Nhep -> actural number of entry Idhep[Nhep] -> particle id, according to the PDG standards Phep[Nhep][i] -> 4 momenta PHEP(1,IHEP),PHEP(2,IHEP),PHEP(3,IHEP) px,py,pz in GeV PHEP(4,IHEP) energy in GEV PHEP(5,IHEP) mass in GeV Vhep[Nhep][i] -> 4 vertices VHEP(1,IHEP),VHEP(2,IHEP),VHEP(3,IHEP) spatial x,y,z VHEP(4,IHEP) production time in mm/c= 3.33 ps ISTHEP[Nhep] -> particle status code 0 null entry 1 an existing entry w/no decy or fragmentation 2 an entry which has decayed or fragmented IDHEP[Nhep] -> particle identifiers JMOHEP[Nhep] -> mother-daughter relationships JMOHEP(1,IHEP) pointer where the mother is stored JMOHEP(2,IHEP) pointer to the second mother if there are two mother JDAHEP[Nhep] -> pointer to the daughters JDAHEP(1,IHEP) pointer to the first daughter JDAHEP(2,IHEP) pointer to the last daughter Nevhep -> event number MC Parameters Ievt -> Irun -> Param -> Nparam -> Weight ->