BOSS_7.0.2: /home/bes3soft/bes3soft/Boss/7.0.2/dist/7.0.2/Generator/BesEvtGen/BesEvtGen-00-03-58/user/LcLc.C Source File

00001 //---- read out the momentum for each particle, then using them to calculate the amplitude squared, for example:
00002 /*********** using the following decay cards ****************
00003 Particle vpho 4.6 0
00004 Decay vpho
00005 1 Lambda_c+ anti-Lambda_c- PHSP;
00006 Enddecay
00007  
00008 Decay Lambda_c+
00009 1 Lambda0 pi+ PHSP;
00010 Enddecay
00011  
00012 Decay anti-Lambda_c-
00013 1 anti-Lambda0 pi- PHSP;
00014 Enddecay
00015 
00016 Decay Lambda0
00017 1 p+ pi- PHSP;
00018 Enddecay
00019 
00020 Decay anti-Lambda0
00021  1 anti-p- pi+ PHSP;
00022 Enddecay
00023 
00024 End
00025 */
00026 //----------------------------------
00027   EvtVector4R vpho,lambdac,lambdacbar,lambda,lambdabar,proton,antiproton;
00028   vpho      = part->getP4();              //vpho momentum  
00029   lambdac   = part->getDaug(0)->getP4();  //lambda_c+ momentum 
00030   lambdacbar= part->getDaug(1)->getP4();  //anti-Lambda_c-  momentum
00031   lambda    = part->getDaug(0)->getDaug(0)->getP4();  //Lambda momentum
00032   lambdabar = part->getDaug(1)->getDaug(0)->getP4();  //anti-Lambda momentum
00033   proton    = part->getDaug(0)->getDaug(0)->getDaug(0)->getP4();  //proton  
00034   antiproton= part->getDaug(1)->getDaug(0)->getDaug(0)->getP4();  // anti-proton
00035 
00036   EvtHelSys angles0(vpho,lambdac);
00037   double theta0 = angles0.getHelAng(1);
00038   double phi0   = angles0.getHelAng(2);
00039  
00040   EvtHelSys angles1(lambdac,lambda);
00041   double theta1 = angles1.getHelAng(1);
00042   double phi1   = angles1.getHelAng(2);
00043 
00044   EvtHelSys angles2(lambdacbar,lambdabar);
00045   double theta2 = angles2.getHelAng(1);
00046   double phi2   = angles2.getHelAng(2);
00047   
00048   EvtHelSys angles3(lambda,proton);
00049   double theta3 = angles3.getHelAng(1);
00050   double phi3   = angles3.getHelAng(2);
00051 
00052   EvtHelSys angles4(lambdabar,antiproton);
00053   double theta4 = angles4.getHelAng(1);
00054   double phi4   = angles4.getHelAng(2);
00055   
00056   double a0=-0.34;
00057   double alc = -0.91; // for Lambda_c+
00058   double alcb=  0.91; // for anti-Lambda_c-
00059   double al  =  0.642; //Lambda0
00060   double alb = -0.642; //anti-Lambda0
00061 
00062    amps=cos(theta1)*cos(theta2)*cos(theta3)*cos(theta4)*pow(sin(theta0),2)
00063     *al*alb-cos(theta1)*cos(theta2)*cos(theta3)*cos(theta4)*a0*
00064     al*alb-cos(theta1)*cos(theta2)*cos(theta3)*cos(theta4)*al*alb+cos(theta1)*cos(theta2)*cos(theta3)*pow(sin(theta0),2)*al*alcb-cos(theta1)*cos(theta2)*cos(theta3)*a0*al*alcb-cos(theta1)*cos(theta2)*cos(theta3)*al*alcb+cos(theta1)*cos(theta2)*cos(theta4)*pow(sin(theta0),2)*alb*alc-cos(theta1)*cos(theta2)*cos(theta4)*a0*alb*alc-cos(theta1)*cos(theta2)*cos(theta4)*alb*alc+cos(theta1)*cos(theta2)*pow(sin(theta0),2)*alc*alcb-cos(theta1)*cos(theta2)*a0*alc*alcb-cos(theta1)*cos(theta2)*alc*alcb-cos(theta3)*cos(theta4)*pow(sin(theta0),2)*a0*al*alb*alc*alcb+cos(theta3)*cos(theta4)*a0*al*alb*alc*alcb+cos(theta3)*cos(theta4)*al*alb*alc*alcb-cos(theta3)*pow(sin(theta0),2)*a0*al*alc+cos(theta3)*a0*al*alc+cos(theta3)*al*alc-cos(theta4)*pow(sin(theta0),2)*a0*alb*alcb+cos(theta4)*a0*alb*alcb+cos(theta4)*alb*alcb-pow(sin(theta0),2)*a0+a0+1.0;
00065