C++InterfacetoTauola
new.f
1 ************************************************************************
2 * default Tauola resonance form factor (taken from tauola function
3 * FORM1):
4 ************************************************************************
5  xm2 = 1.402
6  gam2 = 0.174
7  form1 = fpikm(sqrt(s1),ampi,ampi)
8  form1 = form1*wigfor(qq,xm2,gam2)
9 ************************************************************************
10 * new form factor taking into account phase space limitations
11 * for decay K1(1270)->rho(770) K :
12 ************************************************************************
13  xm2 = 1.270
14  gam2 = 0.090
15  amres = amro
16  gamres = gamro
17  am3 = ampi
18  am2 = ampi
19  am1 = amk
20  l1 = 0
21  l2 = 1
22  form1 = bwigk1(qq,xm2,gam2,amres,gamres,am3,am2,am1,l1,l2)
23  form1 = form1*bwigkst(s1,amres,gamres,am2,am3,l2)
24 
25 ************************************************************************
26 * L-DEPENDENT BREIT WIGNER FOR K1. TAKES INTO ACCOUNT CASES WHERE
27 * ONLY A PORTION OF THE BW OF THE SECONDARY RESONANCE IS KINEMATICALLY
28 * ACCESSIBLE (IE; K1(1270)->RHOK).
29 *
30 * SQRT(S) = SAMPLED K1 MASS
31 * M = MASS OF K1 (1270 or 1410)
32 * G = WIDTH OF K1
33 * XMRES0 = MASS OF SECONDARY RESONANCE
34 * GAM0 = WIDTH OF SECONDARY RESONANCE
35 * XMRES1 = MASS OF FIRST DAUGHTER OF SECONDARY RESONANCE
36 * XMRES2 = MASS OF SECOND DAUGHTER OF SECONDARY RESONANCE
37 * XMLEFT = MASS OF SECOND DAUGHTER OF PRIMARY RESONANCE
38 *
39 * FORM TAKEN FROM MANLEY ET AL, 'Multichannel resonance parameterisation
40 * of piN scattering amplitudes', Phys Rev D, vol 45, 4002-4033 (1992).
41 *
42 * L1 IS THE ANG-MOM OF PRIMARY DECAY
43 * L2 IS ANG-MOM OF DECAY OF SECONDARY RESONANCE (RHO OR K*)
44 *
45 * Created: 1997
46 * Author: Sherry Towers
47 ************************************************************************
48 +deck,bwigk1.
49  COMPLEX FUNCTION bwigk1(S,M,G,XMRES0,XGAM0,XMRES1,XMRES2,XMLEFT
50  * ,l1,l2)
51  IMPLICIT NONE
52  real
53  * s,m,g
54  * ,xmres1,xmres2,xmleft
55  * ,mres1,mres2,mleft
56  * ,gam
57  * ,eps,w
58  * ,xmres0,xgam0
59  * ,mres0,gamres
60  * ,rhok1,rhos
61  * ,a,b,c
62 
63  INTEGER l1,l2,n1,n2
64  REAL gauss ! CERNLIB GAUSSIAN INTEGRATION ROUTINE
65  EXTERNAL gauss
66  REAL func
67  EXTERNAL func
68 
69  COMMON /k1mass/ w,mres0,gam0,mres1,mres2,mleft,n1,n2
70 
71  COMPLEX wigner
72  wigner(a,b,c)= cmplx(1.0,0.0)/cmplx(a-b**2,b*c)
73 
74  n1 = l1
75  n2 = l2
76  mres0 = xmres0
77  gam0 = xgam0
78  mres1 = xmres1
79  mres2 = xmres2
80  mleft = xmleft
81 
82  eps = 0.00001
83  w = m
84  rhok1 = gauss(func,xmres1+xmres2,m-xmleft,eps)
85  w = sqrt(s)
86  rhos = gauss(func,xmres1+xmres2,sqrt(s)-xmleft,eps)
87  gam = g*(rhos/rhok1)
88  bwigk1 = (m**2)*wigner(s,m,gam)
89 
90  RETURN
91  END
92 
93 ************************************************************************
94 ************************************************************************
95 * Created: 1997
96 * Author: Sherry Towers
97 ************************************************************************
98 +deck,func.
99  REAL FUNCTION func(X)
100  IMPLICIT NONE
101  real
102  * x,w
103  * ,mres0,mres1,mres2,mleft
104  * ,gam,gam0
105  * ,q,q0
106  * ,pival
107  * ,bwig
108  INTEGER l1,l2
109  COMMON /k1mass/ w,mres0,gam0,mres1,mres2,mleft,l1,l2
110 
111  pival = acos(-1.0)
112 
113  l2 = 1
114  IF (x.GT.(mres1+mres2)) THEN
115  q0 = (mres0**2-(mres1+mres2)**2)*(mres0**2-(mres1-mres2)**2)
116  q0 = sqrt(q0)/(2.0*mres0)
117 
118  q = (x**2-(mres1+mres2)**2)*(x**2-(mres1-mres2)**2)
119  q = sqrt(q)/(2.0*x)
120 
121  gam = gam0*(q/q0)**(2*l2+1)
122  bwig = (x-mres0)**2 + (gam/2.0)**2
123  bwig = (gam/(2.0*pival))/bwig
124  ELSE
125  bwig = 0.0
126  END IF
127 
128  l1 = 0
129  q = (w**2-(mleft+x)**2)*(w**2-(mleft-x)**2)
130  q = sqrt(q)/(2.0*w)
131 
132  func = bwig*(q)**(2*l1+1)/w
133 
134  RETURN
135  END
136 ************************************************************************
137 ************************************************************************
138 * L-DEPENDENT BREIT WIGNER FOR KSTAR(1430),K*(892) or RHO(770)
139 * Created: 1997
140 * Author: Sherry Towers
141 ************************************************************************
142 +deck,bwigkst.
143  COMPLEX FUNCTION bwigkst(S,M,G,XM1,XM2,L)
144  IMPLICIT NONE
145  real
146  * s,m,g
147  * ,xm1,xm2
148  * ,gam,q,q0
149  * ,a,b,c
150  INTEGER l
151  COMPLEX wigner
152  wigner(a,b,c)= cmplx(1.0,0.0)/cmplx(a-b**2,b*c)
153 
154  IF (s.GT.(xm1+xm2)**2.AND.m.GT.(xm1+xm2)) THEN
155  q0 = (m**2-(xm1+xm2)**2)*(m**2-(xm1-xm2)**2)
156  q0 = sqrt(q0)/(2.0*m)
157 
158  q = (s-(xm1+xm2)**2)*(s-(xm1-xm2)**2)
159  q = sqrt(q)/(2.0*sqrt(s))
160 
161  gam = g*(q/q0)**(2*l+1)
162  bwigkst = (m**2)*wigner(s,m,gam)
163  ELSE
164  bwigkst = cmplx(0.0,0.0)
165  END IF
166 
167  RETURN
168  END
169 
170