Question

The strangeness conservation law does not hold in
1. π⁰ = γ + γ
2. \(\bar \mu + p \to n + {\mu ^ + } + \gamma \)
3. A⁰ → p + π
4. A⁰ + p → ε⁺ + n

Answer 1

Correct Answer - Option 3 : A⁰ → p + π

Concept:

• During the research, scientist found that there were a large number of particle which behaved in a very strange manner.

• They were produced by strong electromagnetic interaction.

• They decay via weak interactions.

• The quantum number associated with that particle is named as strangeness numbers.

Conservation:

• Strangeness number are conserved in EM/strong interaction.

• They are not conserved in weak interactions.

Some strangeness numbers and their values 

Particle Name	Symbol	Anti-particle	Baryon	Electron Lapton	Muon Lapton	Tau Lapton	Strangeness number
			B	Le	Lμ	LT	S
Photon	γ	self	0	0	0	0	0
Pion	π+	π-		0	0	0	0
Pion	π0	self	0	0	0	0	0
Muon	μ-	μ+	0	0	+1 , -1	0	0
Photon	p	p̅	+1, -1	0	0	0	0
Nutron	n	n̅	+1, -1	0	0	0	0
Omega	Ω-	Ω+	+1, -1	0	0	0	-3, +3
Labda	A0	A̅0	+1, -1	0	0	0	-1, +1
electron	e-	e+	0	+1, -1	0	0	0

Calculation:

We can check conservation by balancing the quantum number on both sides of the reaction by using the above data.

π⁰ = γ + γ

 0     0    0

\(̅ \mu + p \to n + {\mu ^ + } + \gamma \)

 0    0     0     0       0

A⁰ → p + π

-1     0     0

A⁰ + p → ε+ + n

-1     0     -1     0

 0     0      0      0

From the above discussion, we can see that, strangeness conservation law does not hold in A⁰ → p + π.