Question

For the reaction p + p → p + Λ + K+ calculate the threshold energy and the invariant mass of the system at threshold energy. The rest energies of the p, Λ and K+ are respectively 938, 1,115 and 494 MeV

Answer 1

Tthr = [(mp + mΛ + mk)2 − (2mp)2 ]/2mp

= [(0.938 + 1.115 + 0.494)2 − (2 × 0.938)2]/2 × 0.938

= 1.58 GeV