Lecture 3

Question 1

Four vector scalar product: GO

Answer 1

u = upper, l = lower:

au * bl = al * bu = a0ub0l + a1ub1l + ….
= a0ub0u - a1ub1u - …..

Question 2

What changes with elastic scattering and what stays the same?

Answer 2

Changes: momentum
Same: the particles at initial and final

Question 3

What changes with inelastic scattering?

Answer 3

The particles in final state are different from initial state. annihilation

Question 4

What are the three channels of Mandelstam variables?

Answer 4

s, t, u

Question 5

s = ?

Answer 5

s = (p1 + p2)^2

Question 6

t = ?

Answer 6

(p1 - p3)^2

Question 7

u = ?

Answer 7

(p1 - p4)^2

Question 8

What is s = in terms in E?

Answer 8

s = (E1* + E2*)^2

Question 9

What is the rate of the decay process called?

Answer 9

Decay rate

Question 10

What is conserved in the decay?

Answer 10

Four momentum. pA = p1 + p2

Question 11

Which Rule gives us the transition rate?

Answer 11

Fermi’s Golden Rule

Question 12

The decay rate time is inversely proportional to what?

Answer 12

Energy of the decaying particle