Explore BrainMass

# Threshold Kinetic Energy

Not what you're looking for? Search our solutions OR ask your own Custom question.

This content was COPIED from BrainMass.com - View the original, and get the already-completed solution here!

What is meant by the threshold energy in a particle reaction? If the threshold energy in a particle reaction holds, what can you say about the motion of the particles in the centre of momentum frame? What does this imply about the motion of the particles in the original laboratory frame?

Two photons of energies E1 and E2 collide with their incident directions of motion making an angle theta with respect to each other. The collision annihilates the two photons and produces two new particles of equal rest mass m. Show that at threshold the condition holds:

(E1)(E2)(sin^2(theta/2)) = (m^2)(c^4)

© BrainMass Inc. brainmass.com October 7, 2022, 9:30 am ad1c9bdddf
https://brainmass.com/physics/gamma/threshold-kinetic-energy-31786

#### Solution Preview

Hi.

Please refer to the attached MS Word document for the full solution.

p + p --> p + p + pi + pi

The protons have mass M, the pions have mass m. Set c = 1.

A: K = E - M. gamma = E/M = K/M + 1. These relations can be used to define the ...

#### Solution Summary

This solution includes three pages of calculations and explanation attached. 400 words.

\$2.49