00001 subroutine s2n_init()
00002 implicit none
00003 include 's2n_declare.h'
00004 real*8 gf_gf
00005 integer init
00006 data init /0/
00007
00008 if (init.eq.0) then
00009 init=1
00010 print*, ""
00011 print*, " ####################################################################"
00012 print*, " # #"
00013 print*, " # ====================== #"
00014 print*, " # SANC, Version: 1.10 #"
00015 print*, " # ====================== #"
00016 print*, " # #"
00017 print*, " # SANC - NLO Standard Model corrections to the HEP processes #"
00018 print*, " # #"
00019 print*, " # Ref: A. Andonov et al., 'SANCscope - v.1.00', #"
00020 print*, " # Comput. Phys. Commun. 174, 481 (2006). #"
00021 print*, " # #"
00022 print*, " # http://sanc.jinr.ru, http://pcphsanc.cern.ch #"
00023 print*, " # #"
00024 print*, " ####################################################################"
00025 print*, ""
00026 if (gfscheme.eq.0) then
00027 print *, "Alpha scheme"
00028 elseif (gfscheme.eq.1) then
00029 print *, "GFermi scheme"
00030 elseif (gfscheme.eq.2) then
00031 print *, "GFermi prime scheme"
00032 endif
00033
00034 endif
00035
00036 pi = 4d0*atan(1d0)
00037 sr2 = sqrt(2d0)
00038 i_ = dcmplx(0d0,1d0)
00039 cfl = 1d0
00040 cfq = 3d0
00041
00042 qf( 1) = 0d0
00043 qf( 2) = -1d0
00044 qf( 3) = 0d0
00045 qf( 4) = -1d0
00046 qf( 5) = 0d0
00047 qf( 6) = -1d0
00048 qf( 7) = 2d0/3d0
00049 qf( 8) = -1d0/3d0
00050 qf( 9) = 2d0/3d0
00051 qf(10) = -1d0/3d0
00052 qf(11) = 2d0/3d0
00053 qf(12) = -1d0/3d0
00054
00055 i3f( 1) = .5d0
00056 i3f( 2) = -.5d0
00057 i3f( 3) = .5d0
00058 i3f( 4) = -.5d0
00059 i3f( 5) = .5d0
00060 i3f( 6) = -.5d0
00061 i3f( 7) = .5d0
00062 i3f( 8) = -.5d0
00063 i3f( 9) = .5d0
00064 i3f(10) = -.5d0
00065 i3f(11) = .5d0
00066 i3f(12) = -.5d0
00067
00068 ram2 = ma**2
00069 rvm2 = mv**2
00070 rhm2 = mh**2
00071 rzm2 = mz**2
00072 rwm2 = mw**2
00073 renm2 = men**2
00074 relm2 = mel**2
00075 rupm2 = mup**2
00076 rdnm2 = mdn**2
00077 rmnm2 = mmn**2
00078 rmom2 = mmo**2
00079 rchm2 = mch**2
00080 rstm2 = mst**2
00081 rtnm2 = mtn**2
00082 rtam2 = mta**2
00083 rtpm2 = mtp**2
00084 rbtm2 = mbt**2
00085
00086 ctw2 = rwm2/rzm2
00087 stw2 = 1d0-ctw2
00088 ctw4 = ctw2**2
00089 stw4 = stw2**2
00090 ctw6 = ctw2**3
00091 stw6 = stw2**3
00092 ctw = mw/mz
00093 stw = sqrt(1d0-ctw2)
00094
00095 rwz = ctw2
00096 rhz = rhm2/rzm2
00097 rhw = rhm2/rwm2
00098 renh = renm2/rhm2
00099 relh = relm2/rhm2
00100 ruph = rupm2/rhm2
00101 rdnh = rdnm2/rhm2
00102 rmnh = rmnm2/rhm2
00103 rmoh = rmom2/rhm2
00104 rchh = rchm2/rhm2
00105 rsth = rstm2/rhm2
00106 rtnh = rtnm2/rhm2
00107 rtah = rtam2/rhm2
00108 rtph = rtpm2/rhm2
00109 rbth = rbtm2/rhm2
00110 renz = renm2/rzm2
00111 relz = relm2/rzm2
00112 rupz = rupm2/rzm2
00113 rdnz = rdnm2/rzm2
00114 rmnz = rmnm2/rzm2
00115 rmoz = rmom2/rzm2
00116 rchz = rchm2/rzm2
00117 rstz = rstm2/rzm2
00118 rtnz = rtnm2/rzm2
00119 rtaz = rtam2/rzm2
00120 rtpz = rtpm2/rzm2
00121 rbtz = rbtm2/rzm2
00122 renw = renm2/rwm2
00123 relw = relm2/rwm2
00124 rupw = rupm2/rwm2
00125 rdnw = rdnm2/rwm2
00126 rmnw = rmnm2/rwm2
00127 rmow = rmom2/rwm2
00128 rchw = rchm2/rwm2
00129 rstw = rstm2/rwm2
00130 rtnw = rtnm2/rwm2
00131 rtaw = rtam2/rwm2
00132 rtpw = rtpm2/rwm2
00133 rbtw = rbtm2/rwm2
00134
00135 cm2 = dcmplx(0d0, -1d-30)
00136 vm2 = dcmplx(rvm2,-1d-30)
00137 hm2 = dcmplx(rhm2,-1d-30)
00138 zm2 = dcmplx(rzm2,-1d-30)
00139 wm2 = dcmplx(rwm2,-1d-30)
00140 enm2 = dcmplx(renm2,-1d-30)
00141 elm2 = dcmplx(relm2,-1d-30)
00142 upm2 = dcmplx(rupm2,-1d-30)
00143 dnm2 = dcmplx(rdnm2,-1d-30)
00144 mnm2 = dcmplx(rmnm2,-1d-30)
00145 mom2 = dcmplx(rmom2,-1d-30)
00146 chm2 = dcmplx(rchm2,-1d-30)
00147 stm2 = dcmplx(rstm2,-1d-30)
00148 tnm2 = dcmplx(rtnm2,-1d-30)
00149 tam2 = dcmplx(rtam2,-1d-30)
00150 tpm2 = dcmplx(rtpm2,-1d-30)
00151 btm2 = dcmplx(rbtm2,-1d-30)
00152
00153 qen = qf(1)
00154 qel = qf(2)
00155 qup = qf(7)
00156 qdn = qf(8)
00157 qmn = qf(3)
00158 qmo = qf(4)
00159 qch = qf(9)
00160 qst = qf(10)
00161 qtn = qf(5)
00162 qta = qf(6)
00163 qtp = qf(11)
00164 qbt = qf(12)
00165
00166 aen = i3f(1)
00167 ael = i3f(2)
00168 aup = i3f(7)
00169 adn = i3f(8)
00170 amn = i3f(3)
00171 amo = i3f(4)
00172 ach = i3f(9)
00173 ast = i3f(10)
00174 atn = i3f(5)
00175 ata = i3f(6)
00176 atp = i3f(11)
00177 abt = i3f(12)
00178
00179 ven = aen-2d0*qen*stw2
00180 vel = ael-2d0*qel*stw2
00181 vup = aup-2d0*qup*stw2
00182 vdn = adn-2d0*qdn*stw2
00183 vmn = amn-2d0*qmn*stw2
00184 vmo = amo-2d0*qmo*stw2
00185 vch = ach-2d0*qch*stw2
00186 vst = ast-2d0*qst*stw2
00187 vtn = atn-2d0*qtn*stw2
00188 vta = ata-2d0*qta*stw2
00189 vtp = atp-2d0*qtp*stw2
00190 vbt = abt-2d0*qbt*stw2
00191
00192 dfen = (ven-aen)/aen
00193 dfel = (vel-ael)/ael
00194 dfup = (vup-aup)/aup
00195 dfdn = (vdn-adn)/adn
00196 dfmn = (vmn-amn)/amn
00197 dfmo = (vmo-amo)/amo
00198 dfch = (vch-ach)/ach
00199 dfst = (vst-ast)/ast
00200 dftn = (vtn-atn)/atn
00201 dfta = (vta-ata)/ata
00202 dftp = (vtp-atp)/atp
00203 dfbt = (vbt-abt)/abt
00204
00205 vpaen = ven+aen
00206 vmaen = ven-aen
00207 vpael = vel+ael
00208 vmael = vel-ael
00209 vpaup = vup+aup
00210 vmaup = vup-aup
00211 vpadn = vdn+adn
00212 vmadn = vdn-adn
00213 vpamn = vmn+amn
00214 vmamn = vmn-amn
00215 vpamo = vmo+amo
00216 vmamo = vmo-amo
00217 vpach = vch+ach
00218 vmach = vch-ach
00219 vpast = vst+ast
00220 vmast = vst-ast
00221 vpatn = vtn+atn
00222 vmatn = vtn-atn
00223 vpata = vta+ata
00224 vmata = vta-ata
00225 vpatp = vtp+atp
00226 vmatp = vtp-atp
00227 vpabt = vbt+abt
00228 vmabt = vbt-abt
00229
00230 gz = mz*wz
00231 mz2 = dcmplx(rzm2,-gz)
00232 mz2c = dconjg(mz2)
00233 gw = mw*ww
00234 mw2 = dcmplx(rwm2,-gw)
00235 mw2c = dconjg(mw2)
00236 gh = mh*wh
00237 mh2 = dcmplx(rhm2,-gh)
00238 mh2c = dconjg(mh2)
00239 gtp = mtp*wtp
00240 mtp2 = dcmplx(rtpm2,-gtp)
00241 mtp2c = dconjg(mtp2)
00242
00243 gf_gf = gf
00244 gf = pi/alphai/sqrt(2d0)/stw2/ctw2/rzm2
00245 cfscheme = gf/gf_gf
00246 if (gfscheme.eq.0) then
00247 cfscheme = 1d0
00248
00249 elseif (gfscheme.eq.1) then
00250 gf = gf_gf
00251
00252 elseif (gfscheme.eq.2) then
00253 gf = gf_gf
00254 alphai = pi/gf/sqrt(2d0)/stw2/ctw2/rzm2
00255
00256 endif
00257 alpha = 1d0/alphai
00258 e = sqrt(4d0*pi*alpha)
00259 g = sqrt(gf/sr2*8d0*rzm2*ctw2)
00260 gs = sqrt(4d0*pi*alphas)
00261
00262 thmu = mw
00263 thmu2 = thmu**2
00264 omega = 0.001d0
00265
00266 return
00267 end
