3 *AJW 1 version of CURR from KORALB.
4 SUBROUTINE CURR_CLEO(MNUM,PIM1,PIM2,PIM3,PIM4,HADCUR)
5 C ==================================================================
6 C AJW, 11/97 - based on original CURR from TAUOLA:
7 C hadronic current for 4 pi final state
8 C R. Fisher, J. Wess and F. Wagner Z. Phys C3 (1980) 313
9 C R. Decker Z. Phys C36 (1987) 487.
10 C M. Gell-Mann, D. Sharp, W. Wagner Phys. Rev. Lett 8 (1962) 261.
11 C BUT, rewritten to be more general and less "theoretical",
12 C using parameters tuned by Vasia and DSC.
13 C ==================================================================
15 COMMON / PARMAS / AMTAU,AMNUTA,AMEL,AMNUE,AMMU,AMNUMU
16 * ,AMPIZ,AMPI,AMRO,GAMRO,AMA1,GAMA1
17 * ,AMK,AMKZ,AMKST,GAMKST
19 REAL*4 AMTAU,AMNUTA,AMEL,AMNUE,AMMU,AMNUMU
20 * ,AMPIZ,AMPI,AMRO,GAMRO,AMA1,GAMA1
21 * ,AMK,AMKZ,AMKST,GAMKST
23 REAL PIM1(4),PIM2(4),PIM3(4),PIM4(4)
26 INTEGER K,L,MNUM,K1,K2,IRO,I,J,KK
27 REAL PA(4),PB(4),PAA(4)
29 REAL A,XM,XG,G1,G2,G,AMRO2,GAMRO2,AMRO3,GAMRO3,AMOM,GAMOM
30 REAL FRO,COEF1,FPI,COEF2,QQ,SK,DENOM,SIG,QQA,SS23,SS24,SS34,QP1P2
31 REAL QP1P3,QP1P4,P1P2,P1P3,P1P4,SIGN
33 COMPLEX ALF0,ALF1,ALF2,ALF3
34 COMPLEX LAM0,LAM1,LAM2,LAM3
35 COMPLEX BET1,BET2,BET3
36 COMPLEX FORM1,FORM2,FORM3,FORM4,FORM2PI
37 COMPLEX BWIGM,WIGFOR,FPIKM,FPIKMD
41 BWIGN(A,XM,XG)=1.0/CMPLX(A-XM**2,XM*XG)
42 C*******************************************************************************
44 C --- masses and constants
45 IF (G1.NE.12.924) THEN
51 COEF1=2.0*SQRT(3.0)/FPI**2
52 COEF2=FRO*G ! overall constant for the omega current
53 COEF2= COEF2*0.56 ! factor 0.56 reduces contribution of omega from 68% to 40 %
55 C masses and widths for for rho-prim and rho-bis:
68 C Amplitudes for (pi-pi-pi0pi+) -> PS, rho0, rho-, rho+, omega.
69 AMPL(1) = CMPLX(PKORB(3,31)*COEF1,0.)
70 AMPL(2) = CMPLX(PKORB(3,32)*COEF1,0.)*CEXP(CMPLX(0.,PKORB(3,42)))
71 AMPL(3) = CMPLX(PKORB(3,33)*COEF1,0.)*CEXP(CMPLX(0.,PKORB(3,43)))
72 AMPL(4) = CMPLX(PKORB(3,34)*COEF1,0.)*CEXP(CMPLX(0.,PKORB(3,44)))
73 AMPL(5) = CMPLX(PKORB(3,35)*COEF2,0.)*CEXP(CMPLX(0.,PKORB(3,45)))
74 C Amplitudes for (pi0pi0pi0pi-) -> PS, rho-.
75 AMPL(6) = CMPLX(PKORB(3,36)*COEF1)
76 AMPL(7) = CMPLX(PKORB(3,37)*COEF1)
78 C rho' contributions to rho' -> pi-omega:
79 ALF0 = CMPLX(PKORB(3,51),0.0)
80 ALF1 = CMPLX(PKORB(3,52)*AMRO**2,0.0)
81 ALF2 = CMPLX(PKORB(3,53)*AMRO2**2,0.0)
82 ALF3 = CMPLX(PKORB(3,54)*AMRO3**2,0.0)
83 C rho' contribtions to rho' -> rhopipi:
84 LAM0 = CMPLX(PKORB(3,55),0.0)
85 LAM1 = CMPLX(PKORB(3,56)*AMRO**2,0.0)
86 LAM2 = CMPLX(PKORB(3,57)*AMRO2**2,0.0)
87 LAM3 = CMPLX(PKORB(3,58)*AMRO3**2,0.0)
88 C rho contributions to rhopipi, rho -> 2pi:
89 BET1 = CMPLX(PKORB(3,59)*AMRO**2,0.0)
90 BET2 = CMPLX(PKORB(3,60)*AMRO2**2,0.0)
91 BET3 = CMPLX(PKORB(3,61)*AMRO3**2,0.0)
94 C**************************************************
96 C --- initialization of four vectors
101 PAA(K)=PIM1(K)+PIM2(K)+PIM3(K)+PIM4(K)
108 C ===================================================================
109 C pi- pi- p0 pi+ case ====
110 C ===================================================================
111 QQ=PAA(4)**2-PAA(3)**2-PAA(2)**2-PAA(1)**2
113 C Add M(4pi)-dependence to rhopipi channels:
114 FORM4= LAM0+LAM1*BWIGN(QQ,AMRO,GAMRO)
115 * +LAM2*BWIGN(QQ,AMRO2,GAMRO2)
116 * +LAM3*BWIGN(QQ,AMRO3,GAMRO3)
118 C --- loop over five contributions of the rho-pi-pi
124 ELSEIF (K2.EQ.3) THEN
128 ELSEIF (K1.EQ.3) THEN
138 SK=(PP(K1,4)+PP(K2,4))**2-(PP(K1,3)+PP(K2,3))**2
139 $ -(PP(K1,2)+PP(K2,2))**2-(PP(K1,1)+PP(K2,1))**2
141 C -- definition of AA matrix
147 C ... and the rest ...
149 IF (L.NE.K1.AND.L.NE.K2) THEN
150 DENOM=(PAA(4)-PP(L,4))**2-(PAA(3)-PP(L,3))**2
151 $ -(PAA(2)-PP(L,2))**2-(PAA(1)-PP(L,1))**2
157 $ -SIG*(PAA(I)-2.0*PP(L,I))*(PAA(J)-PP(L,J))/DENOM
162 C --- lets add something to HADCURR
163 C FORM1= FPIKM(SQRT(SK),AMPI,AMPI) *FPIKM(SQRT(QQ),AMPI,AMPI)
164 C FORM1= AMPL(1)+AMPR*FPIKM(SQRT(SK),AMPI,AMPI)
166 FORM2PI= BET1*BWIGM(SK,AMRO,GAMRO,AMPA,AMPI)
167 1 +BET2*BWIGM(SK,AMRO2,GAMRO2,AMPA,AMPI)
168 2 +BET3*BWIGM(SK,AMRO3,GAMRO3,AMPA,AMPI)
169 FORM1= AMPL(1)+AMPR*FORM2PI
173 HADCUR(I)=HADCUR(I)+FORM1*FORM4*AA(I,J)*(PP(K1,J)-PP(K2,J))
175 C --- end of the rho-pi-pi current (5 possibilities)
178 C ===================================================================
179 C Now modify the coefficient for the omega-pi current: =
180 C ===================================================================
181 IF (AMPL(5).EQ.CMPLX(0.,0.)) GOTO 311
183 C Overall rho+rhoprime for the 4pi system:
184 C FORM2=AMPL(5)*(BWIGN(QQ,AMRO,GAMRO)+ELPHA*BWIGN(QQ,AMROP,GAMROP))
185 C Modified M(4pi)-dependence:
186 FORM2=AMPL(5)*(ALF0+ALF1*BWIGN(QQ,AMRO,GAMRO)
187 * +ALF2*BWIGN(QQ,AMRO2,GAMRO2)
188 * +ALF3*BWIGN(QQ,AMRO3,GAMRO3))
190 C --- there are two possibilities for omega current
191 C --- PA PB are corresponding first and second pi-s
197 C --- lorentz invariants
210 IF (K.EQ.4) SIGN= 1.0
211 QQA=QQA+SIGN*(PAA(K)-PA(K))**2
212 SS23=SS23+SIGN*(PB(K) +PIM3(K))**2
213 SS24=SS24+SIGN*(PB(K) +PIM4(K))**2
214 SS34=SS34+SIGN*(PIM3(K)+PIM4(K))**2
215 QP1P2=QP1P2+SIGN*(PAA(K)-PA(K))*PB(K)
216 QP1P3=QP1P3+SIGN*(PAA(K)-PA(K))*PIM3(K)
217 QP1P4=QP1P4+SIGN*(PAA(K)-PA(K))*PIM4(K)
218 P1P2=P1P2+SIGN*PA(K)*PB(K)
219 P1P3=P1P3+SIGN*PA(K)*PIM3(K)
220 P1P4=P1P4+SIGN*PA(K)*PIM4(K)
223 C omega -> rho pi for the 3pi system:
224 C FORM3=BWIGN(QQA,AMOM,GAMOM)*(BWIGN(SS23,AMRO,GAMRO)+
225 C $ BWIGN(SS24,AMRO,GAMRO)+BWIGN(SS34,AMRO,GAMRO))
226 C No omega -> rho pi; just straight omega:
227 FORM3=BWIGN(QQA,AMOM,GAMOM)
230 HADCUR(K)=HADCUR(K)+FORM2*FORM3*(
231 $ PB (K)*(QP1P3*P1P4-QP1P4*P1P3)
232 $ +PIM3(K)*(QP1P4*P1P2-QP1P2*P1P4)
233 $ +PIM4(K)*(QP1P2*P1P3-QP1P3*P1P2) )
239 C ===================================================================
240 C pi0 pi0 p0 pi- case ====
241 C ===================================================================
242 QQ=PAA(4)**2-PAA(3)**2-PAA(2)**2-PAA(1)**2
244 C --- loop over three contribution of the non-omega current
246 SK=(PP(K,4)+PIM4(4))**2-(PP(K,3)+PIM4(3))**2
247 $ -(PP(K,2)+PIM4(2))**2-(PP(K,1)+PIM4(1))**2
249 C -- definition of AA matrix
256 C ... and the rest ...
259 DENOM=(PAA(4)-PP(L,4))**2-(PAA(3)-PP(L,3))**2
260 $ -(PAA(2)-PP(L,2))**2-(PAA(1)-PP(L,1))**2
266 $ -SIG*(PAA(I)-2.0*PP(L,I))*(PAA(J)-PP(L,J))/DENOM
271 C --- lets add something to HADCURR
272 C FORM1= FPIKM(SQRT(SK),AMPI,AMPI) *FPIKMD(SQRT(QQ),AMPI,AMPI)
273 CCCCCCCCCCCCC FORM1=WIGFOR(SK,AMRO,GAMRO) (tests)
274 C FORM1= FPIKM(SQRT(SK),AMPI,AMPI) *FPIKM(SQRT(QQ),AMPI,AMPI)
275 FORM1 = AMPL(6)+AMPL(7)*FPIKM(SQRT(SK),AMPI,AMPI)
279 HADCUR(I)=HADCUR(I)+FORM1*AA(I,J)*(PP(K,J)-PP(4,J))
281 C --- end of the non omega current (3 possibilities)