Analysis Software
Documentation for sPHENIX simulation software
 All Classes Namespaces Files Functions Variables Typedefs Enumerations Enumerator Friends Macros Groups Pages
pytbhq.f
Go to the documentation of this file. Or view the newest version in sPHENIX GitHub for file pytbhq.f
1 C---------------------------------------------------------
2 C 2) Q QBAR ->TBH^+
3  SUBROUTINE pytbhq(Q1,Q2,P1,P2,P3,MT,MB,RMB,MHP,AMP2)
4 C
5 C AMP2(OUTPUT) =MATRIX ELEMENT (AMPLITUDE**2) FOR Q QBAR->TB H^+
6 C (NB SAME STRUCTURE AS FOR PYTBHG ROUTINE ABOVE)
7  IMPLICIT DOUBLE PRECISION(a-h, o-z)
8  IMPLICIT INTEGER(i-n)
9  DOUBLE PRECISION mw2,mt,mb,mhp,mw
10  dimension q1(4),q2(4),p1(4),p2(4),p3(4)
11  common/pydat1/mstu(200),paru(200),mstj(200),parj(200)
12  common/pydat2/kchg(500,4),pmas(500,4),parf(2000),vckm(4,4)
13  common/pymssm/imss(0:99),rmss(0:99)
14  common/pyctbh/ alpha,alphas,sw2,mw2,tanb,vtb,v,a
15  SAVE /pydat1/,/pydat2/,/pymssm/,/pyctbh/
16 C !THE RELEVANT INPUT PARAMETERS ABOVE ARE NEEDED FOR CALCULATION
17 C BUT ARE NOT DEFINED HERE SO THAT ONE MAY CHOOSE/VARY THEIR VALUES:
18 C ACCORDINGLY, WHEN CALLING THESE SUBROUTINES, PLEASE SUPPLY VIA
19 C THIS COMMON/PARAM/ YOUR PREFERRED ALPHA, ALPHAS,..AND TANB VALUES
20 C
21 C THE NORMALIZED V,A COUPLINGS ARE DEFINED BELOW AND USED BOTH
22 C IN THIS ROUTINE AND IN THE TOP WIDTH CALCULATION PYTBHB(..).
23 C
24  dimension yy(2,2)
25 
26  pi = 4*datan(1.d0)
27  mw = dsqrt(mw2)
28 
29 C COLLECTING THE RELEVANT OVERALL FACTORS:
30 C 3X3 INITIAL QUARK COLOR AVERAGE, 2X2 QUARK SPIN AVERAGE
31  ps=1.d0/(3.d0*3.d0 *2.d0*2.d0)
32 C COUPLING CONSTANT (OVERALL NORMALIZATION)
33  fact=(4.d0*pi*alpha)*(4.d0*pi*alphas)**2/sw2/2.d0
34 C NB ALPHA IS E^2/4/PI, BUT BETTER DEFINED IN TERMS OF G_FERMI:
35 C ALPHA= DSQRT(2.D0)*GF*SW2*MW**2/PI
36 C ALPHAS IS ALPHA_STRONG;
37 C SW2 IS SIN(THETA_W)**2.
38 C
39 C VTB=.998D0
40 C VTB IS TOP-BOTTOM CKM MATRIX ELEMENT (APPROXIMATE VALUE HERE)
41 C
42  v = ( mt/mw/tanb +rmb/mw*tanb)/2.d0
43  a = (-mt/mw/tanb +rmb/mw*tanb)/2.d0
44 C V AND A ARE (NORMALIZED) VECTOR AND AXIAL TBH^+ COUPLINGS
45 C
46 C REDEFINING P2 INGOING FROM OVERALL MOMENTUM CONSERVATION
47 C (BECAUSE P2 INGOING WAS USED IN OUR GRAPH CALCULATION CONVENTIONS)
48  DO 100 kk=1,4
49  p2(kk)=p3(kk)-q1(kk)-q2(kk)+p1(kk)
50  100 CONTINUE
51 C DEFINING VARIOUS RELEVANT 4-SCALAR PRODUCTS:
52  s = 2*pytbhs(q1,q2)
53  p1q1=pytbhs(q1,p1)
54  p1q2=pytbhs(p1,q2)
55  p2q1=pytbhs(p2,q1)
56  p2q2=pytbhs(p2,q2)
57  p1p2=pytbhs(p1,p2)
58 C
59 C TOP WIDTH CALCULATION
60  CALL pytbhb(mt,mb,mhp,br,gamt)
61 C GAMT IS THE TOP WIDTH: T->BH^+ AND/OR T->B W^+
62 C THEN DEFINE TOP (RESONANT) PROPAGATOR:
63  a1inv= s -2*p1q1 -2*p1q2
64  a1 =a1inv/(a1inv**2+ (gamt*mt)**2)
65 C (I.E. INTRODUCE THE TOP WIDTH IN A1 TO REGULARISE THE POLE)
66 C NB A12 = A1*A1 BUT WITH CORRECT WIDTH TREATMENT
67  a12 = 1.d0/(a1inv**2+ (gamt*mt)**2)
68  a2 =1.d0/(s +2*p2q1 +2*p2q2)
69 C NOTE A2 IS B PROPAGATOR, DOES NOT NEED A WIDTH
70 C NOW COMES THE AMP**2:
71 C NB COLOR FACTOR (COMING FORM GRAPHS) ALREADY INCLUDED IN
72 C THE EXPRESSIONS BELOW
73  yy(1, 1) = -16*a**2*a2**2*mb*mt+
74  &64*a**2*a2**2*p1q2*p2q1**2/s**2+
75  &128*a**2*a2**2*mb*mt*p2q1*p2q2/s**2-
76  &128*a**2*a2**2*p1p2*p2q1*p2q2/s**2-
77  &64*a**2*a2**2*p1q1*p2q1*p2q2/s**2-
78  &64*a**2*a2**2*p1q2*p2q1*p2q2/s**2+
79  &64*a**2*a2**2*p1q1*p2q2**2/s**2-
80  &32*a**2*a2**2*mb**3*mt/s+32*a**2*a2**2*mb**2*p1p2/s+
81  &32*a**2*a2**2*mb**2*p1q1/s+32*a**2*a2**2*mb**2*p1q2/s-
82  &32*a**2*a2**2*p1p2*p2q1/s-32*a**2*a2**2*p1q1*p2q1/s-
83  &32*a**2*a2**2*p1p2*p2q2/s-32*a**2*a2**2*p1q2*p2q2/s+
84  &16*a2**2*mb*mt*v**2+64*a2**2*p1q2*p2q1**2*v**2/s**2-
85  &128*a2**2*mb*mt*p2q1*p2q2*v**2/s**2-
86  &128*a2**2*p1p2*p2q1*p2q2*v**2/s**2-
87  &64*a2**2*p1q1*p2q1*p2q2*v**2/s**2-
88  &64*a2**2*p1q2*p2q1*p2q2*v**2/s**2+
89  &64*a2**2*p1q1*p2q2**2*v**2/s**2
90  yy(1, 1)=yy(1, 1)+32*a2**2*mb**3*mt*v**2/s+
91  &32*a2**2*mb**2*p1p2*v**2/s+
92  &32*a2**2*mb**2*p1q1*v**2/s+32*a2**2*mb**2*p1q2*v**2/s-
93  &32*a2**2*p1p2*p2q1*v**2/s-32*a2**2*p1q1*p2q1*v**2/s-
94  &32*a2**2*p1p2*p2q2*v**2/s-32*a2**2*p1q2*p2q2*v**2/s
95  yy(1, 1)=2*yy(1, 1)
96 
97  yy(1, 2) = -32*a**2*a1*a2*mb*mt+
98  &128*a**2*a1*a2*mb*mt*p1q2*p2q1/s**2-
99  &128*a**2*a1*a2*p1p2*p1q2*p2q1/s**2+
100  &64*a**2*a1*a2*p1q1*p1q2*p2q1/s**2-
101  &64*a**2*a1*a2*p1q2**2*p2q1/s**2+
102  &64*a**2*a1*a2*p1q2*p2q1**2/s**2+
103  &128*a**2*a1*a2*mb*mt*p1q1*p2q2/s**2-
104  &128*a**2*a1*a2*p1p2*p1q1*p2q2/s**2-
105  &64*a**2*a1*a2*p1q1**2*p2q2/s**2+
106  &64*a**2*a1*a2*p1q1*p1q2*p2q2/s**2-
107  &64*a**2*a1*a2*p1q1*p2q1*p2q2/s**2-
108  &64*a**2*a1*a2*p1q2*p2q1*p2q2/s**2+
109  &64*a**2*a1*a2*p1q1*p2q2**2/s**2-
110  &64*a**2*a1*a2*mb*mt*p1p2/s+
111  &64*a**2*a1*a2*p1p2**2/s+32*a**2*a1*a2*mb**2*p1q1/s+
112  &32*a**2*a1*a2*p1p2*p1q1/s+32*a**2*a1*a2*mb**2*p1q2/s+
113  &32*a**2*a1*a2*p1p2*p1q2/s-32*a**2*a1*a2*mt**2*p2q1/s
114  yy(1, 2)=yy(1, 2)-32*a**2*a1*a2*p1p2*p2q1/s-
115  &64*a**2*a1*a2*p1q1*p2q1/s-
116  &32*a**2*a1*a2*mt**2*p2q2/s-32*a**2*a1*a2*p1p2*p2q2/s-
117  &64*a**2*a1*a2*p1q2*p2q2/s+32*a1*a2*mb*mt*v**2-
118  &128*a1*a2*mb*mt*p1q2*p2q1*v**2/s**2 -
119  &128*a1*a2*p1p2*p1q2*p2q1*v**2/s**2+
120  &64*a1*a2*p1q1*p1q2*p2q1*v**2/s**2-
121  &64*a1*a2*p1q2**2*p2q1*v**2/s**2+
122  &64*a1*a2*p1q2*p2q1**2*v**2/s**2-
123  &128*a1*a2*mb*mt*p1q1*p2q2*v**2/s**2-
124  &128*a1*a2*p1p2*p1q1*p2q2*v**2/s**2-
125  &64*a1*a2*p1q1**2*p2q2*v**2/s**2+
126  &64*a1*a2*p1q1*p1q2*p2q2*v**2/s**2-
127  &64*a1*a2*p1q1*p2q1*p2q2*v**2/s**2-
128  &64*a1*a2*p1q2*p2q1*p2q2*v**2/s**2+
129  &64*a1*a2*p1q1*p2q2**2*v**2/s**2+
130  &64*a1*a2*mb*mt*p1p2*v**2/s+64*a1*a2*p1p2**2*v**2/s
131  yy(1, 2)=yy(1, 2)+32*a1*a2*mb**2*p1q1*v**2/s+
132  &32*a1*a2*p1p2*p1q1*v**2/s+
133  &32*a1*a2*mb**2*p1q2*v**2/s+32*a1*a2*p1p2*p1q2*v**2/s-
134  &32*a1*a2*mt**2*p2q1*v**2/s-32*a1*a2*p1p2*p2q1*v**2/s-
135  &64*a1*a2*p1q1*p2q1*v**2/s-32*a1*a2*mt**2*p2q2*v**2/s-
136  &32*a1*a2*p1p2*p2q2*v**2/s-64*a1*a2*p1q2*p2q2*v**2/s
137 
138 
139  yy(2, 2) =-16*a**2*a12*mb*mt+
140  &128*a**2*a12*mb*mt*p1q1*p1q2/s**2-
141  &128*a**2*a12*p1p2*p1q1*p1q2/s**2+
142  &64*a**2*a12*p1q1*p1q2*p2q1/s**2-
143  &64*a**2*a12*p1q2**2*p2q1/s**2-64*a**2*a12*p1q1**2*p2q2/s**2+
144  &64*a**2*a12*p1q1*p1q2*p2q2/s**2-32*a**2*a12*mb*mt**3/s+
145  &32*a**2*a12*mt**2*p1p2/s+32*a**2*a12*p1p2*p1q1/s+
146  &32*a**2*a12*p1p2*p1q2/s-32*a**2*a12*mt**2*p2q1/s-
147  &32*a**2*a12*p1q1*p2q1/s-32*a**2*a12*mt**2*p2q2/s-
148  &32*a**2*a12*p1q2*p2q2/s+16*a12*mb*mt*v**2-
149  &128*a12*mb*mt*p1q1*p1q2*v**2/s**2-
150  &128*a12*p1p2*p1q1*p1q2*v**2/s**2+
151  &64*a12*p1q1*p1q2*p2q1*v**2/s**2-
152  &64*a12*p1q2**2*p2q1*v**2/s**2-64*a12*p1q1**2*p2q2*v**2/s**2+
153  &64*a12*p1q1*p1q2*p2q2*v**2/s**2+32*a12*mb*mt**3*v**2/s+
154  &32*a12*mt**2*p1p2*v**2/s+32*a12*p1p2*p1q1*v**2/s+
155  &32*a12*p1p2*p1q2*v**2/s-32*a12*mt**2*p2q1*v**2/s
156  yy(2, 2)=yy(2, 2)-32*a12*p1q1*p2q1*v**2/s-
157  &32*a12*mt**2*p2q2*v**2/s-
158  &32*a12*p1q2*p2q2*v**2/s
159  yy(2, 2)=2*yy(2, 2)
160 
161  res=yy(1,1)+2*yy(1,2)+yy(2,2)
162  amp2= fact*ps*vtb**2*res
163 
164  END