<reaction type="int" weight="float" repeat="*">
   <beam type="Particle_t">
      <momentum px="float" py="float" pz="float" E="float" />
      <properties charge="int" mass="float" />
   </beam>
   <target type="Particle_t">
      <momentum px="float" py="float" pz="float" E="float" />
      <properties charge="int" mass="float" />
   </target>
   <vertex repeat="*">
      <product type="Particle_t" decayVertex="int" repeat="*">
         <momentum px="float" py="float" pz="float" E="float" />
         <properties charge="int" mass="float" />
      </product>
      <origin vx="float" vy="float" vz="float" t="float" />
   </vertex>
</reaction>
