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Particle Physics Questions : Multiple Choice

 

Q21.The Σ0 baryon, composed of the quark combination uds, is produced through the strong interaction between a π+ meson and a neutron.

What is the quark composition of X?

A neutron is neutral so it must be udd

A positive pion has a charge on +1 so it must be u

Therefore we have : uudd uds + quarks in X

∴ quarks in X = u

Q22. An iodine nucleus decays into a nucleus of Xe−131, a beta-minus particle and particle Y.

Which of the following is a property of particle Y?

A
It has a lepton number of +1
B
It is an antiparticle
C
It is negatively charged
D
It experiences the strong interaction

 

It would have a lepton number of -1 as the nuclei have no lepton numbers and the electron has a lepton number on +1 - therefore A is incorrect.

Therefore it would be an antiparticle - Choice B.

It would have no charge as 53 = 54 -1 so C is wrong

As a lepton it would experience the weak not strong interaction - so D is wrong.

In fact it would be an anti-neutrino....

 

Q23. Which row shows the correct interactions experienced by a hadron or a lepton?

 
Particle
Strong Interaction
Weak Interaction
A
Hadron
Yes
Yes
B
Lepton
Yes
Yes
C
Hadron
Yes
No
D
Lepton
Yes
No

 

Choice A

Q24. What interactions are involved in the production of a strange particle and its decay into non-strange particles?

 
Production
Decay
A
strong
weak
B
strong
strong
C
weak
strong
D
weak
weak

 

Choice A

They contain quarks - produced by the strong interaction, but decay without conservation of strangeness via the weak interaction.