All Problems

Elementary Particles

Problem 6.298

A stationary neutral particle disintegrated into a proton with kinetic energy \(T=5.3 \mathrm{MeV}\) and a negative pion. Find the mass of that particle. What is its name?

Reveal Answer
m=mp+T+mπ2+T(T+2mp)=1115MeV,aΛparticlem=m_{p}+T+\sqrt{m_{\pi}^{2}+T\left(T+2 m_{p}\right)}=1115 \mathrm{MeV}, \quad \mathrm{a} \Lambda \text {particle}