8.7D0,.4D0,.1561219D0,17*0.D0,4*0.D0,
105 C 4*0.D0, .4D0, .1150687D0, 17*0.D0, 4*0.D0, 240*0.D0/
106 C=======< constants >========================
107 W=1/.1973D0 ! from fm to 1/GeV
111 DR=180.D0/PI ! from radian to degree
115 C---setting particle masses and charges
122 C ISI=1(0) the strong interaction between the two particles ON (OFF)
123 C IQS=1(0) the quantum statistics ON (OFF);
124 C should be OFF for nonidentical particles
125 C I3C=1(0) the Coulomb interaction with the nucleus ON (OFF)
126 C I3S=1(0) the strong interaction with the nucleus ON (OFF)
127 C ICH=1(0) if C1*C2 is different from 0 (is equal to 0)
128 C- to switch off the Coulomb force between the two particles
129 C put ICH=0 and substitute the strong amplitude parameters by
130 C the ones not affected by Coulomb interaction
135 IF(C1*C2.NE.0.D0) ICH=1
137 IF(C1+AM1.EQ.C2+AM2) IQS=1
138 I3S=0 ! only this option is available
145 write(*,*)'FSIINI ITEST ich iqs i3s isi i3c',ITEST,
146 + ICH,IQS,I3S,ISI,I3C
148 C==================================================================
152 FDH(J1,J2)=FDH(J1,J2)*W
153 RDH(J1,J2)=RDH(J1,J2)*W
154 3 RBH(J1,J2)=RBH(J1,J2)*W
155 C---calcul. twice the reduced mass (AM), the relative mass difference
156 C-- (DM) and the Bohr radius (AC)
157 AM=2*AM1*AM2/(AM1+AM2)
159 DM=(AM1-AM2)/(AM1+AM2)
162 IF(C12.NE.0.D0)AC=2*137.036D0/(C12*AM)
163 C---Setting spin factors
167 91 RHO(ISPIN)=RHOH(LL,ISPIN)
168 C---Integration limit AA in the spherical wave approximation
170 cc IF(NS.EQ.2.OR.NS.EQ.4)AA=.5D0 !!in 1/GeV --> 0.1 fm
171 IF(NS.EQ.2.OR.NS.EQ.4)AA=6.D0 !!in 1/GeV --> 1.2 fm
172 C---Setting scatt. length (FD), eff. radius (RD) and, if possible,
173 C-- also the corresp. square well parameters (EB, RB)
180 IF(LL.NE.8.AND.LL.NE.9)GOTO25
181 C---Resets FD and RD for a nucleon-deuteron system (LL=8,9)
184 RD(JJ)=AAND(2,JH)-2*AAND(3,JH)/AAND(1,JH)
185 C---Resets FD and RD for a pion-pion system (LL=5,6,7)
186 25 IF(LL.GT.7.OR.LL.LT.5)GOTO 24
187 IF(LL.EQ.7)FD(JJ)=AAPI(1,2)/AM
188 IF(LL.EQ.5)FD(JJ)=(.6667D0*AAPI(1,1)+.3333D0*AAPI(1,2))/AM
189 IF(LL.EQ.6)FD(JJ)=(.3333D0*AAPI(1,1)+.6667D0*AAPI(1,2))/AM
197 IF(LL.EQ.7)C(JJ)=1/DCMPLX(GPI2H,-AKH)
199 +C(JJ)=.6667D0/DCMPLX(GPI1H,-AKH)+.3333D0/DCMPLX(GPI2H,-AKH)
201 +C(JJ)=.3333D0/DCMPLX(GPI1H,-AKH)+.6667D0/DCMPLX(GPI2H,-AKH)
205 C---Calculation continues for any system (any LL)
208 C=======================================================
221 FUNCTION GPIPIold(X,J)
222 C--- GPIPI = k*COTG(DELTA), X=k^2
223 C-- J=1(2) corresponds to isospin=0(2)
224 IMPLICIT REAL*8 (A-H,O-Z)
225 c-- Include 'common_fsi_aapi.inc'
226 c-- Include 'common_fsi_c.inc'
227 COMMON/FSI_AAPI/AAPI(20,2)
228 COMMON/FSI_C/HELP(20),AM,AMS,DM
232 GPIPI=GPIPI*(1+(AAPI(3,J)-AAPI(1,J)**2)*XX+AAPI(4,J)*XX*XX)
233 GPIPI=GPIPI/(1+(AAPI(3,J)+AAPI(2,J)/AAPI(1,J))*XX)
238 C--- GPIN = k*COTG(DELTA), X=k^2
239 C-- J=1(2) corresponds to piN isospin=1/2(3/2)
240 IMPLICIT REAL*8 (A-H,O-Z)
241 c-- Include 'common_fsi_aapin.inc'
242 COMMON/FSI_AAPIN/AAPIN(20,2)
243 GPIN=1/AAPIN(1,J)+.5D0*AAPIN(2,J)*X