c======================================================================= c smuon.for c If you copy this code, please send a message to c RIDOLFI@VXCERN.CERN.CH c or to c MLM@VXCERN.CERN.CH c so that we can keep you informed of upgrades or modifications. c======================================================================= implicit real*8 (a-h,o-z) parameter(sin2w=.232d0,xmz=91.188d0,gz=2.5d0) common/prcpar/xm1,xm2,cphi,iproc common/beams/s,sthr common/bveg1/xl(10),xu(10),acc,ndim,ncall,itmx,nprn character*2 ipro(3) data ipro/'RR','LL','LR'/ external radsig c c Initialize parameters for Vegas do j=1,10 xl(j) = 0 xu(j) = 1 enddo acc = -1 ndim = 1 ncall = 10000 itmx = 4 1 write(*,*)'Enter sqrt(s), m(smu_R), m(smu_L), Iproc ', + ' (Iproc=1 for RR, 2 for LL, 3 for LR)' read(*,*)sr,xm1,xm2,iproc if(sr.lt.0) stop s=sr**2 if(iproc.eq.1) then sthr=4*xm1**2 cphi=0 elseif(iproc.eq.2) then sthr=4*xm2**2 cphi=1 elseif(iproc.eq.3) then write(*,*) 'input R-L mixing angle' read(*,*) acphi cphi=acos(acphi) sthr=(xm1+xm2)**2 endif c no isr xsect0=sig(s) c with isr call vegas(radsig,xsect1,sd,chisq) c output write(*,*)' m(smuL) = ',xm1,'GeV',' m(smuR) = ',xm2,'GeV' write(*,*)' ',ipro(iproc),' xsec no isr =',xsect0,'pb' write(*,*)' ',ipro(iproc),' xsec with isr =',xsect1,'pb' if(sr.ne.srold) then write(1,100) sr srold=sr endif write(1,101) xm1,xm2 write(1,102) ipro(iproc),xsect0 write(1,103) ipro(iproc),xsect1 goto 1 100 format(' Ecm = ',g10.4,'GeV') 101 format(' m(smuL) = ',g10.4,'GeV',' m(smuR) = ',g10.4,'GeV') 102 format(' ',A2,' xsec no isr (pb) =',g10.4) 103 format(' ',A2,' xsec with isr (pb) =',g10.4) goto 1 end c------------------------------------------------------------------------- c Cross section for smuon production in e+e- collisions c Z. Phys. C34(1987)411 function sig(s) c GeV to microbarn conversion factor: sigma (pb) = hc2 * sigma (GeV^-2) c iproc=1 => sigma(smu1 smu1) c iproc=2 => sigma(smu2 smu2) c iproc=3 => sigma(smu1 smu2) c------------------------------------------------------------------------- implicit real*8 (a-h,o-z) common/prcpar/xm1,xm2,cphi,iproc parameter(hc2=3.8937966d8) parameter(sin2w=.232d0,xmz=91.188d0,gz=2.5d0) if(iproc.eq.1) then rm1=xm1 rm2=xm1 elseif(iproc.eq.2) then rm1=xm2 rm2=xm2 elseif(iproc.eq.3) then rm1=xm1 rm2=xm2 endif cos2w=1-sin2w sw=sqrt(sin2w) cw=sqrt(cos2w) sphi=sqrt(1.-cphi**2) pi=acos(-1.d0) aem=alfa(s) g=sqrt(4*pi*aem/sin2w) e=sqrt(4*pi*aem) ell=-.5d0+sin2w elr=sin2w dzq=1.d0/((s-xmz**2)**2+(gz*xmz)**2) redz=(s-xmz**2)*dzq del=1+(rm1**2-rm2**2)/s beta1=sqrt(1-4*rm1**2/(s*del**2)) c ff is the integral of (u*t-m1**2*m2**2) over t ff=(beta1*s*del)**3/6. if(iproc.lt.3)then sigp=e**4/(8*pi*s**4)*ff sigz=g**4/(16*pi*s**2*cos2w**2)*ff*dzq # *(ell*cphi**2+elr*sphi**2)**2*(ell**2+elr**2) sigzp=(e*g)**2/(8*pi*s**3*cos2w)*ff*redz # *(ell*cphi**2+elr*sphi**2)*(ell+elr) sig=(sigp+sigz+sigzp)*hc2 elseif(iproc.eq.3)then sigz=g**4/(16*pi*s**2*cos2w**2)*ff*dzq*cphi**2*sphi**2 # *(ell-elr)**2*(ell**2+elr**2) sig=sigz*hc2 endif end